Published records
The 953 records this release publishes. Each is cited by its identifier rather than by a URL, and each shows what it rests on.
This is not the register. Most records in this base are not published, and a record reaches this list only by passing every gate rule and then being cleared individually. What is held back, and why.
| Record | In plain language | Layer | Tier | Confidence |
|---|---|---|---|---|
| CLM-0001 | The UK government's own feasibility study describes a system beaming microwaves at about 230 watts per square metre onto the ground. | VC06, VC07 | T4 | HIGH |
| CLM-0002 | The summary report says the beam is strongest at the middle of the receiving site, at about 240 watts per square metre, and argues that this makes it safe because sunlight is stronger. | VC06, VC07 | T4 | HIGH |
| CLM-0003 | The report gives the receiving site as an ellipse roughly 7 km by 13 km, and states a beam strength of 245 watts per square metre. | VC07 | T4 | HIGH |
| CLM-0004 | The author of the 2019 CASSIOPeiA paper states the beam's strongest point is about 230 watts per square metre, and says that figure was chosen because it makes the economics work. | VC06 | T2 | HIGH |
| CLM-0005 | A second figure of 29 watts per square metre appears in the same report, but it measures electricity produced per unit of land, not beam strength. The two are different things and must not be compared. | VC07, XC03 | T0 | HIGH |
| CLM-0006 | None of the five main studies mentions the international radio-frequency exposure limits, or any safety standard, or a restricted area around the receiving site. | VC06, XC01 | T0 | HIGH |
| CLM-0007 | The UK study's own experts expect the beam to interfere with electronics in its path, and think it unlikely to have much effect outside the receiving site. | VC06, XC01 | T4 | MED |
| CLM-0008 | The international exposure guideline allows 10 watts per square metre for the general public and 50 for workers, at the frequencies space solar power would use. | XC01 | T1 | HIGH |
| CLM-0009 | For the UK reference design, averaging the limit over half an hour and over a whole body does not help, because the beam does not switch off and it is far wider than a person. | VC06, XC01 | T0 | MED |
| CLM-0010 | At its strongest, the beam is around 23 times the level the international guideline sets for the general public, and around 5 times the level set for workers. | VC06, VC07, XC01 | T0 | MED |
| CLM-0013 | The paper that modern UK studies rely on for the beam figure calls anything below 1 kilowatt per square metre safe, with 230 watts per square metre as the typical value, and cites nothing at all to support the word safe. | VC06, XC01 | T3 | HIGH |
| CLM-0015 | An independent Japanese authority on power beaming records the American reference design's beam strength as 23 milliwatts per square centimetre at the receiving site, which is 230 watts per square metre. | VC05, VC06, VC07 | T2 | MED |
| CLM-0017 | One author, writing in an unpublished draft, says the exposure guideline must be met outside the receiving site, and that what applies inside the site is still under discussion. | VC07, XC01 | T2 | MED |
| CLM-0018 | The most recent UK government report calls 230 watts per square metre a limit to be reached because it lowers cost, and cites an earlier report by the same consultancy as the reason for using it. | VC06, XC02 | T4 | HIGH |
| CLM-0019 | The report sets out Space Solar's plan: a small in-orbit test, then 31 megawatts in 2030, 150 megawatts in 2033, and 650 megawatts in geostationary orbit in 2036. | VC10, VC11, XC02 | T4 | MED |
| CLM-0020 | The original 1978 design set the beam at 230 watts per square metre in the middle of the receiving site, about one twenty-third of that at its edge, and about one two-hundred-and-thirtieth of that at a fenced boundary further out. | VC06, VC07 | T3 | HIGH |
| CLM-0023 | In the 1978 reference design, two limits set the size of the transmitter and the receiving site: how much heat the transmitter can shed, and an upper limit on beam strength taken from studies of the ionosphere. | VC05, VC06, XC02 | T3 | HIGH |
| CLM-0024 | The American standard of the day allowed 100 watts per square metre averaged over six minutes. The US had no separate limit for the public in 1980, though Canada had just set one of 10 watts per square metre for continuous public exposure. | XC01 | T3 | HIGH |
| CLM-0030 | A 2026 search found no test of the effect at the frequency space solar power would use. The facilities that can heat the ionosphere work at radio frequencies a thousand times lower. | VC06, XC03 | T2 | MED |
| CLM-0032 | In 2007 the international radio science union published a white paper saying that nobody had measured this heating effect from the ground at these frequencies, and only calculations existed. The 1978 figure was repeated not in that white paper but in the longer report attached to it, which is a separate document. | VC06, XC01 | T4 | HIGH |
| CLM-0033 | Apart from a 1981 NASA review that found no evidence for the number and suggested a higher one, nobody was found to have revisited it, and a 2014 proposal for experiments on beam effects in the atmosphere does not appear to have gone ahead. | VC06 | T5 | LOW |
| CLM-0036 | The 1980 American assessment said people living or working near the receiving site, outside its exclusion boundary, would generally be exposed to much less than 0.1 milliwatts per square centimetre, and that anyone entering the site for work could be exposed to up to 23, the level at the centre of the site, unless precautions were taken. It treated space workers as a separate case with much higher exposure. | VC07, XC01 | T3 | HIGH |
| CLM-0037 | In its unaudited accounts for 2025, the holding company behind the CASSIOPeiA design reported net assets of about 1.3 million pounds and 1.07 million pounds of convertible loans, and said it owed about 859,000 pounds to a related investor. | XC02, XC05 | T1 | HIGH |
| CLM-0039 | The 1978 report set the figure to protect radio and navigation systems from a disturbed ionosphere, called the number theoretical and untested, and said experiments were underway. | VC06, XC03 | T3 | HIGH |
| CLM-0042 | The 230 watts per square metre figure applies to one frequency and one design lineage. Japanese designs at a higher frequency allow up to about eight times as much. | VC06, XC02 | T0 | MED |
| CLM-0043 | The study the 1978 reference system cites put the level where the beam may start to disturb the ionosphere at about 20 milliwatts per square centimetre. A July 1978 follow-up predicted 12, give or take a factor of two, for runaway heating, and noted the beam affects the ionosphere less at the higher frequency. | VC06 | T3 | MED |
| CLM-0044 | Every mention of the figure in the whole collection can be traced back to the same 1978 American report, restated at least nine times over 48 years, and no source arrives at it independently. | VC06, XC01 | T0 | HIGH |
| CLM-0045 | The apparent conflict between 12 and 23 was not an error. The underlying study gave a range, and the figure adopted sits near the top of it. | VC06 | T0 | MED |
| CLM-0047 | Heating falls with the square of frequency. In 2007 no ground-based measurement of it was available at gigahertz frequencies, and theoretical estimates at 3 gigahertz said a rise in electron temperature from 200 K to 1000 K in the E layer might occur at 500 watts per square metre. | VC06 | T2 | HIGH |
| CLM-0048 | An international scientific body reviewed the proposed figures, found them ranging from 230 to 1,000 watts per square metre, and chose 300 on health grounds, with 10 at the edge of the receiving site. | VC06, VC07 | T2 | HIGH |
| CLM-0049 | The stated design intent in a 2007 URSI white paper is that the beam would be shaped to fall to 10 watts per square metre by the edge of the receiving site, which the paper gives as the human safety limit in most countries. | VC07, XC01 | T2 | HIGH |
| CLM-0051 | The international radio rules do not recognise wireless power transmission as a service, do not regulate it, and the studies that might change that are aimed at 2031. | XC01 | T1 | HIGH |
| CLM-0052 | Neither wireless power transmission nor space solar power is on the agenda for the 2027 world radio conference. | XC01 | T1 | HIGH |
| CLM-0053 | Power beaming is not a recognised radio service, so no spectrum is expected to be allocated for beaming power from space and no international numeric emission limit applies to it; the general duty not to cause harmful interference to radio services does apply. | XC01 | T1 | HIGH |
| CLM-0054 | None of the seven ITU documents on wireless power transmission that were searched mentions what a power beam does to the ionosphere. | VC06, XC01 | T0 | MED |
| CLM-0057 | There is a formula for the instability threshold. It depends on electron density cubed, electron temperature to the fourth power, and frequency cubed, and it has no single value because it assumes how far the beam travels while the instability grows. | VC06 | T2 | MED |
| CLM-0058 | A 2026 modelling paper finds that a reference space solar power beam stays well below the instability thresholds at both candidate frequencies. | VC06 | T5 | LOW |
| CLM-0059 | The two fields were largely the same people from the 1970s, and papers linking them were still appearing after 1991. | VC06 | T2 | MED |
| CLM-0060 | In 1981 a NASA review panel said the 230 watts per square metre figure rested on an obsolete theory with no experimental support, and made resolving it the top priority. | VC06, XC02 | T3 | HIGH |
| CLM-0061 | The experiments were done. They found heating two or three times stronger than normal, not the tenfold effect predicted, no irregularities forming, and effects far smaller than a solar flare produces naturally. | VC06 | T3 | HIGH |
| CLM-0062 | By 1981 the theory was being revised to a steeper frequency dependence, which would raise the permitted power density. | VC06 | T3 | HIGH |
| CLM-0063 | NASA suggested in 1981 that 550 to 600 watts per square metre might be reasonable, roughly two and a half times the figure still in use, and said the parameter decides the system size and has billions of dollars of cost impact. | VC06, XC02 | T3 | HIGH |
| CLM-0065 | A Raytheon study eight months earlier, by the same authors as the lost memorandum, gave a critical power of 15 milliwatts per square centimetre, said irregularities were possible above 20, and gave a strong likelihood of significant disturbance above 50 to 70. | VC06 | T3 | MED |
| CLM-0066 | The figure adopted in 1978 was higher than each of the lower figures in the studies it cited, though those figures were themselves uncertain by up to a factor of two. | VC06, XC02 | T0 | HIGH |
| CLM-0067 | According to a 2007 international report, Japanese designs of the time chose their beam strength on cost and land grounds; the report does not give the ionosphere as the reason. | VC06, VC07, XC02 | T2 | HIGH |
| CLM-0069 | The runaway threshold barely changes with atmospheric conditions. It is decided by the choice of frequency, not by the state of the atmosphere. | VC06 | T0 | MED |
| CLM-0072 | The 1978 study gives 12 milliwatts per square centimetre for runaway, give or take a factor of two, and says no threshold can be set in the usual way for the self-focusing effect, though its summary repeats an earlier study's figure of 20 for it. | VC06 | T3 | HIGH |
| CLM-0075 | When ESA revisited the question in 2004 it used the 1978 theory and did not cite the 1979-81 Platteville tests or NASA's 1981 revision of the figure. | VC06 | T2 | HIGH |
| CLM-0076 | The 1980 programme report says the three-year programme was due to end in 1980, that the heating experiments still needed data to confirm them, and names no follow-on experiment. It offers its findings as a basis for a policy decision rather than making one. | VC06 | T0 | MED |
| CLM-0079 | The 1978 paper modelled both a ground facility and a satellite case, and its 500 watts per square metre figure is a power flux for a given temperature rise, not a power rating. | VC06 | T2 | MED |
| CLM-0081 | The ten-and-a-half order range assumed density and temperature vary independently. They probably do not, which means the real range is narrower. | VC06 | T0 | MED |
| CLM-0082 | The formula is the right one for the conditions space solar power would create. It was written for this case, not borrowed from a different one. | VC06 | T3 | HIGH |
| CLM-0083 | The formula is the right type but nobody has said how far it can be pushed, and at space solar power frequencies the wave is about 200 times the plasma frequency. The field's own 2007 review says the case is unclear. | VC06 | T3 | HIGH |
| CLM-0085 | The 1978 formula does not give a threshold. It relates threshold power to the width of the plasma structures produced, so getting a single number out of it requires deciding which width matters. | VC06 | T0 | HIGH |
| CLM-0087 | The biggest thing deciding this threshold is a human choice about which plasma structure size matters. The choice of radio frequency matters least. The two atmospheric terms are upper bounds, not clean figures, because they were varied independently when they are actually linked. | VC06, XC02 | T0 | HIGH |
| CLM-0088 | The published abstract of the original paper states a testable condition for whether self-focusing can happen at all, and gives the growth length as 25 km in the upper ionosphere and 1 km lower down. Its formulas are set at 15 MHz and carry two factors the abstract does not explain. | VC06 | T1 | HIGH |
| CLM-0089 | Self-focusing can only happen when the ionosphere is dense enough. At 2.45 GHz, with an assumed growth length of 25 km, that means roughly the denser half of modelled conditions in the upper ionosphere. In the lower ionosphere it cannot happen at all. | VC06 | T0 | MED |
| CLM-0092 | Duncan's own 1980 paper says the flawed earlier calculation was Holway and Meltz's, and praises Perkins and Roble's as the first thorough one. It does not say Perkins and Roble were wrong. | VC06 | T3 | MED |
| CLM-0093 | The thousand-fold disagreement between the two published versions was a lost micro prefix in the abstract I was working from. The papers agree. | VC06 | T0 | HIGH |
| CLM-0095 | My earlier duty-cycle figures were percentages of a filtered subset, not of all measured conditions, but were written as though they were of all conditions. The correct all-conditions figures are 23.8 per cent and 1.5 per cent, not 38.5 and 4.9. | VC06 | T0 | HIGH |
| CLM-0096 | Using mid-latitude radar measurements rather than sub-auroral ones, a 230 watt per square metre beam is over the self-focusing threshold in about 11 per cent of measured conditions at 2.45 gigahertz and about 4.5 per cent at 5.8 gigahertz, from four days of data. | VC06 | T0 | MED |
| CLM-0098 | Moving to 5.8 gigahertz helps much less at the mid-latitude radar site measured (Millstone Hill) than at the high-latitude one (Sondrestrom), and by one reasonable measure it is worse there. | VC06 | T0 | MED |
| CLM-0101 | The 1978 contract required the researchers to report fixes if ionospheric disturbance pushed the pilot-beam phase error past 2 to 3 degrees, and a 1981 NASA report allowed 10 degrees of phase error for the whole pointing system. The requirement to hit the receiver within about 300 metres from geostationary orbit was stated in 2007, not in the 1978 design, which left that number open. | VC06, VC07 | T3 | MED |
| CLM-0102 | A 1979 field test found no heating effect on the two navigation systems tested, but did find cross-modulation on time-signal stations and on one AM radio station. | VC06, XC01 | T3 | MED |
| CLM-0103 | Solar flares during the same campaign disturbed the same navigation signals far more than any effect that could be put down to the heater, which was too small to detect. | VC06, XC01 | T3 | MED |
| CLM-0104 | A separate Japanese review worked out the same threshold from the original paper and got 32 and 425 watts per square metre. My own calculation gives 32.01 and 424.73. That is an independent check on the coefficient everything here depends on. | VC06 | T2 | HIGH |
| CLM-0105 | A third party looked at the 230 watt per square metre design figure and said self-focusing may happen at 2.45 gigahertz but not at 5.8 gigahertz. | VC06, VC07 | T2 | HIGH |
| CLM-0106 | Self-focusing has actually been seen in experiments, at Arecibo and at HAARP, not just calculated. | VC06 | T1 | MED |
| CLM-0108 | A 2004 ESA review found that during the October 2003 solar storm, just under 20 per cent of a space solar power beam would have been absorbed before reaching the ground. In quiet conditions the loss is under 0.3 per cent. | VC06, VC07 | T3 | HIGH |
| CLM-0109 | In normal conditions the ionosphere takes essentially none of the beam. In a severe solar storm it could take a little under a fifth of it. | VC06, VC07 | T0 | MED |
| CLM-0111 | An authoritative 2013 review says the 230 watt per square metre figure was chosen early in the design as a cautious maximum. It does not describe it as a measured or derived limit. | VC05, VC06 | T2 | HIGH |
| CLM-0112 | The same review says modern work finds about 1 kilowatt per square metre acceptable at 5.8 gigahertz, more than four times the older figure, and that commercial designs assume it. | VC05, VC06 | T2 | MED |
| CLM-0113 | As of 2013 the experiment needed to check these predictions had still not been done. | VC06, XC01 | T2 | HIGH |
| CLM-0114 | The Russian treatment says self-focusing is triggered by lumpiness already present in the ionosphere, not by beam power crossing a line. That lumpiness is almost always there, so in practice the threshold nearly always is met. | VC06 | T2 | MED |
| CLM-0115 | The Russian and American researchers were talking to each other from at least 1974, so they are not two fully independent traditions. | VC06 | T2 | HIGH |
| CLM-0116 | The Russian formulas are a different shape from the 0.43 relation, so they cannot be used to check it either way. | VC06 | T0 | MED |
| CLM-0118 | Storms big enough to disturb the ionosphere over the UK happen on roughly 12 to 18 days a year on average, mostly around solar maximum. Which figure is right is not yet known. | VC09, XC02 | T3 | LOW |
| CLM-0120 | There is still no international radio allocation for beaming power from space, and the studies are not due until 2031. | XC01 | T1 | HIGH |
| CLM-0123 | NASA's own 2024 study puts space solar power at 12 to 80 times the cost it expects in 2050 from power stations on the ground, a set it calls renewable but which includes nuclear, with launch the dominant cost. | XC02 | T3 | HIGH |
| CLM-0124 | NASA also found that if several things improve at once, rather than just one, space solar power does become cost competitive. | XC02 | T3 | HIGH |
| CLM-0125 | On carbon, NASA found space solar power within the range of five renewable ways of making power on the ground (wind, solar, solar thermal, hydro and geothermal), and far better than coal or gas. NASA also counted nuclear power in that group, though nuclear is not renewable; it sits at the low end, level with wind. | XC03 | T3 | HIGH |
| CLM-0126 | The 1982 source behind the disputed 10 per cent absorption figure actually says absorption is 0.002 per cent, and never mentions solar activity at all. | VC06, VC07 | T3 | HIGH |
| CLM-0128 | A 2013 review gives three references for the 1 kilowatt per square metre figure: two Japanese papers from 1995 and 1996, and a 1981 paper by Perkins and Goldman. | VC06 | T2 | HIGH |
| CLM-0130 | The quiet-condition absorption figures from four sources do not disagree. One of them states an upper bound and the others sit inside it. | VC06 | T5 | HIGH |
| CLM-0131 | Even the most extreme kind of sudden, lightning-caused heating of the upper atmosphere considered in this 2004 study would only block about 3% of a space solar power beam, at most. | VC06 | T2 | MED |
| CLM-0132 | A 1978 NASA-funded study calculated that a beam of about 12 milliwatts per square centimetre at 2.45 GHz would be the point where the ionosphere starts heating itself out of control. | VC06 | T3 | MED |
| CLM-0133 | A 2013 review paper says calculations suggest a stronger microwave beam than the usual safety limit would still be fine at a higher frequency, but the paper itself says these predictions still need to be fully checked in space experiments. | VC06 | T2 | MED |
| CLM-0137 | In four major space solar power studies from 1978 to 2007, none put a number on how much of the beam's energy would be lost if the beam sets up fine stripes of uneven density in the upper atmosphere; they mention the concern but do not measure or calculate it. | VC06 | T3 | MED |
| CLM-0138 | The original 1978 government design for beaming power down from space adds up all the expected energy losses to get 63% overall efficiency, but the list of losses does not include any allowance for the upper atmosphere scattering the beam. | VC05, VC06 | T3 | MED |
| CLM-0139 | Real measurements at the Arecibo Observatory in 1980, in the same physical regime relevant to space solar power beams, found electron density varying by about 2%, occasionally up to 4%, inside large patches of disturbance that formed during high-power radio heating; the authors could not say whether the heating caused them. | VC06 | T3 | MED |
| CLM-0141 | A Chinese government-linked design study calculated that, outside the main beam of its proposed satellite, stray sidelobe power on the ground would fall to about 22 watts and then 7.5 watts per square metre. | VC05, VC06 | T2 | MED |
| CLM-0142 | A major Chinese government-linked design paper on a specific space solar power concept does not mention the upper atmosphere at all, and does not reference any of the classic Western physics papers on beam-ionosphere interaction. | VC06 | T2 | MED |
| CLM-0144 | A NASA study found that launching everything into space is by far the biggest cost of a space solar power system, and that most of those launches would just be carrying fuel to move earlier payloads from a low orbit up to the final, much higher orbit, not carrying useful hardware. | VC10, XC02 | T3 | HIGH |
| CLM-0146 | A 1975 Soviet theory paper calculated an exact minimum radio-wave strength - about 300 millivolts per metre in daytime, ten times less at night - below which a specific kind of upper-atmosphere plasma instability simply does not start. | VC06 | T2 | MED |
| CLM-0147 | A major 2007 physics review gives a different mathematical formula, with different dependence on temperature and frequency and no dependence at all on plasma density, for a related but distinct instability than the one usually used to set space solar power's safety threshold. | VC06 | T2 | MED |
| CLM-0149 | A 1982 Japanese government radio-research review says the famous 230 watts-per-square-metre figure was only ever a theoretical calculation from the 1978 US design study, and had never actually been tested by 1982. | VC06 | T3 | MED |
| CLM-0150 | A 1982 Japanese review notes that, at the time, the American and Soviet safety limits for microwave exposure were far apart (1000 times, by our arithmetic), and that the proposed space solar power design's own human-safety figure was ten times stricter than the US limit of that era. | VC06, XC01 | T3 | MED |
| CLM-0152 | Two UK industry planning documents, from 2022 and 2025, each state a beam-intensity design figure in the 230-245 watts-per-square-metre range, but neither traces that number back to any official safety or interference standard: the 2022 report gives no source for its figure, and the 2025 report, for a system planned to launch in 2033, cites only an earlier internal Frazer-Nash report. | VC06, XC01 | T4 | MED |
| CLM-0153 | A 1980 US government environmental assessment argues, without a formal calculation or test, that an aeroplane's metal body would shield passengers from most of a space solar power beam's intensity if the aircraft flew through it. | VC06, XC01 | T3 | MED |
| CLM-0154 | A 2004 study using seven years of real radio-wave-absorption measurements from northern Finland found a rough mathematical relationship between geomagnetic storm strength and radio absorption, but the relationship only weakly predicts what actually happens on any given day. | VC06 | T1 | MED |
| CLM-0155 | A calculation from existing UK magnetic-field data shows the UK sits just inside the zone where NOAA says a strong (G3-level or worse) geomagnetic storm's aurora becomes visible, and right on the edge of where a moderate (G2) storm's aurora would be seen. | VC06 | T0 | MED |
| CLM-0157 | The published abstract of a 1981 physics paper on self-focusing gives its threshold formulas scaled to 15 MHz, about 160 times lower than the 2.45 GHz often planned for space solar power, and shows no example at gigahertz frequencies. | VC06 | T2 | MED |
| CLM-0158 | Neither of the two sources read at the page, a 2004 review by Robinson and others and Gurevich (2007), states the range of conditions under which this 1981 low-frequency theory is valid at the much higher microwave frequencies space solar power plans to use; the 2004 review applies a similar formula at 2.48 and 5.8 gigahertz without stating one. | VC06 | T3 | MED |
| CLM-0160 | A 1978-81 NASA design study calculated that simply pointing the satellite's structure accurately enough, without any electronic correction, would miss the ground target by 10 to 30 kilometres - which is why the system needs a self-correcting radio-steering mechanism, and that mechanism's own error budget keeps beam losses under 3% and keeps the beam within a quarter of a kilometre of its target 99% of the time. | VC05 | T3 | MED |
| CLM-0161 | Satellite-link observations show that natural disturbances in the upper atmosphere can make a 2.48 GHz radio signal's strength swing by close to 100%; these disturbances are worst near the equator and the poles, and Western Europe is less affected except in rare severe conditions. | VC06 | T3 | MED |
| CLM-0163 | On the exact same navigation-radio circuits used to test simulated space-solar-power heating of the upper atmosphere, a single ordinary solar flare produced a signal disturbance several times larger than anything the simulated heating produced. | VC06, XC03 | T3 | MED |
| CLM-0164 | Two international radio-regulation reports and a radio-science white paper on beaming power from space never mention GPS-type satellite navigation in connection with heating the upper atmosphere, and none of them gives a figure in metres for how far off such navigation could be thrown. | VC06, XC03 | T2 | MED |
| CLM-0165 | A search for other, independent scientific papers that might confirm or challenge the well-known formula used to set space solar power's self-focusing safety threshold found none that actually give a comparable formula to check it against - and the papers most likely to have one could not be accessed at all. | VC06 | T2 | MED |
| CLM-0166 | A 2007 physics paper builds on an earlier, different Perkins paper - not the one usually cited for space solar power's safety threshold - and points out what it says is a genuine mistake in a 1993 paper's mathematics. | VC06 | T2 | MED |
| CLM-0167 | A 2002 computer simulation, done because of two Japanese space-solar-power rocket experiments, modelled a different kind of plasma instability from the "self-focusing" usually discussed, and found its growth rate scales with the beam's strength. To keep the computing time down it ran at a frequency ratio far from a real microwave beam's. | VC06 | T2 | MED |
| CLM-0168 | In this 2008 Japanese review, the absorption figures of under 1% normally and up to about 10% at increased solar activity are not tied to any radio frequency, in their section or in the citation line for their source. | VC06 | T2 | MED |
| CLM-0169 | The 2008 Japanese review that gives the well-known 32 and 425 watts-per-square-metre self-focusing thresholds only ever says self-focusing "might" happen at the lower frequency and is "thought" not to happen at the higher one - it never states either outcome as a settled fact. | VC06 | T2 | MED |
| CLM-0170 | A UK government-commissioned study estimates the cost of electricity from a mature (fifth-built) space solar power satellite at roughly 3.5 to 7.9 pence per kWh in 2018 money, but this swings by almost 3x depending on how much it costs to launch things into orbit. | XC02 | T4 | HIGH |
| CLM-0171 | The same model shows the cost of electricity is noticeably higher for the first unit built than for the fifth, and when this study compares its solar-power-satellite cost to wind and solar costs, those comparator figures do not include the cost of storing or backing up wind and solar power, so it is not a fully like-for-like comparison. | XC02 | T4 | HIGH |
| CLM-0172 | The study uses a high assumed rate of return (20%) to work out the headline cost-per-unit-of-electricity figure, but uses a much lower official government rate (3.5%) when working out whether the whole programme is worth public money - these are not the same number and should not be confused. | XC02 | T4 | HIGH |
| CLM-0173 | Developing a working space solar power system for the UK is estimated to cost somewhere between about 7.5 and 16 billion pounds (in 2021 prices on the report's own statement for this table) over 18 years, with the higher number reflecting a standard government allowance for cost overruns. | XC02 | T4 | HIGH |
| CLM-0174 | On the study's own numbers, a first space solar power system would not, by itself, earn investors the return they would expect (20%) - it would need the UK government to fund roughly half, or more than three-quarters once normal cost overruns are allowed for, of the development cost before private money would follow. | XC02 | T4 | HIGH |
| CLM-0175 | For every pound of public money put into the whole programme, the study estimates the UK economy gets back between GBP 1.30 and GBP 1.80. It counts only the publicly funded share of spending, and values wider economic activity rather than just electricity sold. | XC02 | T4 | MED |
| CLM-0176 | The launch-cost range that drives most of this study's cost uncertainty is not based on any launch that has actually happened - for Starship, a rocket not yet in service, it assumes a launch costs about the same as a Falcon Heavy launch did in 2021 (100 million US dollars), and it also uses a British spaceplane concept (SABRE) that has never flown. | VC10 | T4 | HIGH |
| CLM-0177 | The cost model assumes the satellite gets cheaper to build the more of them are made, using a range that runs from the faster cost-learning of a 2010s space-industry estimate (Mankins) down to the slower cost-learning the study estimates for SpaceX's Starlink constellation; separately, it assumes the system generates power 100% of the time with zero downtime, which the study's own authors call optimistic. | XC02 | T4 | HIGH |
| CLM-0178 | The UK government's own summary of this study repeats the same headline figures as the underlying technical report: about 5 pence per kWh, a development cost of around 16 billion pounds, and an estimated 1.80 pounds of wider economic benefit for every pound spent. | XC02 | T4 | HIGH |
| CLM-0179 | This 2025 paper's own numbers show that with today's technology, their space solar power design would cost about $7.78 per kWh - far more expensive than any terrestrial option - and only becomes competitive (9.4 cents/kWh) if 10 years of assumed technology improvement and cost learning happen first. | XC02 | T2 | HIGH |
| CLM-0180 | The low headline cost figure in this paper depends on using a very low 2% discount rate borrowed from a US home-energy-efficiency programme, not a rate reflecting the financial risk of building a brand-new kind of space infrastructure - the authors themselves flag that a different, riskier financing situation would need a different (higher) rate. | XC02 | T2 | HIGH |
| CLM-0181 | The 9.4-cents and 3.8-cents per kWh figures both depend on launch prices that do not exist yet - they are extrapolated 10 and 20 years into the future from a historical cost-decline trend, using SpaceX's not-yet-finalised Starship costs and a design still based on today's Falcon 9 hardware costs. | VC10 | T2 | MED |
| CLM-0182 | When two different research teams assessed the exact same 1978 space solar power design, the older accounting method (which spreads emissions across whole economic sectors) found about 20 grams of CO2 per kWh, while a newer, more detailed method that traces actual physical processes found 5 to 6 times more - showing that the choice of carbon-accounting method and what it covers can swing a headline SBSP carbon number by a factor of five or six. | XC03 | T5 | MED |
| CLM-0184 | This study's headline carbon-per-kWh figure for a UK space solar power programme leaves out the possible climate effect of soot and aluminium oxide particles released high in the atmosphere by rocket launches, because the science on that effect is still too uncertain to model - and the authors say this gap is normal for this type of study, not unique to theirs. | XC03 | T2 | HIGH |
| CLM-0185 | In a 2022 life-cycle study commissioned by the UK Space Energy Initiative, the lightweight CASSIOPeiA design it used as an example for the initiative's planned programme was estimated to be far cleaner per kWh than the old, heavy NASA/DOE design, and in the same broad range as wind and solar on this measure, though above nuclear's 5.1-6.4 range - but the same study found that almost all of a completely different, non-carbon environmental impact (ozone depletion) came from rocket exhaust during launch. | XC03 | T2 | MED |
| CLM-0187 | The company's own 2024 analysis estimates that a single, non-reused Starship launch to low orbit would cost about $665 per kilogram, and projects (using two very different learning-rate scenarios) that this could fall to somewhere between about $12 and $614 per kilogram within ten years, with the company itself expecting something close to $500/kg. | VC10 | T4 | MED |
| CLM-0188 | A 2012 NASA-funded concept study shows its own cost estimate falling from about $3.26 per kWh for a small near-term system down to about 9 cents per kWh for a much bigger system built with assumed future technology improvements - and the author states plainly that this headline low figure is only an early-stage estimate ("TRL 3"), not a validated cost. | XC02 | T3 | LOW |
| CLM-0189 | A separate 2022 study for the European Space Agency, by Frazer-Nash and London Economics, estimates the cost of electricity from a first full-scale unit, with investors expecting a 20% return, at between about 11 and 21 euro cents per kWh, and notes that if launch costs could reach levels already being observed for reusable NASA/SpaceX flights (about 400 euros per kg), the technology would become genuinely competitive. | XC02 | T4 | HIGH |
| CLM-0190 | This European study finds that a full Europe-wide space solar power programme would cost about 418 billion euros in today's money but return about 600 billion euros in benefits once the value of avoided fossil fuel generation, avoided CO2 emissions and R&D spillovers are all counted - a net benefit of roughly 150 to 260 billion euros depending on assumptions, and a net loss of about 171 billion euros if all its costs doubled. The value put on avoided CO2 emissions (about 233 billion euros) is larger than the whole net benefit, so the result rests on that valuation rather than on the electricity itself. | XC02 | T4 | HIGH |
| CLM-0191 | This 2022 report is one of two parallel studies the European Space Agency commissioned on the costs and benefits of space solar power: this one used the CASSIOPeiA design and was done by Frazer-Nash with London Economics; the report says the other, by Roland Berger and OHB on a different design, was done independently. | XC02 | T4 | HIGH |
| CLM-0192 | The full list of assumptions behind the headline result of NASA's 2024 study, that space solar power would cost far more than ground alternatives, includes a launch cost of $850-1,000 per kilogram, only a 10-year satellite lifetime, and a solar cell efficiency of 35% - each of these, not just launch cost, is doing some of the work in producing the high headline cost figure. | XC02, XC03 | T3 | HIGH |
| CLM-0193 | To get to a competitive cost, NASA's own 2024 analysis needs launch costs to halve, solar cells to get much more efficient, satellites to last half as long again, and manufacturing to get cheaper faster, all at the same time, not just one improvement on its own; and there is a small but real inconsistency inside the NASA report itself about exactly how low the resulting cost estimate for the smaller design (RD1) is - Table 3 says 4 cents per kWh, the summary text says 3 cents. | XC02, XC03 | T3 | HIGH |
| CLM-0194 | This 2010 paper predicts that if enough solar power satellites were built to justify mass-producing reusable rockets, launch could eventually cost around USD 400-450 per kilogram, against over USD 10,000 per kilogram at the time of writing, and this would add only about 2 US cents per kilowatt-hour to the price of the electricity produced. | VC10, XC02 | T5 | MED |
| CLM-0195 | In 2025 the whole world launched about 2,712 metric tons of satellites into orbit across 325 launches. A single 2010-era plan for solar power satellites assumed that, at its busiest point, over 160,000 metric tons a year and thousands of launches a year would be needed just for that one program. Real-world 2025 launch activity is far below that assumed scale. | VC10, XC02 | T5 | MED |
| CLM-0198 | The same 2010 paper gives two very different price tags, about $650 million and about $5 billion, for storing the same amount of electricity (26 gigawatt-hours, about one day's supply for a city the size of Austin, Texas). The paper does not explain why the two numbers differ. | VC09, XC02 | T5 | HIGH |
| CLM-0199 | The paper estimates that just launching the parts for a 1-gigawatt space solar power satellite would cost at least $25 billion, using 2010-era, pre-reusable-rocket launch prices scaled up from the Ariane V rocket. The author calls this launch cost alone "uneconomic." Adding the cost of building the satellite and the ground antenna brings the total to about $30 billion per gigawatt, which is far above the $1-5 billion per gigawatt the paper cites for building a new fossil-fuel or nuclear power plant. | VC10, XC02 | T5 | HIGH |
| CLM-0200 | A new solar cell design, tested only in computer models, is predicted to convert more than 25% of sunlight to electricity in orbit. | VC01 | T2 | MED |
| CLM-0202 | In simulation, this new cell design can produce a strong 1 kW per square metre of power while staying at a moderate 50 degrees C. | VC01 | T2 | MED |
| CLM-0204 | In this 1978 design, heat from the power-conversion tubes, not the RF electronics themselves, set the top limit on how much power the transmitting antenna could handle per square metre. | VC03, VC05 | T3 | HIGH |
| CLM-0206 | The heat-management equipment on the transmitting antenna alone was expected to weigh about 2,500 tonnes, roughly one-twelfth of the whole satellite's dry weight. | VC03 | T3 | HIGH |
| CLM-0210 | A 1978 US government design for a solar power satellite planned to move its power around at 40,000 volts DC because it judged that this would save weight compared with AC, but the same report lists the high-voltage DC switches and cable insulation needed to do this as still to be developed. | VC02 | T3 | HIGH |
| CLM-0211 | The 1978 design includes a small backup battery, but its only job is to keep the microwave tubes' heaters warm during the brief periods each year when the Earth blocks the sun from the satellite. It is not a battery for storing the satellite's main power output. | VC02 | T3 | HIGH |
| CLM-0212 | In the 1978 design, the equipment that moves and controls electrical power on board makes up about one fifth of the satellite's total dry weight. | VC02 | T3 | HIGH |
| CLM-0213 | The study assumes that connecting a ground receiving site to the electricity grid costs about GBP 150,000 for every megawatt of power the site handles. | VC08 | T4 | HIGH |
| CLM-0214 | Six different solar-power-satellite designs each claim that turning the electricity collected on the ground into grid-ready power is 90 to 99% efficient, but nobody has independently checked these numbers. | VC08 | T4 | HIGH |
| CLM-0215 | Any UK ground receiving station that wants to connect to the electricity grid must be able to supply or absorb a type of power called reactive power, under an existing UK grid rule. | VC08 | T4 | HIGH |
| CLM-0216 | The UK's fast-response grid support services need a generator to react within seconds, at any moment over a 4-hour period. A ground receiving station on its own could not promise that, so it would need its own battery to offer this kind of service. | VC08 | T4 | HIGH |
| CLM-0230 | A 2019 US study warns that large solar power satellites could be more at risk as more countries build anti-satellite weapons, and suggests using many small satellites instead of one big one to reduce that risk. | XC04 | T3 | MED |
| CLM-0232 | Some of the radio frequencies being considered for beaming power down from space are the same frequencies already used by military airfield equipment worldwide, which makes it harder to pick a site. | XC04 | T3 | HIGH |
| CLM-0235 | A 2020 UK study rated the UK behind other countries in many technologies for a solar power satellite. For three key ones, large mirrors, space solar panels and power beaming, it named the UK's lack of manufacturing experience or capacity as the main barrier. It rated closing these three gaps by 2050 as medium to very high difficulty, depending on the technology. | VC04, XC05 | T4 | HIGH |
| CLM-0236 | In 2025, all the rockets launched by every country and company in the world together put about 2.7 million kilograms of satellites into orbit, and one company (SpaceX) launched most of them. | XC05 | T2 | HIGH |
| CLM-0240 | A from-scratch cost model of the "Innovative Heliostat Swarm" design gets almost the same electricity cost as NASA's own study: about 62 cents per kWh versus their 61 cents. | XC02 | T0 | HIGH |
| CLM-0241 | For the "Mature Planar Array" design, an independent cost model built the same way as for the other design gets a materially lower electricity cost than NASA's published figure, even though the underlying costs match closely. | XC02 | T0 | MED |
| CLM-0242 | Working the power output out from scratch, using only the physics of sunlight and the efficiency losses NASA itself lists, gives the same answer NASA published. | XC02 | T0 | HIGH |
| CLM-0243 | The huge number of rocket launches NASA calculated for each design can be rebuilt from scratch using just the mass of the hardware, how much a rocket can carry, and how many refuelling trips each delivery needs -- and it comes out almost exactly the same. | XC02 | T0 | HIGH |
| CLM-0246 | Adding up the costs from scratch -- rockets, factories, spare parts -- gives almost exactly the same total bill NASA calculated, for both designs. | XC02 | T0 | HIGH |
| CLM-0247 | NASA's published cost figure for the "Mature Planar Array" design may be counting the effect of its low duty cycle twice by mistake, which would make the true figure closer to 1.0 dollars per kWh rather than 1.59. | XC02 | T0 | MED |
| CLM-0248 | How fast the cost of building each solar-power-satellite module falls as more are made turns out to matter more to the final electricity price than the cost of getting them into orbit -- more than any other single thing tested in this model. | XC02 | T0 | MED |
| CLM-0249 | Simply choosing a different interest rate to value future costs and income changes the final electricity price about as much as most of the technical improvements NASA tested -- and NASA never actually tested this choice. | XC02 | T0 | HIGH |
| CLM-0250 | If the design that runs almost all the time had to operate at the same lower duty cycle as the other design, its electricity cost would rise by about two-thirds, all on its own. | XC02 | T0 | MED |
| CLM-0256 | If several other improvements happen together -- better propulsion, much better solar cells, faster manufacturing learning, and hardware that lasts 15 to 20 years -- then a launch price of roughly 15-30 million dollars per flight would be enough to bring this design's electricity down to about 5 US cents a kilowatt hour. For 2050 NASA projects about 2 to 5 cents for five renewable sources on the ground (wind and solar with storage about 2 cents; geothermal, hydro and solar thermal about 5) and about 5 cents for nuclear, which NASA counts with them though it is not renewable. So 5 cents matches the dearest of these, not the cheapest. | XC02 | T0 | MED |
| CLM-0257 | For every kilogram of hardware launched into orbit over the station's 30-year life, RD1 generates about 30,000 kilowatt-hours of electricity, and RD2 about 17,500. | XC02 | T0 | MED |
| CLM-0258 | Every dollar amount in this document is priced as if it were 2022, matching NASA's own report; nothing has been adjusted for inflation to today's prices. | XC02 | T0 | HIGH |
| CLM-0259 | Building the cost model completely independently still leads to the same overall conclusion NASA reached: today's space-based solar power concepts cost far more than the electricity NASA projects for 2050 from five renewable sources on the ground and from nuclear (about 2 to 5 cents a kilowatt hour), and no single fix closes that gap on its own. | XC02 | T0 | HIGH |
| CLM-0260 | A U.S. government-linked cost model (formerly NREL, now called the National Laboratory of the Rockies) estimates that plain utility-scale solar power could cost between about 14 and 56 US dollars per megawatt-hour by 2030-2050, depending how fast costs fall and how good the sunlight is at the site. Adding four hours of battery storage to smooth output raises this to about 25-113 dollars per megawatt-hour. These figures do not include the cost of storage large enough to cover a full day or night, so they are not a "24-hour power" cost. | XC02 | T3 | HIGH |
| CLM-0261 | The same U.S. cost model estimates onshore wind power at roughly 16-73 US dollars per megawatt-hour by 2030-2050, and offshore wind at a much wider 42-460 dollars per megawatt-hour, depending on cost-case assumptions and how good the wind resource is at the site. The high end of the offshore wind range reflects a poor wind site and a pessimistic cost case; it is not a typical or recommended figure. | XC02 | T3 | HIGH |
| CLM-0263 | A widely used financial-industry cost report estimates 2026 U.S. power costs, without subsidy, as follows: utility solar 40-98 dollars per megawatt-hour, onshore wind 37-99, offshore wind 105-167, new gas power plants 51-129 (combined-cycle) or 144-276 (fast-response peaker plants), new nuclear 175-255, and new coal 72-177. These are today's costs only; the report does not attempt to project what these costs will be in future decades. | XC02 | T4 | HIGH |
| CLM-0265 | The same report assumes, by default, that a power project is financed 60 percent by debt (at 8 percent interest) and 40 percent by equity investors (who require a 12 percent return), giving a combined after-tax financing cost of about 7.7 percent. It also shows, separately, what happens if that financing cost is higher or lower, from as low as 4.2 percent to as high as 10.0 percent: at the low end, a typical utility solar project costs about 71 dollars per megawatt-hour; at the high end, about 106 dollars. Financing cost matters a lot for a technology like solar or nuclear that is very capital-intensive up front. | XC02 | T4 | HIGH |
| CLM-0266 | The report itself warns that its main headline cost figures leave out the wider costs of running a reliable power grid, things like power lines, backup capacity, and keeping the system balanced. It also says clearly that it is not trying to predict what power will cost in future years, and that it should not be read as the full cost of supplying electricity to a system, only the cost of building and running one project. This warning matters directly for any comparison against a claim about future, for example 2050, power costs, or against a source that assumes the wider grid costs are already included. | XC02 | T4 | HIGH |
| CLM-0267 | In 2025, IRENA estimated that new solar power around the world cost about 4.4 US cents per kilowatt hour on average, and onshore wind about 3.3 cents. Other renewables cost more. Each figure is the cost of that technology on its own. | XC02 | T3 | HIGH |
| CLM-0268 | In 2023, IRENA estimated that new onshore wind farms in Europe cost about 4.6 US cents per unit of electricity on average, and new offshore wind farms in Europe cost about 6.7 cents. For the UK specifically, IRENA gives a slightly lower offshore wind figure of about 5.9 cents per unit. These do not include storage or balancing cost. | XC02 | T3 | HIGH |
| CLM-0269 | In 2025, IRENA put the cost of building a large battery that can supply power for four hours at about 140 US dollars per kilowatt hour of storage. That is nearly 30 per cent less than a year earlier and about a twentieth of the 2010 cost. | XC02 | T3 | HIGH |
| CLM-0270 | DESNZ estimated in its 2025 report that a new large solar farm built in the UK and commissioned in 2030 would generate power at about 60 pounds per megawatt-hour (6 pence per kilowatt-hour), and one commissioned in 2050 at about 49 pounds. Onshore wind is estimated at a similar cost; offshore wind is estimated at roughly double the cost of solar or onshore wind. These figures do not include the cost of storing power or balancing the grid. | XC02 | T3 | HIGH |
| CLM-0271 | DESNZ estimated that a new gas power station in the UK, run almost continuously, would generate power at about 111-112 pounds per megawatt-hour (about 11 pence per kilowatt-hour), whether commissioned in 2030 or 2050. A gas plant with carbon capture, run the same way, is estimated slightly cheaper. These are the closest dispatchable, always-available comparators in this report; they are gas-fired, not firmed renewables. | XC02 | T3 | HIGH |
| CLM-0272 | The UK government's 2025 cost report does not give a single number for what it would cost to make solar or wind power available around the clock; it says that working this out needs a full power-system model, which this report is not. It also does not publish specific cost figures for the UK's flagship nuclear projects, because those costs are commercially confidential. | XC02 | T3 | HIGH |
| CLM-0276 | The price the UK government agrees to pay offshore wind farms, per unit of electricity actually generated, dropped sharply from 2015 to 2022, then rose again through 2024 and 2026. In 2023 no offshore wind developer was willing to build at the price on offer, so zero megawatts were awarded that year. These are real, dated contract prices from competitive auctions, not projections, but they are for electricity as generated, not for guaranteed firm delivery. | XC02 | T3 | HIGH |
| CLM-0277 | The price the UK government agrees to pay solar farms, per unit of electricity actually generated, has stayed close to 46-50 pounds per megawatt-hour (in fixed 2012-price terms) across the last four auction rounds, from 2022 to 2026. This is a real, dated contract price, not a projection, but it is only paid for electricity as generated, with nothing extra for guaranteed delivery. | XC02 | T3 | HIGH |
| CLM-0278 | The price the UK government agrees to pay onshore wind farms, per unit of electricity actually generated, roughly halved from 2015 to 2022, then rose again through 2024 and 2026. These are real, dated contract prices from competitive auctions, not projections, but they are for electricity as generated, not guaranteed firm delivery. | XC02 | T3 | HIGH |
| CLM-0279 | A few UK renewable-energy auction contracts are for technologies that can generate more steadily than wind or solar: waste-to-energy plants, biomass-with-heat plants, and a handful of small pilot geothermal plants in Cornwall. Their contracted prices, in fixed 2012-price terms, range from about 46 to 119 pounds per megawatt-hour. These are the best real UK price signals in the register for something closer to firm power, but they are all small in scale and none of them carries a formal obligation to deliver on demand. | XC02 | T3 | HIGH |
| CLM-0280 | A 2022 ESA-commissioned study modelled that the first European space solar power satellite could produce electricity at a cost of 106 to 206 euros per megawatt-hour. It modelled that this could fall to about 88 to 156 euros per megawatt-hour once ten similar satellites had been built. | XC02 | T4 | MED |
| CLM-0281 | The study tested how much the cost of launching material into space changes the price of space solar power. It used launch-cost data from about 2022. The report says that if launch costs fell to about 400 euros per kilogram, which it describes as similar to costs seen for reusable SpaceX rockets at the time, space solar power could become highly competitive with other ways of generating electricity. The report does not give a source for the 400 euro figure. | VC10, XC02 | T4 | MED |
| CLM-0282 | A 2022 ESA-commissioned study modelled that, from 2022 to 2070, space solar power for Europe could deliver a net economic benefit of about 183 billion euros, counting avoided costs of building, fuelling and running power plants on the ground, avoided carbon emissions and other benefits. It also modelled that private investors would not fund the first satellite alone unless the government paid for a large share of development: roughly 58 percent if investors need a 20 percent return, or roughly 30 percent if they need a lower 15 percent return. | XC01, XC02 | T4 | MED |
| CLM-0286 | A 2025 peer-reviewed study modelled space solar power inside a detailed model of Europe's future electricity system, using the more favourable of NASA's cost projections for the year 2050, the one that needs several improvements together. It found that one satellite design using mirrors (called RD1) could lower the total cost of Europe's power system by 7 to 15 percent and replace much of the wind and solar power otherwise needed, but only if its projected costs are actually achieved. A second design using flat panels (called RD2) came out too expensive to be worthwhile at its projected 2050 cost. | XC02 | T2 | MED |
| CLM-0287 | In 2023 and 2024, the UK government awarded about GBP 5.5 million in grants to 9 projects to develop space-based solar power technology and components, through a competition that opened in 2022 and was funded by the UK Space Agency and the old BEIS department. These are awards with named recipients and amounts, not just a plan. The government page lists award values; it does not report how much was paid out. | XC01, XC02 | T3 | HIGH |
| CLM-0288 | In 2025, a House of Lords committee looking at UK space policy received written submissions from two space-based-solar-power advocacy organisations, Space Solar and the Space Energy Initiative, asking for more UK government funding and support. The committee published its final report in November 2025, and the government responded in January 2026. | XC01 | T5 | MED |
| CLM-0290 | On 29 May 2025 UKAEA, the UK's national fusion energy research organisation, published a press release saying that it and the company Space Solar had finished a demonstration in which robots assembled a small test section of the kind of structure a solar power satellite would need, part-paid for by a UK research council grant whose amount was not published. We have the press release and nothing else; no independent party has confirmed the demonstration or what it showed. | VC11, XC01, XC05 | T6 | MED |
| CLM-0291 | As of February 2026, the UK government's own webpage on space-based solar power describes the two studies it has paid for and links to its earlier innovation competition. It does not announce any new funding or a plan to build anything. | XC01 | T3 | HIGH |
| CLM-0294 | In December 2024 a Japanese team beamed 5.8 GHz microwaves from a business jet flying at 7,000 metres down to a receiving site about 5 kilometres below, 40 times over four flights, and the measured beam shape matched theory closely. The report gives the strength of the received signal only in decibels, and states no transmitted power, no received electrical power and no efficiency, so it shows that the beam could be formed and aimed at that range, not that any useful amount of power was delivered. | VC05, VC06 | T4 | MED |
| CLM-0296 | A 2025 peer-reviewed study from Caltech modelled its own space solar power design and calculated three costs of electricity: about 778 US cents per kilowatt-hour using today's technology, 9.4 cents after about ten years of development, and 3.8 cents in a long-run best case about twenty years out. The 9.4 cents figure that is often quoted is the middle case, not a present-day cost. The design is small, about 113 megawatts, and converts only about 4 percent of the sunlight it collects into electricity delivered on the ground. | XC02 | T2 | MED |
| CLM-0297 | The low electricity costs in a 2025 Caltech study rest on two assumptions among others. First, it assumes that SpaceX's Starship will in time launch cargo for about 7 million dollars a flight, falling to 3 million, which works out at roughly 128 dollars and then 55 dollars per kilogram. Those are the authors' own projections, built on the way SpaceX said in 2020 that Starship would reach geostationary orbit and on the long-run fall in launch costs, not prices anyone has paid. Second, it assumes that the money to build the system costs 2 percent a year (a 2 percent discount rate), taken from a US government energy memorandum, which the paper itself says reflects one country's funding arrangements at one moment. With the costs and hardware available when it was published in 2025, the same study's own figure is about 778 US cents per kilowatt-hour. | VC10, XC02 | T2 | MED |
| CLM-0300 | The main international definition of LCOE is the flat price per unit of electricity a power plant would need to be paid, every year of its life, to break even overall. | XC02 | T3 | HIGH |
| CLM-0301 | The IEA itself says plain LCOE misses how useful a power plant is to the wider electricity system, which is why it built a second, add-on metric. | VC09, XC02 | T3 | HIGH |
| CLM-0302 | The US government's own energy statistics agency warns that comparing plain LCOE across different kinds of power plant, without also looking at value, can be misleading. | VC09, XC02 | T3 | HIGH |
| CLM-0303 | A major financial advisory firm's own widely-used LCOE report says plainly that its numbers do not cover intermittency or total system cost. | VC09, XC02 | T4 | HIGH |
| CLM-0304 | The interest rate assumed changes an LCOE figure a lot, and most for plants that cost the most to build: in a 2020 international study, going from 0% to 20% raised gas plant costs by about 40%, wind and solar by about three times, and nuclear by more than five times. | XC02 | T3 | HIGH |
| CLM-0305 | How long a power plant is assumed to last matters much less to its cost per unit of electricity than the interest rate does. | XC02 | T3 | HIGH |
| CLM-0307 | The US government's avoided-cost metric shows that, for the power plants it expects to be built, value and cost are within about 25 percent of each other; for some plants it does not expect to be built, such as offshore wind, coal and nuclear, value is half of cost or less. | VC09, XC02 | T3 | HIGH |
| CLM-0308 | The IEA's alternative metric adds credit for how much a power plant helps keep the grid reliable, on top of its raw energy cost, but the IEA itself says the answer depends heavily on what the future electricity system is assumed to look like. | VC09, XC02 | T3 | MED |
| CLM-0309 | One influential academic paper shows that once you add in the extra cost a variable power source creates for the rest of the grid, its true cost to the system can end up roughly double its own sticker price at high market share. | VC09, XC02 | T2 | HIGH |
| CLM-0310 | How much a solar farm can be relied on to replace a conventional power plant, measured properly, drops sharply as more solar is added to the same grid. | VC09, XC02 | T2 | HIGH |
| CLM-0311 | As more wind or solar power is added to a grid, each additional unit of it earns a lower price on average, because it increasingly arrives when everyone else is also generating. | VC09, XC02 | T2 | HIGH |
| CLM-0312 | A major financial advisory firm has estimated, using US grid operators' own published figures, what it adds to the cost of wind or solar to count them as dependable capacity alongside gas power stations; on its figures the addition is between about 8% and 85% of the plant's own cost, not many times more. | VC09, XC02 | T4 | HIGH |
| CLM-0315 | Even though NASA's own figures say space solar power's carbon footprint is about as good as five renewable sources of power on the ground (NASA also counts nuclear with them, though nuclear is not renewable), that similarity means paying extra for space solar power buys almost no additional carbon saving compared with those low-carbon sources - and even compared with gas, the implied price per tonne of carbon saved is extremely high, about 1,250 to 1,400 dollars. | XC02, XC03 | T0 | MED |
| CLM-0316 | In 2009 three researchers guessed that, once the energy to deliver and use it is counted, an oil-based fuel must return at least about 3 times the energy put into it, and a society's main fuels about 5 times, to support modern life; a search found no open, peer-reviewed calculation of where space solar power sits against such thresholds. | XC02 | T3 | MED |
| CLM-0317 | Two studies of how much land US ground-mounted solar farms need, the second drawing most of its measurements from the first, indicate once converted to the same units that the receiving antenna of a space solar power design already in the register would need roughly a quarter to a fifth as much ground per unit of electricity delivered. | XC02, XC03 | T0 | HIGH |
| CLM-0318 | Looking across every different way economists and grid operators actually measure how much extra a reliable power source is worth, it is worth a bit more: up to about four times as much when measured as an average across a grid's solar farms, which stays well short of the 12-to-80-times difference space solar power's own cost study found. Measured as the value of the last solar farm added to a grid already full of solar, it can be much larger, and the study behind that figure gives no upper limit. | VC09, XC02 | T0 | MED |
| CLM-0319 | The register's recommended way to check space solar power's economics against something other than plain cost-per-unit is the IEA's value-adjusted cost, whose formula is now public, checked against a US value-for-money ratio whose underlying figures are published, plus a comparison against an illustrative cost of firm, reliable power in today's electricity markets. | VC09, XC02 | T0 | MED |
| CLM-0331 | Rockwell International's 1978 design study estimated the satellite would need about 93 tonnes of thruster fuel resupplied every year, a very small fraction of its roughly 30,000-tonne mass. | VC04 | T3 | MED |
| CLM-0332 | The 1978 design's steering system used 64 ion thrusters running on argon gas, grouped into eight clusters, to keep the satellite pointed correctly. | VC04 | T3 | MED |
| CLM-0333 | In one 1978 design, structure and mechanisms made up about 18% of the satellite's dry mass; a 2010 paper gives about 20% as a general rule for the main structure of aerospace systems. The two figures measure different things, so they are not two estimates of one share. | VC04 | T5 | MED |
| CLM-0336 | Different design studies over four decades have each simply assumed a different working lifetime for a solar power satellite, from about 15 years to 30 years; none has actually operated one long enough to know which is right. | VC12 | T5 | MED |
| CLM-0337 | The 1978 study expected the satellite's mirrors to lose about a fifth of their reflectivity over 30 years in space, though the same document gives two different numbers for this in two different places. | VC12 | T3 | MED |
| CLM-0338 | The 1978 design assumed each steering thruster would fail on average once every five years, and that its grids would wear out after about 5,000 hours (roughly seven months) of running. It carried 64 thrusters so that spares could cover failures between yearly maintenance visits. | VC04, VC12 | T3 | MED |
| CLM-0339 | A 2019 paper said solar power satellites are often assumed to need visits in orbit for repairs and refuelling, but that no system yet existed to service satellites at geostationary orbit, though one was being developed. | VC11, VC12 | T2 | MED |
| CLM-0343 | A 2010 NASA paper argues that building a solar power satellite in space is not just a robot problem: the module design, the assembly steps, and the supporting equipment all have to be developed together. It suggests starting with a much smaller test system first. | VC11 | T5 | MED |
| CLM-0370 | Converting the UK government's 2021 space solar power cost estimate onto the same money-year, same investment-return and same asset-life basis as the other studies in this comparison gives about 21 to 49 pounds per megawatt-hour, depending on which return rate is used. | XC02 | T0 | MED |
| CLM-0372 | The second 2022 European Space Agency study cannot be fully converted onto the same basis as the others, because it does not say what investment-return rate or satellite lifespan it assumed for the two cost figures used here. Only the currency and inflation adjustment could be done. | XC02 | T0 | LOW |
| CLM-0373 | Rebuilding NASA's 2024 space solar power cost estimate from the ground up, then converting it onto the same basis as the other studies, gives roughly 560 to 1,790 pounds per megawatt-hour depending on which design and which return rate is used -- an order of magnitude above the UK and European studies on the same basis (CLM-0389). | XC02 | T0 | MED |
| CLM-0374 | NASA's own best-case space solar power scenario, if several separate improvements all happen together, converts to roughly 33 to 154 pounds per megawatt-hour on the same basis as the other studies -- broadly similar to the UK and European baseline studies' figures, not to NASA's own baseline figures. | XC02 | T0 | LOW |
| CLM-0375 | Converting Caltech's 2025 space solar power cost estimates onto the same basis as the other studies gives a huge range on its own: from over 2,600 pounds per megawatt-hour using only today's technology, down to about 23 pounds in the paper's most hopeful case, which it describes as what new design and manufacturing advances might make possible in 20 years. | XC02 | T0 | LOW |
| CLM-0377 | Before using a shortcut method to work out how much changing the assumed investment-return rate and satellite lifespan would move each study's cost figure, this calculation checked the shortcut against two real answers it could look up. It matched closely (within about 4%) for a small change, but was off by 10 to 30% for a bigger change, which means the shortcut method is good enough to show the direction and rough size of an effect, but not precise enough to trust its last few percent. | XC02 | T0 | MED |
| CLM-0378 | If every number in this exercise is compared at once, including each study's own best-case and worst-case scenarios, the spread looks even wider than before -- over a hundred times. That is not evidence of new disagreement between institutions; it happens because comparing one study's optimistic best case against another's pessimistic worst case will always look wide, on any subject. | XC02 | T0 | MED |
| CLM-0379 | Once the UK, European and US flagship studies are all put on exactly the same money-year, investment-return and satellite-lifespan basis, comparing like designs to like designs, the gap between the cheapest and most expensive is still about 19 to 37 times -- essentially unchanged from, and in one comparison larger than, the roughly 20 times found before any of this restatement work was done. | XC02 | T0 | MED |
| CLM-0380 | Changing the assumed investment-return rate moves any single study's cost estimate a lot on its own, about four to five times. But the cheapest study in this comparison already uses the harshest rate, and the most expensive study already uses the gentlest one. So making the rates the same does not bring the studies together -- it makes clear that something other than the rate is doing the real work of making one study's numbers so much lower than the other's. | XC02 | T0 | MED |
| CLM-0381 | Two separate UK and European studies of the same satellite design agree that building five to ten of them, instead of just one, cuts the cost of electricity by roughly a fifth to a quarter. That is a real and consistent finding, but it is far too small an effect to explain why different institutions' cost estimates differ by many times over. | XC02 | T0 | MED |
| CLM-0382 | How much it will cost to get one kilogram of hardware into the right orbit is the single biggest unresolved disagreement in this whole comparison. NASA's assumption is actually higher than the UK and European studies' assumptions, even though NASA uses a far gentler investment-return rate that should have let it show a lower cost, not a higher one -- this is the specific mechanism behind why the studies do not agree even after every other adjustment. Separately, a 2025 US paper's more optimistic scenarios assume launch prices about ninety to two hundred times lower than NASA's, based on a 2020 company planning document rather than any price actually paid. | XC02 | T0 | MED |
| CLM-0384 | This exercise could not fully convert every study onto the same basis. One study (Roland Berger/OHB) is missing too many basic facts -- what return rate, what satellite lifespan, what launch cost it assumed -- to be rescaled at all beyond a basic currency conversion. Another (Caltech) required a best-guess stand-in for satellite lifespan. And the exchange rates and inflation figures used throughout are remembered rather than freshly looked up, because internet access was not available for this task. | XC02 | T0 | HIGH |
| CLM-0385 | In order of how much they actually matter: what launch is assumed to cost matters most by far; the choice of investment-return rate matters a lot in isolation but works in the wrong direction to explain why the studies disagree; genuine differences in satellite design matter but cannot be measured precisely from what is available; the size of the satellite probably matters somewhat; building several units instead of one matters a little; and using different currencies and price-years barely matters at all. | XC02 | T0 | MED |
| CLM-0386 | Even after making the money-year, currency, investment-return rate and satellite lifespan identical across the UK, European and US flagship studies, the gap between the cheapest and most expensive stays at roughly twenty to thirty-five times. Most of the apparent disagreement between these institutions is real, not an artefact of how the numbers were prepared, and the single biggest identified reason is that they assume very different prices for getting hardware into orbit. | XC02 | T0 | MED |
| CLM-0387 | Caltech's design is a different, much smaller thing from the UK, European and US flagship studies, so its numbers are kept separate rather than folded into the main size-twenty-to-thirty-five comparison. Its own three cost estimates are still useful, but mainly to show how much assumed future technology and launch-price improvement can move one paper's own numbers, not to compare directly against the bigger designs. | XC02 | T0 | MED |
| CLM-0388 | This is the full list of places where this calculation had to approximate, guess, or simply could not go further, collected in one place so nobody has to hunt through six other records to find them. | XC02 | T0 | HIGH |
| CLM-0389 | The question was how much of the apparent twenty-times disagreement between major space solar power cost studies was real, and how much was just different currencies, price-years, investment-return assumptions and satellite lifespans. The answer is that almost none of it was bookkeeping. Once everything is put on the same footing, NASA's figures, as rebuilt here, are still 19 to 37 times the UK government-commissioned study's, and less far apart from the European study's, and the single biggest reason is that they assume very different prices for getting a kilogram of hardware into orbit. This is a genuine, unresolved disagreement about a real-world cost, not an artefact of how the numbers were reported. | XC02 | T0 | MED |
| CLM-0390 | Putting all the cost estimates on the same footing does not make them agree. The disagreement is real, not an accounting artefact. | XC02 | T0 | MED |
| CLM-0400 | Millstone Hill sits at almost exactly the UK's magnetic dip angle, and the UK's modelled density range fits entirely inside what Millstone Hill measured. So Millstone Hill data can be used for the UK without extrapolating across latitude, though it is not a UK measurement. | VC06 | T0 | HIGH |
| CLM-0401 | A 2004 review calculated that, under some of the most extreme conditions measured during a large solar storm in October 2003, only just over four fifths of a microwave power beam would get through the ionosphere and atmosphere to the ground, against more than 99.7 per cent normally. The storm lasted more than a day, but conditions varied, so a loss that large probably (our inference) did not last throughout. The standard 1978 efficiency figures include no allowance for it. | VC06, VC07, VC09, XC02 | T3 | MED |
| CLM-0405 | A 1994 Japanese article says the numbers behind its 230 figure came from a 1993 Master's thesis, which has not been found in any index searched. | VC06 | T5 | MED |
| CLM-0407 | Cutting the price of a rocket launch brings the electricity cost down to roughly the same low point NASA itself found, using an independently built model. | XC02 | T0 | HIGH |
| CLM-0408 | If the hardware lasted the full 30-year mission without needing to be replaced twice, the electricity cost would fall by almost half, on its own. | XC02 | T0 | HIGH |
| CLM-0410 | Switching from chemical rockets that need refuelling to electric thrusters that do not would cut the electricity cost by about two-thirds, matching what NASA itself found. | XC02 | T0 | MED |
| CLM-0420 | NASA's 1981 report says the experiments found nothing supporting the 23 milliwatt limit, that the measured heating was two or three times, not ten times, and that the theory was being rewritten. Its review panel called the basis obsolete and unsupported. | VC06 | T3 | HIGH |
| CLM-0430 | Each of the 228 power converters in this old design needed a radiator bigger than a tennis court just to shed its own waste heat and stay within its operating temperature band. | VC03 | T3 | HIGH |
| CLM-0431 | This cell design might need over 30 times less shielding mass, from a coating 50 times thinner, than today's space solar cells, while still lasting for decades, according to computer models. | VC01 | T2 | MED |
| CLM-0440 | A 2026 computer model of a gigawatt-class space solar power beam finds it would barely disturb the density of the upper atmosphere's electrically charged layer, but would locally heat one part of it (the F-region) by several thousand degrees. | VC06 | T5 | LOW |
| CLM-0441 | A normal geostationary satellite needs a small, regular fuel-based nudge every year to stay in place. One 2019 design proposes cutting most of this fuel need for a solar power satellite by placing it in an orbit tilted by about 8 degrees that resists being pushed off station, and keeps the satellite pointing the right way passively using its symmetric shape and sunlight pressure. | VC04 | T2 | MED |
| CLM-0450 | An economic model from about 2011 of a small, first-of-a-kind demonstration solar power satellite found its electricity would cost over 23 USD per kilowatt-hour if privately financed, against roughly 1 USD per kilowatt-hour that the source uses for comparison (generator power at US forward military bases, where its own estimates run from about 0.9 to 27 USD); only full government funding of both development and hardware brought the price down to 0.15 USD per kilowatt-hour, which the authors say may then be competitive on optimistic ground-system costs, in a case they judge unlikely. | VC10, XC02 | T5 | MED |
| CLM-0460 | The URSI working group's report proposes about 250 watts per square metre on bird-welfare grounds, and says the figure does not change with frequency. | VC06, XC03 | T2 | HIGH |
| CLM-0461 | The ionosphere absorbs about one part in a hundred thousand of the beam. It is not a meaningful loss. | VC06, VC07 | T0 | MED |
| CLM-0462 | A 2025 study by the OECD Nuclear Energy Agency and the US Electric Power Research Institute estimates that new large nuclear plants built now would cost about 95 to 168 US dollars per megawatt hour. If the industry gets back to building reactors routinely, that could fall to about 56 to 87 dollars. Extending the life of existing plants is cheapest, at about 39 to 62 dollars. | XC02 | T3 | HIGH |
| CLM-0465 | Converting the 2022 European Space Agency space solar power cost estimate onto the same basis gives roughly 27 to 110 pounds per megawatt-hour depending on percentile, unit count and return rate used. | XC02 | T0 | MED |
| CLM-0466 | NASA's report prints the computer code for its cost-learning formula, and running that code gives back the report's own module and servicer costs. The one-line formula written in words just above the code is mistyped, so anyone working from the words rather than the code would get a badly wrong answer. | XC02 | T0 | MED |
| CLM-0467 | Using much more efficient solar cells would let the whole station be built with far less mass and far fewer launches, and that combined effect cuts the electricity cost by more than a launch-price cut alone would. | XC02 | T0 | MED |
| CLM-0468 | In this model, free launch alone, with every other input unchanged, still leaves the electricity cost at about 0.10 dollars per kWh or more, because building and replacing the hardware itself costs too much. | XC02 | T0 | HIGH |
| CLM-0469 | The same U.S. cost model puts new nuclear power at roughly 49-137 US dollars per megawatt-hour and geothermal power at roughly 41-149 dollars per megawatt-hour by 2030-2050, depending on the cost-case assumed. Both technologies can run almost continuously (90 percent of the time or more), so, unlike solar and wind, these figures are already close to a "firm power" cost without needing extra storage. The same source gives building and running costs for new gas power plants and coal plants, but does not publish a matching cost-per-unit-of-electricity figure for them in this edition. | XC02 | T3 | HIGH |
| CLM-0470 | The same financial-industry report separately estimates what it costs to make solar and wind power as reliable as an always-on power plant, using the rules each U.S. grid operator actually applies to plan for enough capacity at peak demand. Across six major U.S. grid regions, firmed solar (without its own storage) costs about 92-135 dollars per megawatt-hour; solar with four hours of battery storage, also firmed, costs about 115-167 dollars per megawatt-hour. Firmed onshore wind costs about 87-118 dollars, and wind with storage about 103-146 dollars. The report itself is careful to say this "firming cost" is not the same as the cost of building a resource that can run for a full 24 hours a day on one site; it reflects each region's own accepted method of crediting how much a plant contributes to keeping the lights on at peak times. | XC02 | T4 | HIGH |
| CLM-0500 | The same formula for how much microwave power a beam can carry before it destabilises the upper atmosphere gives 425 watts per square metre at one textbook set of conditions and a typical 189 across thousands of real radar measurements. That is not two methods disagreeing; it is one method fed different starting numbers. | VC06, VC07 | T2 | MED |
| CLM-0501 | A 2024 Chinese satellite design concept plans to beam down microwaves twice as strong as CASSIOPeiA's own typical figure, and its designers do not appear to have considered the upper-atmosphere stability question at all. | VC05, VC06, VC07 | T2 | MED |
| CLM-0503 | Under the international radio rules as revised at the 2023 world radio conference, there is no radio-frequency allocation for beaming power from space to Earth at either of the two frequencies CASSIOPeiA-type designs use. The international studies that might lead to one are due to report to a conference in 2031, a year after the first working system that a 2025 UK report forecasts for 2030, and before its 2033 and 2036 steps; the report says its dates are estimates. | XC01 | T4 | MED |
| CLM-0504 | None of the main CASSIOPeiA-related documents in the register mentions any named safety or exposure standard, or describes any restricted area around the receiving site, anywhere in nearly 300 pages. | VC06, VC07, XC01 | T2 | HIGH |
| CLM-0508 | An independent university research group has modelled a solar-cell design that could need over thirty times less protective shielding weight than today's space solar cells, but the design exists only in computer simulation. | VC01 | T2 | MED |
| CLM-0511 | The first real, built, and measured version of CASSIOPeiA's beam-steering hardware converts electricity to radio power at 42%, against about 80% for the amplifier alone and 65% for the amplifier with its circulator, once every real component is counted rather than just the amplifier chip. | VC05, VC06, VC07 | T2 | HIGH |
| CLM-0512 | The small prototype achieved a beam strength close to what a real system would use, but only over an area the size of a small table, using about 672 watts of radio power. | VC05, VC06, VC07 | T2 | MED |
| CLM-0513 | The most credible real, flown demonstration of space-based wireless power transmission achieved milliwatts of power over centimetres inside a single small satellite, at a little over half its own predicted efficiency, and its own scientists do not attempt to say what this means for a full-scale power station. | VC05, VC06 | T1 | HIGH |
| CLM-0515 | Nearly half of the grant money the UK government announced in 2023 and 2024 for its space-based solar power innovation competition was awarded to three projects named after the CASSIOPeiA design; none of the other six awards was tied to a named satellite design. | XC01, XC02 | T3 | HIGH |
| CLM-0516 | Public money funded a real piece of hardware that was built and tested, not just another report -- a rare outcome in this field -- even though what it found was not entirely flattering to the design. | VC05, VC06, VC07, XC01 | T3 | MED |
| CLM-0517 | Every date in the plan -- the ground demo (2026), the demo mission (2027-28), 2030, 2033 and 2036 -- is a hope, not a booking, and the report that states them says so itself. | VC10, VC11, XC02 | T4 | HIGH |
| CLM-0518 | As last updated in February 2026, the UK government's own webpage on this topic describes two research reports it paid for and links its earlier grant competition, with no announced plan to fund anything further. In 2025 an advocacy group that had praised past government support warned that, without visible support and significant funding, UK leadership would fade. | XC01 | T5 | MED |
| CLM-0519 | The UK government has not announced any money for the next stage of this design since its 2022-2024 competition, and its own webpage, last updated in February 2026, promises none. | XC01, XC02 | T0 | MED |
| CLM-0522 | The UK study used a 20% return requirement, based on what institutional investors are expected to want. The US study used 3%, on a one-line assumption of government funding, and did not test what a different rate would do. | XC02 | T4 | HIGH |
| CLM-0523 | Changing the assumed investment-return rate moves a cost estimate a lot on its own, but the cheap study already uses the tough rate and the expensive study already uses the gentle one, so making the rates match does not bring them together. | XC02 | T0 | MED |
| CLM-0524 | Every UK-specific or typical-country cost-of-capital figure found sits well below the 20% rate Frazer-Nash used, even at the top of DESNZ's published range for floating offshore wind; only a global dataset covering the riskiest countries in the world reaches as high as 20%, and only at its extreme end. | XC02 | T4 | HIGH |
| CLM-0525 | If a gentler, arguably fairer investment-return rate is used instead of Frazer-Nash's tough 20%, its own cost figure gets even lower, not higher -- but this does nothing to close the huge gap with the US study, because the gap does not come from the discount rate. | XC02 | T0 | MED |
| CLM-0527 | The tough interest rate Frazer-Nash used for CASSIOPeiA makes its low headline cost figure more impressive, not less, when checked against real-world comparable rates -- but that says nothing about whether the other numbers feeding into that figure are right. | XC02 | T0 | MED |
| CLM-0528 | NASA's assumptions imply a high cost per kilogram delivered to the power station's actual orbit, mainly because NASA assumes every launch carrying hardware needs twelve extra fuel-only launches to refuel it for the climb from low orbit. | VC10, XC02 | T0 | HIGH |
| CLM-0531 | Neither the UK nor the US figure for what it costs to get a kilogram of hardware into the power station's real orbit is based on an actual, completed transaction. Both are assumptions about future launches, and NASA says it makes no claim that its assumed launch price is reliable. For the same rocket and the same starting price per launch, the two figures differ mainly in how hardware is assumed to get from low orbit to its final orbit, and that is what changes the number of launches needed. | VC10, XC02 | T4 | MED |
| CLM-0532 | A different space-solar-power company's own 2024 analysis estimates that a single non-reused Starship launch to low orbit would cost about $665 per kilogram, and that costs could fall toward $500/kg within a decade. | VC10, XC02 | T4 | MED |
| CLM-0533 | All the rockets in the world together put about 2.7 million kilograms into orbit in 2025, about a fourteenth of the mass of one solar power satellite design from 1978 (about a thirteenth for the main 1978 reference design). | VC10, XC05 | T3 | HIGH |
| CLM-0534 | SpaceX's published Falcon 9 price is lower per launch than the 100 million dollars both the US and UK studies assumed, but higher per kilogram, because Falcon 9 carries far less than the rocket those studies assumed. A real government order in late 2025 for five missions averaged more than 100 million dollars each. Neither figure allows for getting from low orbit up to the power station's real orbit. | VC10, XC02 | T6 | MED |
| CLM-0535 | By late July 2026, after 13 test flights, SpaceX's Starship rocket had still not been launched into low Earth orbit, and its test of transferring fuel between two of its craft in space had not yet flown. It flew five times in 2025. | VC10 | T6 | MED |
| CLM-0538 | The US and UK studies are not just using different toughness levels for the same test -- they are answering different questions. The US study asks "what would this cost the government to build and pay for entirely by itself," which is why its rate is so low. The UK study asks "what return would a private investor need to put money in," which is why its rate is so high. Whether the same would hold for a real UK project like the new nuclear power station has not been checked against a held source. | XC02 | T4 | MED |
| CLM-0539 | A UK consultancy, working for the European Space Agency and using the same design as its reference point, actually published a full weight breakdown -- something the original 2019 paper never did. It comes out lower than the headline claim, at about 0.70 kilowatts per kilogram rather than 1, even though it leaves out several categories of weight altogether. It also rates one of the satellite's power-conversion stages as barely more than an idea on paper, and its input notes say the lightest case for the radio equipment is an expert's judgement, not something anyone has measured or built. | VC01, VC02, VC04, VC05, VC06, VC07, VC11 | T4 | MED |
| CLM-0543 | The US national energy laboratory's 2025 projections have the cost of a four-hour grid battery falling by 2050 in every case it models, to roughly 100 to 300 dollars per kilowatt-hour of storage depending on how fast costs fall. | XC02 | T4 | MED |
| CLM-0544 | The UK government's own cost model expects deep geothermal power, which it treats as an early-stage technology, to become much cheaper by 2050 than a first-of-a-kind plant would be in 2030. | XC02 | T3 | MED |
| CLM-0546 | No source in the register, and none found in a general web search, gives a rigorous estimate of what firmed solar or wind power will cost in the 2040s or 2050s. The two pieces that exist (a firming-cost estimate for 2026, and a future battery-cost trend) have not been joined in any source found. | XC02 | T0 | MED |
| CLM-0547 | Building about 1.46 to 2 million identical satellite modules means the production line has to double its total output about 20 to 21 times over, starting from the first one built. | XC02 | T0 | HIGH |
| CLM-0552 | The international study planned for 2031 is aimed at stopping wireless power transmission from disturbing other radio users. It is not, on its own wording, aimed at giving wireless power transmission its own protected slice of spectrum the way other radio services get. The item is printed in brackets and is due to be reconsidered in 2027, so it is not yet settled. | XC01 | T1 | MED |
| CLM-0559 | None of these five problems, on its own, proves space solar power is impossible for the UK. But solving all of them at once, on the timeline proponents state, would require several separate hard problems to go well together, and right now nobody has the evidence to say confidently that any of them will. | XC02 | T0 | MED |
| CLM-0600 | NASA's launch price was optimistic, not pessimistic. The expensive part is its assumption that each payload needs twelve refuelling flights, which multiplies the cost thirteen times. | VC10, XC02 | T0 | HIGH |
| CLM-0601 | In one model, swapping refuelling flights for electric-propulsion tugs cuts the electricity cost by about two thirds. NASA's own analysis reports 62 per cent total cost savings for its electric-propulsion variant, and a critic said that using tugs with electric propulsion would be a far more efficient approach. The three are not fully independent, because the model uses NASA's own inputs. | VC10, XC02 | T0 | MED |
| CLM-0660 | The 2019 CASSIOPeiA paper does not discuss electric propulsion for getting the satellite to its orbit. It only prices delivery using ordinary rocket-fuel-based transfer methods. | VC10 | T2 | HIGH |
| CLM-0662 | NASA's own report lays out a timeline: build in the 2030s, launch and move to the final high orbit in the 2040s, then run the system from 2050 to 2080. | VC10 | T3 | HIGH |
| CLM-0666 | NASA also modelled a third option: a rocket that flies itself all the way to the final orbit without refuelling, at the cost of carrying so much of its own fuel that it can only deliver about a fifth of its normal cargo. This cuts cost a lot but barely cuts emissions, because so many more rockets have to be built. | VC10 | T3 | HIGH |
| CLM-0667 | One company's design deliberately avoids the standard high orbit used by other designs, because it believes waiting for compatibility with existing satellites there would delay deployment by decades. | VC10 | T4 | MED |
| CLM-0668 | The same company's own numbers show that, using the identical rocket and the identical (chemical) engine type throughout, simply choosing a higher orbit roughly quadruples the cost per kilogram - a separate effect from which propulsion type is used. | VC10 | T4 | MED |
| CLM-0670 | Caltech has two different space-solar-power efforts. One is a paper design that assumes a normal rocket-fuel-based trip to a high orbit. The other is a small test that actually flew, but only in low orbit near Earth, testing hardware pieces, not a trip to a higher orbit. | VC11 | T5 | MED |
| CLM-0672 | A 2020 paper by the builders of NASA's NEXT-C ion engine and NASA engineers gives the engine's ground-test performance; NASA's 2024 space-solar-power cost report names this engine but gives no performance figures for it. This is a real, tested engine, not a hypothetical one. | VC04 | T4 | HIGH |
| CLM-0673 | Electric thrusters get roughly seven to fourteen times more push per kilogram of fuel than ordinary rocket fuel does, based on real, published engine performance figures. | VC04 | T4 | MED |
| CLM-0675 | Some real satellites use a mixed approach: a normal rocket engine does most of the work of reaching high orbit, and small electric thrusters only fine-tune the final position. This is much faster than doing the whole trip electrically: 4 to 74 days on the eleven flights reported. | VC10 | T4 | HIGH |
| CLM-0676 | A peer-reviewed study calculates that solar panels lose a real, measurable amount of power, up to about 15% in the worst case tested, just from spending months passing through Earth's radiation belts during a slow electric-propulsion trip to high orbit. Thinner protective glass on the cells makes this worse; starting from a higher point in the transfer orbit makes it better. | VC04 | T2 | HIGH |
| CLM-0682 | A 2013 design paper, written years before and independently of NASA's 2024 study, states almost the same speed-change requirement for reaching high orbit that NASA later published - two unconnected sources agreeing on the same physical number. | VC04 | T5 | MED |
| CLM-0683 | If NASA's own numbers for switching to electric propulsion are applied to the existing side-by-side comparison of the big institutional cost studies, the gap between the cheapest and most expensive study shrinks from about twenty-to-thirty-five times down to about seven-to-ten times. That is a large improvement, but the studies still do not agree. | XC02 | T0 | MED |
| CLM-0687 | The Chinese design says how it gets to orbit. Rockets carry the parts to a low orbit. A reusable space tug then moves each part up to the high orbit, where they are put together. The paper says that assembling it high up lowers the risk of hitting space debris, because there is much less debris there. The tug comes back down to be refuelled and to have its solar panels swapped. The design does not say whether the tug burns fuel or uses electric thrusters. | VC10, VC11 | T2 | HIGH |
| CLM-0688 | The Chinese design shields the satellite parts from radiation during the climb to high orbit, using the tug itself as the shield. It also plans to replace the tug's own solar panels in low orbit, along with refuelling it, so that the tug can be reused. | VC04, VC10 | T2 | HIGH |
| CLM-0689 | The Chinese team published its own cost figures for a one-gigawatt system: about 17.3 billion US dollars over 30 years, which they put at about 6.6 US cents per kilowatt-hour. They say this is more than 30 per cent cheaper than their previous design. | XC02 | T2 | HIGH |
| CLM-0692 | The Chinese design's own summary table adds up: the parts weigh what the total says they weigh. Its claimed 12.3 per cent efficiency is sunlight-to-grid, which checks out against the area of the panels and the strength of sunlight in space. The antenna is a long thin strip, 100 metres by 10.5 kilometres, at 5.8 gigahertz. | VC01, VC02, VC05 | T2 | HIGH |
| CLM-0693 | The formula used here for when a microwave beam starts to focus itself in the ionosphere has now been checked against the original 1980 paper that first published it. Every part matches: the constant, the way it scales with frequency, density and temperature, and the assumption that one correction factor is about one. | VC06 | T3 | HIGH |
| CLM-0694 | The scientist who published the threshold formula says a single threshold number does not really exist. Whether the beam becomes unstable depends on the size of the ripples it is making, and as the beam gets stronger, smaller ripples start to grow too. He also warns the threshold drops very low when the beam happens to run almost along the Earth's magnetic field. | VC06 | T3 | HIGH |
| CLM-0695 | The 1980 paper says the SPS beam is expected to cause the ionosphere to focus it. It backs this with radar measurements from Arecibo, made in a different heating regime from the one an SPS beam would create, showing the predicted ripple sizes actually appear, roughly a kilometre across, and that they change the local electron density by about 5 per cent. The ripples form in seconds and fade in minutes. | VC06 | T3 | HIGH |
| CLM-0696 | NASA's own comparison table shows exactly why its headline "0.02 to 0.05 dollars per kilowatt-hour" figure needs care. The cheapest entries in that table are wind and solar without storage, which are not firmed: they generate only when the wind blows or the sun shines. The solar panel entry with storage barely changes how much of the time it can generate, only 30 percent instead of 29 percent, so it is not a round-the-clock supply either. The two entries that genuinely can run almost all the time, nuclear and geothermal, are priced at the top of the range, not the bottom, and so are solar-thermal power with heat storage and hydro. | XC02 | T3 | HIGH |
| CLM-0697 | The Chinese 6.6 cent figure ignores the cost of money. Once you charge interest on the capital, the same numbers give about 10 cents at a low interest rate and 21 cents at a high one. Even so, NASA's own figures stay between about 2 and 16 times more expensive, depending which of NASA's cases you pick. | XC02 | T0 | MED |
| CLM-0698 | The Chinese cost table states a transport price of 1,000 dollars per kilogram in its column heading, but its own numbers only work out at about 482 dollars per kilogram. Every row shows the same mismatch, so it is not a rounding error. Either way the figure is far below NASA's assumed 11,050 dollars per kilogram - between 11 and 23 times below, depending which of the two you use. | VC10, XC02 | T0 | MED |
| CLM-0700 | A 1980 JPL paper already worked out how to move a two-thousand-tonne payload from low orbit to high orbit using electric thrusters. It needed 150 megawatts of electrical power and took between 160 and 213 days depending on which thruster was used. The magnetoplasmadynamic option needed only 23 thrusters against 920 to 2,000 for the ion options. | VC04, VC10 | T3 | HIGH |
| CLM-0701 | The 1980 study assumes each kilogram being moved has 75 watts of electrical power pushing it. One real electric satellite manages between about 2 and 9 watts per kilogram of its whole launch weight. The study's figure is 8 to 33 times that, but it counts only the cargo, so on a like-for-like count the gap would be smaller. That assumption, more than the thruster type, is why its travel times look so short for such a huge payload. | VC04, VC10 | T0 | HIGH |
| CLM-0702 | Electric trips from a low orbit to a high one took four to seven months on real flights and in most models held here, and NASA's four-month figure is at the fast end of that. One European study expects at least 20 months for its modules, because the time depends on how much thrust each tonne gets. | VC10 | T4 | MED |
| CLM-0710 | The second European study, which had never been obtained here, is now in the archive. It puts the cost of a two-gigawatt first system at 213 euros per megawatt-hour, leaving out research and decommissioning costs, which is about five times the cost of solar power today and ten times its projected cost in 2050. | XC02 | T4 | MED |
| CLM-0714 | The 2021 UK study by Frazer-Nash Consultancy proposed that the satellite fly itself to its final orbit, using its own solar panels to run its own electric thrusters. Chemical tugs would take the parts only partway, to about 5,900 km, just above the inner radiation belt, where the satellite would be built. The study said the plan needed further work and gave no figures for the self-powered trip. | VC04, VC10, VC11 | T4 | HIGH |
| CLM-0715 | The 2021 UK study assumed one extra fuel launch for every payload launch; NASA's 2024 study assumed twelve. The reason, which neither study states, is not that they disagree about the price of a rocket: the UK plan used chemical rockets only part of the way up, to about 5,900 km, and then switched to electric, while NASA's used chemical rockets all the way to the top. The two studies also assumed different amounts of cargo reach the top per launch. | VC10 | T4 | HIGH |
| CLM-0741 | A 2026 independent assessment says China is unlikely to have a working weapon that could shoot down a satellite as high as geostationary orbit, because only one test, in May 2013, is known to have targeted altitudes above low orbit, and such a weapon would likely need several tests to be militarily useful. The assessment adds that this capability is likely still being tested or developed. | XC04 | T4 | HIGH |
| CLM-0742 | A 2026 assessment lists thirteen Chinese anti-satellite tests since 2005; only one is recorded as going far above low orbit, to about 30,000 km in May 2013, short of the roughly 36,000 km of geostationary orbit given in the same assessment, and the assessment records it as probably just a rocket test with no known target. | XC04 | T4 | HIGH |
| CLM-0743 | Two separate expert bodies looked at the same 2013 Chinese launch and disagreed about what it was: one calls it probably a rocket test, the other says it hints at a basic ability to attack satellites very far from Earth. Neither says a satellite that high has ever actually been shot down. | XC04 | T4 | HIGH |
| CLM-0744 | The higher a satellite orbits, the longer the warning it gets: minutes in low orbit, but several hours at geostationary altitude, and the 2026 assessment doubts a missile could still track a target that had moved during those hours. | XC04 | T4 | MED |
| CLM-0745 | The 2026 assessment says that if China physically destroyed a satellite, it would create long-lasting debris that would also endanger its own satellites, would be relatively easy to identify as the attacker, and would face international condemnation, so China would have to weigh these costs against less destructive options such as jamming or blinding. | XC04 | T4 | MED |
| CLM-0746 | A 2025 assessment by a US think tank lists which countries hold which kinds of anti-satellite capability: China and Russia hold nearly all of them, while Iran and North Korea hold jamming, spoofing, cyber attack and attacks on ground infrastructure but not missiles that can reach satellites. North Korea is also listed as able to set off a nuclear explosion in space or the upper atmosphere. | XC04 | T4 | HIGH |
| CLM-0747 | A 2025 assessment by a US think tank says a Russian satellite believed to collect signals has spent time near eight commercial communications satellites in geostationary orbit, and that some analysts think it may have come within about 5 km of one in July 2024 and less than 1 km of another in January 2025. | XC04 | T4 | MED |
| CLM-0748 | The international radio standard says collisions in geostationary orbit happen at around 500 metres per second, far slower than in low orbit, so they are less catastrophic, but it also says a satellite has little chance of surviving any collision. | VC12, XC04 | T3 | HIGH |
| CLM-0749 | A 2010 international radio recommendation said the smallest object that could then be tracked in geostationary orbit was just under a metre across, against 30 centimetres in low orbit, so smaller debris up there went unseen, and it said other break-ups at that altitude had quite likely gone unnoticed. | VC12, XC04 | T3 | HIGH |
| CLM-0750 | The 2020 edition of the international debris guidelines says a retiring geostationary satellite should climb at least 235 km above its working orbit, plus an extra allowance that depends on how large and light it is, and the 235 km is made of 200 km of protected zone plus 35 km for the way gravity nudges the orbit back down. | VC12, XC04 | T3 | HIGH |
| CLM-0751 | Working the international disposal formula through by hand shows that for a very large and very light satellite the extra height it must climb at retirement is dominated not by the fixed 235 km allowance but by the push of sunlight on it, and that for anything lighter than about 8.5 kilograms per square metre facing the sun that sunlight term is the larger of the two. | VC04, VC12, XC04 | T0 | HIGH |
| CLM-0752 | ESA's 2026 report says that nothing naturally removes objects from geostationary orbit the way the atmosphere slowly clears low orbit, so a retiring satellite there has to be deliberately moved out and kept out for at least a century. | VC12, XC04 | T3 | HIGH |
| CLM-0753 | ESA's 2026 report says the world is not clearing satellites out of orbit well enough, that even the usual 90 per cent success target would not reduce the amount of debris on its own, and that the figure needs to rise to nearly 100 per cent. | VC12, XC04 | T3 | HIGH |
| CLM-0754 | ESA's 2026 report projects that collisions between existing pieces of debris will keep making more debris in low Earth orbit even if nothing else is ever launched, and it makes no such projection for geostationary orbit at all; nothing in the register says whether the same runaway effect would happen up there or not. | VC12, XC03, XC04 | T3 | HIGH |
| CLM-0755 | NASA's July 2026 debris bulletin counts 33,098 tracked objects in orbit as of 4 May 2026, of which 18,189 are satellites and 14,909 are spent rocket stages and debris, but it gives no figures at all for geostationary orbit specifically. | VC12, XC04 | T3 | HIGH |
| CLM-0756 | The international space debris guidelines are advice, not law: ESA's own report says they are a starting point for national rules and technical standards, and that it is up to each country, operator and manufacturer whether and how to apply them. | VC12, XC01, XC04 | T3 | HIGH |
| CLM-0757 | In its own report on the February 2022 attack, Viasat says the attacker got in through a misconfigured VPN device, reached the network management system, and then sent the network's own ordinary management commands to tens of thousands of customer modems at once, wiping enough of their memory to knock them off the network without permanently breaking them. | VC09, XC04 | T4 | HIGH |
| CLM-0758 | Viasat's own report, about five weeks after the attack, says it had found no evidence that the satellite itself or its main ground stations were directly involved, and that its analysis of affected modems found no impact on their physical or electronic parts and no evidence of tampering with modem software or firmware images, yet the service still went down across much of Europe. | VC09, XC04 | T4 | HIGH |
| CLM-0759 | The UK's national cyber security agency said in May 2022 that Russia was almost certainly behind the attack on Viasat, that it started about an hour before the invasion of Ukraine began, and that wind farms in central Europe were among those affected. | XC04 | T3 | HIGH |
| CLM-0762 | The civil space command-link security standard says exactly which parts of a message it protects and which it does not: it fully protects the command payload, only partly protects the message header, and leaves several control and status channels unprotected altogether. | VC09, XC04 | T1 | HIGH |
| CLM-0763 | The civil space link security standards deliberately do not say which encryption to use, do not describe how to build a real system, and leave the choice of algorithm to the mission; a companion document adds the key management, rekeying and replay protection needed to run the protocol. | VC09, XC04 | T1 | HIGH |
| CLM-0764 | A 2020 US presidential directive sets out what good cyber security for satellites looks like, including making sure a satellite only obeys commands from an authorised sender, but it says agencies and operators "should" do these things and states in its own text that it creates no legally enforceable obligation. | XC01, XC04 | T1 | HIGH |
| CLM-0765 | Searching all fourteen security and defence sources for anything about insurance or liability turns up no premium, no cover limit and no liability figure for any satellite; the only real mention is one reference to the 1972 space liability treaty. | XC02, XC04 | T0 | MED |
| CLM-0780 | The UK rules for connecting power stations set a hard limit on how much generation one fault may disconnect at once: 1800 MW for a fault on the station's own connection, and nothing at all for a fault on a single transmission line. | VC08, VC09 | T1 | HIGH |
| CLM-0782 | UK rules limit the overhead line between a generating unit and the grid to 5 km for units producing at least 2000 gigawatt-hours a year and 20 km otherwise. A 2 gigawatt plant counted as one unit would cross that threshold even if it ran only about 11 per cent of the time, but the rules define a generating unit as any apparatus which produces electricity, and counted that way a receiving site made of many converters would fall under the 20 km limit. Which reading applies is not settled. | VC07, VC08 | T0 | HIGH |
| CLM-0783 | Under Great Britain's grid code as the system operator's 2024 guidance describes it, an inverter-based generator must be able to export or import reactive power equal to about a third of its rated output, usually measured where it joins the grid, and the guidance says it should reach 90 per cent of a requested change within one second. | VC08 | T3 | HIGH |
| CLM-0786 | In December 2025 the UK system operator changed its own connection standard to allow a single large direct-current converter to carry more power, because the old 1320 megawatt cap was forcing offshore wind farms to build extra cables, and it priced the extra frequency support at about 12 million pounds a year. | VC08, XC02 | T3 | HIGH |
| CLM-0787 | The UK harmonic planning levels for networks above 230 kV set total waveform distortion at 3 per cent, with the largest single-harmonic level being 2 per cent at the fifth and seventh harmonics. These are levels for the network as a whole, and each connection gets only a share of them. The document is a recommendation, and it is careful to say which of its words are mandatory. | VC08, XC01 | T1 | HIGH |
| CLM-0788 | If the ground station has several hundred converter units and their diversity is declared, the harmonics standard lets their high-frequency distortion partly cancel while their low-frequency distortion adds up directly, so the hardest limits to meet are on the low-order harmonics below the fifth and not on the high-frequency switching harmonics that inverter designers usually worry about. Without that declaration the standard requires all their distortion to be added up directly, and the low-order harmonics are no longer singled out. | VC08 | T0 | MED |
| CLM-0789 | A UK inverter-based generator must stay connected through a complete loss of grid voltage lasting up to 140 milliseconds, then get back to at least 90 per cent of its output within half a second, and must remain stable for up to 30 minutes afterwards. | VC08 | T3 | HIGH |
| CLM-0790 | Great Britain does not oblige an inverter-based generator to behave like a synchronous machine; it pays for that behaviour through a market. Plants that do offer it face a demanding specification, including being able to keep operating when the grid at its connection point has a short-circuit level of zero. | VC08, VC09 | T3 | HIGH |
| CLM-0791 | In 2024 the EU was moving towards putting grid-forming behaviour into its connection code, following a December 2023 recommendation, but the draft wording required it only where the national system operator asks for it. Britain and Australia already had their own versions. | VC08, VC09, XC01 | T3 | HIGH |
| CLM-0792 | Under the UK's retained version of the EU connection code, any generator connecting at 110,000 volts or more, or above 75 megawatts, faces the strictest category of requirements. Its reactive power envelope is capped, and synthetic inertia is something the system operator may ask for, not something the generator must have. | VC08, XC01 | T1 | HIGH |
| CLM-0793 | Britain's system operator plans to run the grid with less spinning inertia, and it sets that limit from the size of the biggest single generator loss it must survive, currently 1800 megawatts. | VC08, VC09 | T3 | HIGH |
| CLM-0795 | Britain's system operator says that at the lower inertia level it is moving to, losing 2000 megawatts at once would be enough to start disconnecting customers, and losing 3.3 gigawatts at once could cause a nationwide blackout. | VC08, VC09 | T3 | HIGH |
| CLM-0796 | Britain's system operator says its grid needs both spinning inertia and short-circuit strength, and gives a scale: a single 2 gigawatt coal station used to supply over 6,500 megavolt-amperes of that strength. | VC08, VC09 | T3 | HIGH |
| CLM-0797 | In December 2025 Britain's system operator said that 283 gigawatts of generation and storage, out of more than 700 gigawatts that had been waiting to connect, would be prioritised for connection, split between projects needed by 2030 and by 2035. | VC08, XC02 | T6 | LOW |
| CLM-0798 | The American standard often named as the comparator, IEEE 1547, covers generators joining local distribution networks. A gigawatt-scale ground station would join the high-voltage transmission network instead, so a different standard applies, and that one was not obtained. | VC08, XC01 | T4 | MED |
| CLM-0799 | A search of a large research index on 4 September 2026 found 2551 papers on space-based solar power and not one whose title or summary mentions grid codes, fault ride-through, reactive power, harmonic distortion, grid-forming or power quality. | VC08, VC09 | T0 | MED |
| CLM-0800 | A 2025 power-engineering paper does model space-derived solar power inside an electricity network, but it uses a nine-bus textbook test system and only steady-state calculations, so it does not test any of the connection rules a real plant would have to meet. | VC08, VC09 | T2 | HIGH |
| CLM-0810 | A 2020 modelling study estimated that, across its whole operating life from 2040 to 2100, the 1978 NASA/DOE space solar power design would produce about 112 grams of CO2-equivalent per kilowatt-hour for the silicon version and about 123 grams for the gallium-arsenide version, counting emissions from the rocket launches. | XC03 | T5 | HIGH |
| CLM-0811 | In a 2020 modelling study of the 1978 NASA/DOE space solar power design, the carbon per kilowatt-hour fell the longer the satellites were assumed to keep running, because the fixed launch and manufacturing emissions spread over more electricity; but the paper says it would take 67 to 77 extra years beyond the 30-year base case before that design matched ground solar panels, which it calls hard to envision. | XC03 | T5 | HIGH |
| CLM-0812 | A 2020 modelling study of the 1978 NASA/DOE design estimated that its ozone-depleting emissions, almost all from burning rocket fuel at launch and averaged per year over the 60-satellite programme, would be several times the yearly ozone-depleting impact of all human activity in the reference figures it used, and would exceed the planetary safe limit for ozone for the silicon version and come close to it for the gallium-arsenide version. | XC03 | T5 | HIGH |
| CLM-0813 | The paper's detailed component-by-component calculation gives a carbon figure five to six times higher than an older top-down calculation of the same 1978 design, and the paper is itself inconsistent about whether that older figure counted carbon dioxide only or all greenhouse gases. | XC03 | T5 | HIGH |
| CLM-0814 | A 2020 conference paper's own cost model put the whole 60-satellite programme of the 1978 US reference design at about 3.86 trillion US dollars in present-value terms for either version, and the cost of launching each kilogram of hardware at about 407 dollars for the silicon version and 375 for the gallium-arsenide version. The paper never says which year's dollars these are, although it gives its cost per kilowatt-hour for the same system in 2015 dollars. | XC02, XC03 | T5 | MED |
| CLM-0815 | The 2020 study of the 1978 NASA/DOE design did not count any warming from the microwave beams themselves, saying that is too hard to express as a CO2 figure and, on an outside estimate it quotes, would warm the planet by only about six thousandths of a degree even with thousands of satellites; it also assumed that at end of life the ground receivers are dismantled and the satellites recycled in orbit, an assumption the authors added because the original 1978 design never specified one. | XC03 | T5 | HIGH |
| CLM-0816 | In their 2020 study of the 1978 NASA/DOE design, the authors list their own weak points: only whole-system detail rather than part-by-part, a background database built mainly on European data and patched with substitutes, social impacts assessed only for supply-chain actors and workers because organisations would not share data, and seven impact categories that lacked weighting factors and could not be checked against any global or planetary-limit yardstick because none had then been defined for them. | XC03 | T5 | HIGH |
| CLM-0817 | The authors state openly that a space-solar-power advocacy non-profit paid for this study, that part of the reason was to test or support the environmental marketing claims made for the technology and potentially justify funding future missions, and that the lead researcher says the work was kept rigorous regardless; two of the four authors work for that funder. | XC02, XC03 | T5 | HIGH |
| CLM-0818 | A 2002 Japanese input-output study estimates that building and launching a 1978-design fleet of 60 solar power satellites would release about 20 grams of carbon dioxide for every kilowatt-hour they generate over an assumed 30-year life, counting carbon dioxide only rather than all greenhouse gases, and counting only production and launch rather than operation. | XC03 | T5 | HIGH |
| CLM-0819 | A 2002 Japanese input-output study estimates that if each new satellite were built with electricity from those already working, a fleet of 18 sized to Japan's 1995 electricity supply would come to about 11 grams of carbon dioxide per kilowatt-hour over an assumed 30-year life, roughly half the study's baseline, counting carbon dioxide only. | XC03 | T5 | HIGH |
| CLM-0820 | For comparison in the same units, a 2002 Japanese study of space solar power reports about 22 grams of carbon dioxide per kilowatt-hour for nuclear, 631 for gas, 846 for oil and 1,225 for coal, which it bases on earlier work by a Keio University research group rather than deriving them in the paper. | XC03 | T5 | HIGH |
| CLM-0821 | In a 2002 Japanese study of the 1978 US design, a table splits the estimated carbon dioxide from building and launching the system by part: solar cells are the biggest share at 57 per cent, the ground receiving antennas next at 25 per cent, propellant 11 per cent, the space transport vehicles 6 per cent (almost all of it the vehicle that moves cargo between orbits; the launch rockets themselves are under 1 per cent), and the satellite structure and the space bases under 1 per cent each. | XC03 | T5 | HIGH |
| CLM-0822 | In a 2002 Japanese study of the 1978 US design, building the launch rockets and the vehicles that move cargo and crews between orbits accounted for only about 6 per cent of the estimated carbon dioxide from building and launching the system, and adding their propellant brings the combined share to about 17 per cent, a sum the study itself does not give. | XC03 | T5 | HIGH |
| CLM-0823 | A 2002 Japanese study's carbon dioxide figures for space solar power come from Japan's 1990 economic input-output tables, with 405 industry sectors; they cover only building and launching the satellites, not running or maintaining them or delivering the power, and assume the satellites run for thirty years at full output around the clock. | XC03 | T5 | HIGH |
| CLM-0824 | This is a 2002 discussion paper that says it summarises two 1998 discussion papers by an overlapping group of authors, does not point to any later peer-reviewed version of itself, and cites none of the later UK-led work, which it predates, that redid the analysis by a different method, counting other greenhouse gases as well as carbon dioxide, and got a much higher figure. | XC03 | T5 | MED |
| CLM-0825 | The authors argue that the cost-based way of estimating carbon is too coarse for a custom-built industry like spacecraft, and they conclude that their own materials-and-process method should be preferred for space studies. | XC03 | T5 | HIGH |
| CLM-0826 | When the authors redid NASA's own 2024 figures for two satellite designs using their materials-based method instead of NASA's cost-based one, the carbon per unit of electricity came out about 11 to 18 per cent lower, and they say this suggests NASA's published figures for these two designs are too high. | XC03 | T5 | HIGH |
| CLM-0827 | The authors say NASA's 2024 carbon figures for two satellite designs came out of a model built on NASA's own cost estimates, and that NASA had not used this kind of model for a space solar power study in roughly twenty years, a period in which European researchers had developed methods NASA's assessment did not draw on. | XC03 | T5 | HIGH |
| CLM-0828 | The authors say ESA's own space life-cycle guidance advises against the cost-based method because it tends to overstate environmental impact, and the authors then add that the same method's lower level of detail can also cause it to understate impact. | XC03 | T5 | HIGH |
| CLM-0829 | The authors leave alumina, black carbon and water vapour from rocket exhaust out of their own carbon study because the atmospheric effects are too uncertain to quantify, even though in an earlier study of theirs almost all of the ozone damage came from exactly those launch emissions. | XC03 | T5 | MED |
| CLM-0830 | The authors say an environmental claim about a space technology counts for nothing unless a proper standardised life-cycle study backs it, and that whoever makes the claim should be able to hand the evidence to anyone who asks without making it hard to get. | XC03 | T5 | MED |
| CLM-0831 | This is a conference paper from October 2024 that does not claim to have been independently peer reviewed, states that it calculated no uncertainty figures, and argues it did not need the independent review that the life-cycle standards normally ask for because it says it is comparing methods rather than making an environmental claim. | XC03 | T5 | MED |
| CLM-0832 | A UK-commissioned study modelled the whole planned 2022-2080 fleet of space solar power satellites and found that, spread across all the electricity it would ever deliver, each unit of power would carry about 23.6 grams of CO2, which the authors say is similar to other renewable energy technologies. | XC03 | T2 | HIGH |
| CLM-0833 | This 2022 life-cycle study spells out exactly what it counted: the UK Space Energy Initiative's whole 2022-2080 roadmap, from early prototypes through to 25 full-size 2-gigawatt satellites, including their rockets, ground control and the receiving antennas on Earth, with each full-size satellite assumed to operate for about thirty years. | XC03 | T2 | HIGH |
| CLM-0834 | The authors say their model does not count the soot and aluminium oxide that rockets release into the upper atmosphere, because the science on how much these matter at different altitudes is still too uncertain, and the results table duly shows exactly zero for that category everywhere despite the study listing a method for it. | XC03 | T2 | HIGH |
| CLM-0835 | In a 2022 study, the research team compared its estimated carbon footprint per unit of electricity for a planned UK Space Energy Initiative programme, modelled on CASSIOPeiA satellites as an example design, with its own earlier assessment of the old NASA/DOE satellite design, made with the same calculation tool, which came out about five times higher, and said the newer design's much lower estimate was mainly because it needs far less steel, aluminium and concrete for its receiving antennas and can be built without astronauts. | XC03 | T2 | MED |
| CLM-0836 | A 2022 life-cycle study set its estimate of 23.6 grams of carbon dioxide equivalent per kilowatt-hour for the UK Space Energy Initiative's planned programme against an average of 233 grams for the UK energy fuel mix in the government's 2020 figures, and quoted a 2021 United Nations commission report's global ranges for coal, gas, nuclear, hydro, solar and wind to show roughly where that programme would sit among them. | XC03 | T3 | MED |
| CLM-0837 | Although the study's headline number is about carbon, its own results show ozone damage is the far bigger relative problem, at about 32 per cent of a safe planetary limit against under 5 per cent for carbon, and almost all of it comes from exhaust released during the rocket launches. | XC03 | T2 | HIGH |
| CLM-0838 | The authors of a 2022 life-cycle study of the UK Space Energy Initiative's planned space solar power programme said that, if the whole programme's emissions were spread evenly across its 58-year life, the electricity generated would pay back that carbon debt in under six years against the average carbon intensity of the UK energy fuel mix in the government's 2020 figures, which they called a hypothesis in the body of the paper but stated as a result in its summary, and the paper gave no equivalent energy payback time. | XC03 | T2 | MED |
| CLM-0839 | A 2022 European consultancy study for ESA calculated that launching one space solar power satellite of the SPS-Alpha type would release about 2.6 million tonnes of greenhouse gas, from roughly 760 Starship flights each responsible for about 3,400 tonnes. | XC03 | T4 | MED |
| CLM-0840 | This 2022 ESA-commissioned study gave a total tonnage of greenhouse gas for launching a satellite but never converted it into emissions per unit of electricity, and apart from one sentence giving nitrogen oxides a carbon-dioxide-equivalent factor it did not assess the high-altitude effects of rocket exhaust. | XC03 | T4 | HIGH |
| CLM-0841 | This 2022 study was written by two European firms under contract to the European Space Agency, and it cites none of the earlier life-cycle carbon studies of space solar power from Strathclyde or Japan, so on the evidence of its citations it is a separate line of work, not another voice from those research groups. | XC03 | T4 | HIGH |
| CLM-0842 | Nobody has yet cited the paper arguing that published space-solar-power carbon figures were produced by the wrong method, on either of the two citation databases checked, more than a year after it appeared. | XC03 | T5 | MED |
| CLM-0843 | Other research groups around the world are publishing on space solar power, but none of the works this search found takes a position on the argument about which carbon-accounting method is right, and this search found no new carbon-per-kilowatt-hour figure published since 2023. | XC03 | T5 | MED |
| CLM-0845 | NASA states in its own report that its carbon figures come from a method that converts money spent, by industry sector, into emissions, combined with terms based on mass and area. | XC03 | T3 | HIGH |
| CLM-0846 | NASA's report says its carbon figures leave out the effects of rocket exhaust released high in the atmosphere, and in several places says those effects are assumed to be worse than releasing the same emissions at ground level, but it never says how much worse. | XC03 | T3 | HIGH |
| CLM-0849 | The range of 13 to 43 grams that NASA compares its satellites against comes from one US laboratory's dataset, and the two ends are the middle values for two different technologies, wind and solar, not the spread of possible values for either. | XC03 | T5 | HIGH |
| CLM-0850 | NASA does test how its carbon figures move if assumptions change, and under its most favourable combination they fall by roughly 86 to 89 per cent, to around 4 grams per kilowatt-hour; but the report prints that best-case number differently in three places. | XC03 | T3 | MED |
| CLM-0851 | NASA itself warns that its method assumes cost and emissions move together, which may not match what is actually measured, and that costs can fall without emissions falling; it describes the whole study as a first approximation and never states a carbon payback time. | XC03 | T3 | HIGH |
| CLM-0852 | Checking the study's own sums, its headline carbon-per-kilowatt-hour figures are averages across all sixty satellites over the whole programme's life, not the figure for one satellite, and the numbers add up correctly. | XC03 | T5 | HIGH |
| CLM-0853 | The wide range of published carbon figures for space solar power is not simply disagreement: most of it separates into two causes, which calculation method was used and which satellite design was assessed, and the method effect does not even point the same way in every case. The lowest published figure also counts carbon dioxide alone, while the others count all greenhouse gases, so part of the spread is a difference in what was counted. | XC03 | T5 | MED |
| CLM-0854 | The IPCC's fifth assessment gives typical whole-life carbon figures per unit of electricity of about 820 grams for coal, 490 for gas, 12 for nuclear, 24 for hydro, 27 for concentrated solar, 41 to 48 for solar panels and 11 to 12 for wind. | XC03 | T3 | HIGH |
| CLM-0855 | A 2024 peer-reviewed study says earlier life-cycle assessments of rockets may have understated their climate impact by a hundred to a thousand times, because they left out what exhaust and burning-up aluminium do high in the atmosphere; but it measures whole launch programmes rather than emissions per kilogram launched. | XC03 | T2 | HIGH |
| CLM-0860 | An open-source antenna modelling package puts the first side peak of a beam in the right place, to better than three parts in ten thousand, for the one antenna layout tested. A separate finding about how strong it reports one feature to be has been withdrawn, because it reversed when the aperture was reconstructed in an equally reasonable way. | VC05, VC06 | T0 | HIGH |
| CLM-0861 | A published software package ships its main engine to the wrong folder, so the package cannot find its own engine, and the installation reports success either way. | VC05 | T0 | HIGH |
| CLM-0862 | Switching a power satellite to the higher of the two candidate frequencies makes the beam five and a half times more intense on the ground, not less - but only if the antenna can keep its beam actively focused on the receiver. | VC05, VC06 | T0 | HIGH |
| CLM-0863 | A published figure suggesting that modelling a solar power satellite beam needs ten million million times more rays than the available software could handle turns out to describe the cost of one way of doing the sum, not the difficulty of the problem. | VC05, VC06 | T0 | HIGH |
| CLM-0864 | The whole beam calculation for a gigawatt power satellite runs in fifteen seconds on one core of a laptop. | VC06 | T0 | HIGH |
| CLM-0865 | For a power satellite in high orbit, the beam is almost exactly as concentrated where it passes through the ionosphere as it is at the ground, so the two figures can be compared. For a low-orbit satellite they cannot. | VC06, XC01 | T0 | HIGH |
| CLM-0867 | The 1978 report states a peak beam intensity, a collection efficiency and a total radiated power. Those three numbers cannot all be right together: they imply a beam about 5 to 7 per cent more sharply peaked than the antenna design described in the same report can produce. | VC06 | T0 | MED |
| CLM-0868 | The beam shape drawn in the 1978 report narrows slightly faster just outside its peak than the antenna design in the same report can produce. The gap is three to four per cent, which is small and near the limit of what a hand-drafted figure can be read to. | VC06 | T0 | LOW |
| CLM-0869 | The 1978 reference report gives two different figures, 88 and 89 per cent, for how much of the beam lands inside the same 5 km circle on the ground. | VC06, VC07 | T3 | HIGH |
| CLM-0870 | Recomputing the 1978 design from its own stated parameters reproduces its beam, its power and its own intercept figure of 95 per cent; the 88 per cent quoted elsewhere in the same report matches a different term in another breakdown of the same losses, and on the knowledge base's arithmetic the two breakdowns agree to about 0.3 per cent. | VC06, VC07 | T0 | MED |
| CLM-0871 | A table in the 1978 report has two arithmetic slips, and the report's own column total is enough to show which figure is wrong in each case. | VC05, VC06 | T0 | HIGH |
| CLM-0872 | A 1978 efficiency diagram has two of its numbers in the wrong boxes, which its own intermediate figures reveal and its bottom-line total cannot. | VC06, VC07 | T0 | HIGH |
| CLM-0876 | A common way to measure how long spectrum takes to reach users is to count the years from an international conference to the national licences. For the UK's 2018 3.4 GHz award that count may start from the wrong conference: the 2015 conference added no new footnote identifying that band for the UK's region; it amended an existing footnote that, as amended, identifies it, and the 2015 text does not show whether the identification itself was older. What these conferences do is identify bands for use, not for study. | XC01 | T1 | HIGH |
| CLM-0877 | A US regulator's order repeats a spaceflight news site's count of more than 3,500 Starlink satellites launched by October 2022. If that count is right, doubling from one unit to 3,500 takes nearly twelve doublings, and the company must have built at least as many as it launched, so that is a floor rather than an estimate - but the number is a journalist's, carried by the regulator rather than established by it. | XC02 | T5 | MED |
| CLM-0878 | By late 2022 the Starlink production line had roughly halved the distance to the scale a solar power satellite programme would need, about nine more doublings of output still to go. A doubling means building twice as many as every one built before, so nine of them is a very long way. | XC02 | T5 | MED |
| CLM-0879 | The only two full satellite designs here that say what voltage they run at disagree eight-fold, and the newer, smaller one runs at the lower voltage. The newer design's paper says its modular layout keeps the cables short, about 310 metres, and that this allows the lower voltage. | VC02 | T3 | MED |
| CLM-0880 | The Chinese design runs its solar panels at about 500 volts and steps up to a 5,000 volt main bus. It is the only modern satellite power distribution architecture recorded here. | VC01, VC02 | T2 | MED |
| CLM-0881 | Above roughly 55 volts, a spacecraft power system in low orbit can charge enough to arc and damage itself. NASA has a design standard for it, and the standard says the exact thresholds are not well known and have to be tested for. | VC02 | T3 | HIGH |
| CLM-0882 | For low Earth orbit NASA gives a voltage above which a power system may arc. For geostationary orbit it gives no equivalent voltage at all - the limits are set on how many electrons accumulate in a material and how strong the electric field inside it gets. The two orbits are not constrained in the same terms. | VC02 | T3 | HIGH |
| CLM-0883 | NASA puts the level at which internal charging starts causing failures at twenty billion electrons per square centimetre over ten hours, and designs to half that. It says no safety margin beyond that is specified. | VC02 | T3 | MED |
| CLM-0884 | The February 2022 KA-SAT attack was a break-in to a ground computer network. Nobody needed a rocket, and Viasat, which runs the network, said it found nothing showing the satellite itself was touched - which is what it could check, not a guarantee. On whether China can currently attack a satellite in high orbit with a missile, this register holds two outside views that differ: a research foundation judges it unlikely, and a US defence intelligence body reads a 2013 Chinese launch as suggesting the capability may exist. | XC04 | T4 | MED |
| CLM-0885 | A normal communications satellite spends about 50 metres per second of velocity change a year holding its slot. Working backwards from the 1978 design's own fuel budget, that design would spend about 360 a year against the push of sunlight on its very large area - seven times a normal satellite's entire budget - because it is vast and light. | VC04 | T0 | HIGH |
| CLM-0886 | One design builds its satellite from six hundred pieces put together in orbit. The other says it needs no assembly in orbit at all. Nothing in between is recorded. | VC11 | T2 | MED |
| CLM-0888 | Cable mass rises with the square of distance and falls with the square of voltage. The Chinese design says it can use a low five thousand volts because it is built as fifty modules, each sending its power only about 310 metres. The 1978 design sends all five gigawatts across the satellite as one system, and its report says it chose forty thousand volts to save conductor and equipment mass. | VC02 | T0 | MED |
| CLM-0889 | A beam sent from geostationary orbit cannot be focused to a small point. Diffraction sets a floor of kilometres across, and that floor is fixed once the antenna size and frequency are chosen. The only ways to make the beam more intense are a bigger antenna or more power, both of which are large and obvious. | VC06, XC04 | T0 | HIGH |
| CLM-0891 | The 1978 design says the size of its transmitting antenna was set by how much heat the array could shed, and elsewhere gives that limit as about 22 kW/m2 of radio power at the centre of the array. Working through the design's own numbers puts the centre at about 21.9 kW/m2, right at the limit, so the limit did set the size. Counted instead as waste heat from the transmitter tubes, the design would produce only about a fifth of the limit, but the report gives the number as radio power, not heat. | VC05 | T0 | MED |
| CLM-0895 | Twice a year, for about six weeks around each equinox, a satellite in geostationary orbit passes through the Earth's shadow once a night, for up to about seventy minutes. Keeping two gigawatts flowing through that would need roughly two and a third gigawatt-hours of batteries. The 1978 design carried about a two-hundredth of that, and only to keep its transmitter tubes warm. Over a year the shadow costs about one per cent of the time. | VC02, VC09 | T0 | HIGH |
| CLM-0896 | The patent describes measuring the incoming steering signal at scattered sensors, not at every antenna, and working out the values in between. The patent does not say how far apart those sensors are, which is the number that decides whether the method works. | VC05 | T3 | HIGH |
| CLM-0897 | The satellite aims its beam by listening for a low-power signal sent up from the receiving station, measuring the shape of that arriving wave and transmitting a time-reversed copy of it. The patent says in terms that this is what lets the structure be floppy. It is in the patent's claims, the part that sets what the patent protects, not just the explanatory text, and it stayed in the claims of the patent as granted, which was published in 2021. | VC05 | T3 | HIGH |
| CLM-0899 | The patent never says the steering signal is protected in any way. There is a difference between scrambling that signal so nobody can read it and signing it so the satellite can tell a fake from the real thing. Only the second would stop someone aiming the beam. The patent has neither. | VC05, XC04 | T3 | HIGH |
| CLM-0900 | The satellite can point its beam far further than there is Earth to point at, so moving power from one receiving station to another is not limited by the antenna. It is limited by other things, including whether a receiving station has been built there and whether that country has allowed it. | VC05, VC09, XC01 | T3 | HIGH |
| CLM-0901 | Each antenna must hold its position along the line to the receiver within about three millimetres for a tenth of a decibel. The whole 1970s design budget, converted to the same units, was 3.4 millimetres. One metre of structural bending is nearly three thousand degrees of phase, and if that is not corrected the antennas stop adding up at all - a billion of them lose ninety decibels, which is everything. | VC05 | T0 | HIGH |
| CLM-0903 | The shared clock tells every sensor to take its reading at the same moment. How precise that clock must be depends on how fast the thing being read is changing. If the reference tone is at the same frequency as the incoming signal, the reading changes only as the structure bends, and milliseconds are plenty. If the two differ by megahertz, the reading spins at megahertz too, and nanoseconds are needed. In the built prototype the two differ by 10 MHz, but it tracks the signal continuously and takes no separate readings, so this timing requirement does not arise there in this form. | VC05 | T0 | HIGH |
| CLM-0904 | Nothing the satellite distributes to itself is free. Each distributed signal reintroduces a small part of the error the steering trick removed, and the size of that part is just how far its frequency sits from the ground signal's. Two separate effects that looked unrelated turn out to be one rule. | VC05 | T0 | HIGH |
| CLM-0905 | Sharing a clock is not the same as being told what to do. The clock and the carrier tell the antennas nothing about where to send the power - that comes from the ground signal, and each antenna works it out for itself. If the shared signal fails, the beam does not go somewhere wrong, it stops being a beam. | VC05 | T3 | HIGH |
| CLM-0907 | No source held here gives a computed model of how a kilometre-scale structure of this kind bends: its modes and their shapes. Two separate calculations here both stop at the same point for want of it. Until somebody models that structure, both answers stay as ratios rather than numbers. | VC04, VC05 | T0 | MED |
| CLM-0908 | There are two different ways the scheme can fail and they are usually confused. One is that the structure has moved so far the satellite cannot tell which wave crest it is looking at. The other is that the values worked out between sensors are not accurate enough. The second gets better as the sensors get denser, but the first does not get better at all, so a well-sampled design runs into the first problem, not the second. | VC05 | T0 | HIGH |
| CLM-0910 | The problem of not knowing which wave crest you are looking at is solved by sending a second tone at a slightly different frequency. The beat between them repeats only every fifteen metres instead of every six centimetres, which is more than enough to tell the crests apart. Measuring the structure directly would also work, and needs about two hundred picoseconds rather than the ten that would be needed to do the whole job. | VC05 | T0 | MED |
| CLM-0911 | If the steering signal from the ground stops, the 1978 design's beam does not carry on pointing somewhere. It falls apart, and the power on the ground drops by a factor of about eight thousand, to below the Soviet guideline plotted in the report. The size of that drop turns out to match the number of independently steered pieces the antenna has, which suggests the same arithmetic could give a rough estimate for other designs. | VC05, VC06, XC01 | T3 | HIGH |
| CLM-0912 | How far apart the sensors may sit depends on how smoothly the structure bends, not on how big it is. The answer comes out as a fraction of the distance over which the bending stays similar to itself, and that fraction shrinks as the square root of how much the structure moves. Spacing them more than about 2.35 times that distance apart is worse than not correcting at all. To turn any of it into a number of metres somebody has to model how a two-kilometre structure actually flexes, and nobody here has. | VC05 | T0 | HIGH |
| CLM-0913 | When the satellite corrects its own bending by listening to the ground signal, what is left over is not how far the antennas moved. It is only the part of that movement the scattered sensors could not see. A structure that bows a metre smoothly, with sensors close enough to follow the bow, is barely affected; a millimetre of movement between sensors costs the full millimetre. If the frequency scaling is exact, the frequency of the ground signal drops out of the answer. | VC05 | T0 | HIGH |
| CLM-0915 | The leftover error does two different kinds of damage and they need separate budgets. A uniform tilt across the antenna does not weaken the beam, it moves it; everything else weakens it. Missing the receiver by 250 metres from geostationary orbit means pointing to about one and a half seconds of arc, and the steering system has to do somewhere between forty and a hundred and twenty times better than the structure can be pointed mechanically - depending on whether you take the whole structure or an individual sub-panel. | VC05 | T0 | HIGH |
| CLM-0916 | The built prototype gives every single antenna its own steering circuit rather than sharing one between a group. The steering signal arrives at one frequency, the power leaves at another 20 megahertz away, and a third frequency midway between them is piped to every antenna by cable as the common reference. The paper quotes two sets of these frequencies - what it designed for and what it actually measured, one megahertz apart - and taking one number from each set is how a reader gets the wrong answer. It kept the beam locked while the whole array was physically rotated. | VC05 | T2 | MED |
| CLM-0917 | Sensors placed too far apart do not merely help less. Past a certain spacing they make the beam worse than doing nothing, because each is reporting a bend that has nothing to do with the antenna it is being used to correct. That point is about two and a third times the distance over which the structure's bending stays similar to itself - not, as first drafted, one times it. | VC05 | T0 | HIGH |
| CLM-0918 | The 1978 study of what a solar power satellite would do to the radio spectrum found two things. Its transmitter NOISE would exceed what radio astronomy and deep space tracking are protected against. And its HARMONICS would breach recommendations and in one case the international regulations - though for the harmonics it said it could not make the comparison properly, because that figure had no bandwidth on its scale. It was a preliminary draft. | VC06, XC01 | T3 | HIGH |
| CLM-0919 | In 1978 there was no rule allowing a solar power satellite to transmit power, and the industrial band everyone assumed it would use permits unlimited power only on the exact frequency while separately forbidding the spurious and harmonic emissions the same report expects. A ground-based industrial heater interferes to the horizon; a satellite covers half the planet. | XC01 | T3 | HIGH |
| CLM-0920 | The 1978 study says a solar power satellite cannot keep its beam entirely on the receiving station - the physics of beams forbids it - so some energy reaches everywhere the satellite can be seen from. Most equipment is partly protected by its metal case and could be made to work with care. Microwave receivers are the exception it leaves open, because a receiver is built to be sensitive to exactly what is spilling; they could be modified, but nobody had worked out at what cost or how well. | VC06, XC01 | T3 | HIGH |
| CLM-0921 | The 1978 report says the power density a solar power satellite apparently needs to make economic sense was thought to be about the same as the density at which heating starts to produce irregularities in the ionosphere. So the design was thought to sit at that threshold, not below it, and the report says understanding of the interaction was not adequate to predict the severity of all its effects. | VC06, XC01 | T3 | HIGH |
| CLM-0922 | In 2001 a National Research Council committee found that the basic trade study for the solar array had never been done, and that the mass and cost of getting the array to orbit dominates whatever the array itself costs. Their summary is that making the array free would not fix it. | VC01, XC02 | T3 | HIGH |
| CLM-0923 | The 2001 committee says a solar power satellite several square kilometres across would need tens to hundreds of kilometres of cable in total, and that cable mass is one of the costs of using less efficient cells. | VC01, VC02 | T3 | MED |
| CLM-0924 | In four parts of NASA's programme the 2001 committee found an analysis missing or a goal without a stated basis: for solar arrays, for how much of the assembly work robots should do, for structures, and for thermal control. Reading these as one pattern, targets set before the study that would tell you what to aim for, is an inference; the committee makes each finding separately. | VC01, VC11, XC05 | T3 | MED |
| CLM-0925 | In 2001 the whole of American space solar-cell research - NASA, the Air Force and industry together - ran at about eight million dollars a year, against seventy-five million for ordinary ground solar cells at the Department of Energy. The same committee noted that space hardware is built in tiny quantities and tested heavily, while a power satellite would need millions of each part, and that the manufacturing investment NASA does not usually make might be where the biggest saving is. | XC05 | T3 | HIGH |
| CLM-0927 | The 1978 review found an interference route the report it was reviewing never considered: the power beam bouncing off rain, hail or blown sand into a ground microwave receiver that happens to share the frequency. It calculated the result and found it far above what international rules permit as unwanted signal. It also picked out the third harmonic, at 7350 megahertz, as the one most likely to cause trouble, because it lands in a government satellite band. | VC06, XC01 | T3 | MED |
| CLM-0928 | In 2011 an international study group said the last whole-system analysis of space solar power was done in 1997. The American National Research Council had already found the underlying studies missing in four technology areas in 2001. If these are the same gap, which is a reading and not something either body says, it was four years old when the NRC found it and still open ten years after that. | VC01, XC05 | T4 | MED |
| CLM-0929 | A search of the 2011 international assessment finds no power-density limit set by the ionosphere, and it mentions the ionosphere only twice in substance: once to say that tests from low orbit to the ground would be useful for understanding the beam's interaction with it, and once in a historical table of past experiments. The search used set terms and could miss a limit written in other units or other words. | VC06, XC01 | T4 | MED |
| CLM-0931 | A 1989 NASA workshop records that the receiving antenna on the ground is not just a receiver - it radiates too. One contribution lists harmonic radiation as a negative feature of the current design. Another reports that on a microwave-powered aircraft, by inference the Canadian SHARP aircraft that first flew on microwave power in 1987, the receiving antenna was noisy in three different ways, and that Canadian regulators nearly stopped the test flight over interference concerns. | VC06, XC01 | T3 | MED |
| CLM-0932 | A 2010 paper making the case for a national space solar power programme never works out a cost per unit of electricity, and its main system cost comes from an unpublished manuscript; one endnote does a rough fleet cost and return-on-investment sum. It also says the ionospheric and safety concerns look answered at a basic level, without giving a number. | XC01, XC02 | T4 | HIGH |
| CLM-0933 | In 1988 the leading experimenter listed three numbers side by side: the best efficiency physics allows for beaming power and converting it back, 76 per cent; an experimental figure, 54; and what a solar power satellite design assumes, 58 to 72. The design range is above the experimental figure, and its top end is close to the limit. | VC05, XC02 | T3 | MED |
| CLM-0934 | In 1988 the NASA centre running the work said the solar power satellite programme did not stop because the technology failed. It stopped because the up-front investment was more than American utilities would risk, and because the energy crisis ended. The same document reports that the centre's own three-year rectenna research at very high frequencies produced encouraging results and no working devices. | XC02, XC05 | T3 | HIGH |
| CLM-0935 | The IPCC's chapter on energy systems mentions space-based solar power once, in a single sentence, among a list of alternative solar technologies that includes solar chimneys. It says the concept takes advantage of continuous sunlight but faces a formidable obstacle: getting the power down safely, efficiently and cheaply. It gives it no cost, no potential figure, no table row and no section of its own. | VC05, XC02 | T3 | HIGH |
| CLM-0936 | The IAA's 2011 assessment says that enough solar power satellites to supply the whole world would warm the Earth by less than 0.006 degrees C. A footnote gives the full method, and redoing the sum with the source's own numbers gives 0.0062 degrees C, slightly more than the bound the sentence states. The same footnote's other figure, for a single satellite, does check out. So the method is sound and the word "less" is wrong: it should say about 0.006 degrees C. | XC03 | T4 | HIGH |
| CLM-0937 | A 2024 law review article quotes a 2011 assessment's figure for how much solar power satellites would warm the Earth. The assessment said "less than 0.006 degrees C". The article says the systems "would likely cause a 0.006 degrees C rise". Dropping "less than" turns a ceiling into a prediction, and it is not flagged as a change. Everything else about the citation is correct, and by luck the changed version is nearer the true figure than the original was. | XC03 | T4 | HIGH |
| CLM-0938 | A 1988 NASA paper says a rectenna built on mylar reached 85 per cent efficiency. The 1987 final report of the contract it cites says mylar managed 70 per cent, and that 85 per cent needed a different plastic. | VC07 | T3 | HIGH |
| CLM-0939 | The 85 per cent figure that later papers quote flat was one component on a bench, in moving air, with an error bar, at one power level. The array number beside it was an estimate, not a measurement. | VC07 | T3 | HIGH |
| CLM-0940 | Two NASA efforts to build rectennas at much higher frequencies than the standard 2.45 GHz ended without a working device. One concluded the approach it had chosen would not work; the other simply ran out without completing anything. | VC07 | T3 | HIGH |
| CLM-0941 | In space there is no air to carry away the waste heat, so a rectenna's output is limited by how much waste heat it can radiate. The report puts that ceiling at about 2.33 kW of DC per square metre. | VC07 | T3 | MED |
| CLM-0942 | Three documents held here give three different sizes for the same satellite's transmitting antenna. The patent says 1 to 1.5 km across and explains why. A 2026 paper says about 2 km by 2 km, citing someone else. A 2024 law review says 2 km across. The last two use the same number for different shapes, and a 2 km circle collects a fifth less than a 2 km square. | VC05 | T3 | HIGH |
| CLM-0944 | A 2024 legal article about the law of space solar power talks about radio spectrum exactly once, in half a sentence, and gives no source for it. It names the International Telecommunication Union, but as the body that allocates orbital positions - the word "frequency" is only part of the name of the ITU's mechanisms. Across all 308 pages of the volume the words bandwidth, GHz, MHz and Radio Regulations do not appear at all. | XC01 | T2 | HIGH |
| CLM-0945 | The article asks whether the orbital slot a solar power satellite sits in counts as a "space resource" under the Outer Space Treaty. If it does, the Treaty's rule that nobody may appropriate outer space applies to it. The authors argue orbit is finite because it is getting crowded, and that one country or company taking the best slots could amount to the exclusive control the Treaty was meant to prevent. | XC01, XC03 | T2 | HIGH |
| CLM-0946 | A rectenna under test emitted a spurious signal. The cause was the resistor they hung on its output, not the rectenna itself, and swapping the resistor made it stop. The diode's own harmonics were measured separately and plotted. | VC06, VC07, XC01 | T3 | HIGH |
| CLM-0947 | A 1982 Japanese review calculates that the ionosphere absorbs about one part in fifty thousand of a 2.45 GHz power beam - around 0.1 MW from a 5 GW beam. That is nothing to the power system. The same sentence says it is still enough to warm the E-region, especially at night. | VC06 | T3 | HIGH |
| CLM-0948 | The "space ready" rectenna was tested for surviving the rocket launch and fitting into its container. Its report describes no vacuum or heat testing. | VC03, VC07 | T3 | HIGH |
| CLM-0949 | There is a standard international curve describing how quickly an antenna's stray radiation should fall away off-axis. The SPS pattern stays under that curve everywhere except at its grating lobes - the repeating spikes caused by building the antenna out of subarrays - and the report says that because of those spikes the standard curve cannot be used to describe the SPS safely. | VC06, XC01 | T3 | HIGH |
| CLM-0950 | A solar power satellite in geostationary orbit cannot make its beam any tighter than its design figure, because it is too far away to focus more sharply. The same antenna in low orbit could concentrate the beam a thousand times harder, and what stops it is the air breaking down at about 45 km up rather than anything in the satellite. | VC06, XC01 | T3 | HIGH |
| CLM-0951 | The usual way to stop a strong transmitter interfering with other radio users is to smear its power across a wide band. For a solar power satellite the report calculates that the smear would have to be about 3200 GHz wide to satisfy the protection limit for microwave relay links - about 32,000 times the 100 MHz band the satellite would use. The beam is strong enough to overload a relay receiver even at frequencies well away from its own. | VC06, XC01 | T3 | HIGH |
| CLM-0952 | A solar power satellite would have to stay below published interference limits, and the limits differ by who is being protected. Microwave relay links get a limit per 4 kHz of bandwidth. Radio astronomy and deep space research get limits stated per hertz, which cannot be ranked directly against the relay limits. The radio astronomy and deep space limits are recommendations rather than binding rules, and the report says what protection radio astronomy really has is not clear. | VC06, XC01 | T3 | MED |
| CLM-0953 | The rectenna was squashed to fit its container, which spoiled the impedance match between it and the incoming beam. The report accepts this on two grounds: the mismatch protects the circuit from high power, and efficiency was not being measured anyway. | VC07 | T3 | HIGH |
| CLM-0954 | The 1975 designers worked out how much their kilometre-wide antenna would bend, precisely so they could decide how good the beam-steering correction had to be. The biggest bend came from building it slightly wrong in the first place - roughly three quarters of a metre to a metre and a half at the edge, depending on how the stated angle is read - and that does not move. Heat bending could be held to a few centimetres if the top and bottom of the truss were kept within four degrees of each other. | VC04, VC05 | T3 | HIGH |
| CLM-0955 | The earlier formula for how much beam error is left after interpolating between sparse sensors turns out to be pessimistic by somewhere between 20 per cent and a factor of three, when the structure is modelled as a handful of bending modes rather than as random roughness. So the sensor spacings it permits are on the safe side, by 10 to 70 per cent. | VC05 | T0 | HIGH |
| CLM-0956 | If the antenna structure bends by the amounts the 1975 design allowed for - millimetres to a few centimetres from heating - then sensors every 10 to 18 metres, which is the size of the building blocks it was made from, are far more than enough to keep the beam within its error budget. They would only become too sparse if the bending reached tens of centimetres. | VC04, VC05 | T0 | MED |
| CLM-0957 | The idea was to listen to the pitch of the reference signal at each antenna element, work out how fast that element is moving, and add it up to get where it is. It fails three ways: the pitch cannot be measured finely enough over the time the structure takes to move; the 1981 design's own timing system deliberately cancels exactly that pitch change at the element; and the reference signal travels along the structure, not along the beam, so it barely notices the bending the beam cares about. | VC05 | T0 | HIGH |
| CLM-0958 | What is left of the idea is useful but narrower: the timing system already tracks how the reference path stretches, and the fast part of that stretching is the structure's vibration. It cannot give the slow bending that the sensor-spacing question is about, but it could tell you how the vibration is shared between modes - which is the one thing the modelling could not settle. | VC05 | T0 | MED |
| CLM-0959 | The original 1975 calculation found the satellite's radio noise would be fine for ordinary and troposcatter radio links and a problem only for radio astronomy. The 1978 review that redrew its chart swapped the two "fine" limit lines for stricter ones and then listed troposcatter as a problem. The disagreement is over which limit to apply, not over the arithmetic. | VC06, XC01 | T3 | HIGH |
| CLM-0960 | The 1975 study found the satellite's harmonics - the multiples of its transmit frequency - would trouble radio astronomy at the second and third harmonic, would trouble ordinary radio only at the klystron's second harmonic unless a filter was added, and would be clear at the fourth. A later reading of a redrawn chart says all three harmonics exceed everything. The original does not say that. | VC06, XC01 | T3 | HIGH |
| CLM-0961 | Everything in the 1975 interference analysis is for one satellite. The study itself says that a hundred of them would raise the noise and harmonics a hundredfold - 20 decibels - and that nobody had looked at what that would mean. | XC01 | T3 | HIGH |
| CLM-0962 | The 1978 US government reference design assumed two satellites would be finished every year for thirty years. That was a starting assumption for the cost work, not something the study worked out. | VC11, XC02 | T3 | HIGH |
| CLM-0963 | The 1978 reference design expected each satellite to take six months to build in orbit, using a crew of roughly 550 to 700 people. Two figures in the same report disagree about how many of them were in low orbit. | VC11 | T3 | MED |
| CLM-0964 | To build two of these satellites a year, about 300 tonnes of material had to arrive at the orbital construction site every day. Getting it there was over a third of the whole cost. | VC10, VC11 | T3 | HIGH |
| CLM-0965 | In 1973 an astronaut on Skylab put together two long poles from short sections in just over two hours, about six minutes per join. A 1975 antenna study used that as its only real-world data point for how fast people can build things in space. | VC11 | T3 | MED |
| CLM-0966 | In 1975 the antenna alone was expected to take one to two years to assemble in orbit with about fifty people, and robot arms were judged cheaper than astronauts doing it by hand. | VC11 | T3 | MED |
| CLM-0967 | The 2022 European study assumed it takes two years to build a satellite in orbit, and that getting parts launched could be the thing that makes it take longer. | VC11, XC02 | T4 | MED |
| CLM-0968 | The 1975 antenna study worked out how hot the middle of the transmitter gets depending on how efficient the tubes are and how tightly they are packed. With the tubes at 70 per cent efficiency and an aluminium frame, it found they had to be spread almost evenly across the whole kilometre to stay within what the frame could take. | VC03, VC05 | T3 | HIGH |
| CLM-0969 | If the tubes are only 70 per cent efficient, the transmitter's own face is not big enough to get rid of the heat they make, even spread perfectly evenly. At 85 per cent it is comfortable. The tipping point is almost exactly the efficiency the 1975 study said its tubes achieved. | VC03 | T0 | MED |
| CLM-0970 | A 1992 computer model of the same thin-film receiving antenna, sitting in space with nothing but radiation to cool it, found its diodes would overheat well before the sheet itself ran out of cooling capacity. The usable power per square metre came out about nine times lower than the simpler sheet-only estimate. | VC03, VC07 | T3 | HIGH |
| CLM-0971 | The heat from each tiny rectifier can only escape downwards into the copper it sits on, because the two hair-thin gold wires on top barely conduct heat at all. That one-sided path, not the sheet's ability to radiate, is what sets the limit. | VC03 | T3 | HIGH |
| CLM-0972 | If you take a 1975 estimate of how fast people could build structure in space, checked against one Skylab task, and apply it to the 1978 design's framework, you get a crew of a few hundred to build it in six months, which is roughly what the design said. For the framework, the 1978 numbers add up. | VC11 | T0 | MED |
| CLM-0973 | Apply that same measured pace to the whole satellite rather than just its framework, and the 1978 design would have needed several thousand people, not a few hundred, to finish in six months. The design assumed something made people two to fourteen times more productive and never said what. | VC11, XC02 | T0 | MED |
| CLM-0974 | The 1978 reference design shows every loss between sunlight and the power grid as a chain of numbered boxes, and the boxes multiply out exactly: about 7 per cent of the sunlight hitting the satellite reaches the grid. A rival 1980 design from Rockwell does the same sum and lands within about one per cent of its own published answer. | VC01 | T3 | HIGH |
| CLM-0975 | Depending on which published assumptions you take, a satellite needs between about 2 and 6 square kilometres of solar blanket for every gigawatt it generates. Nearly all of that spread comes from how efficient the cells are; degradation and pointing each shift it by ten per cent or so, and the exact sunlight value by under one per cent. | VC01 | T0 | MED |
| CLM-0976 | In the 1979 Boeing design the machines that extrude the satellite's beams ran at 5 metres a minute, with about half an hour of fixed handling per beam segment, and the assembly line that laid beams and unrolled solar blankets together advanced at half a metre a minute. | VC11 | T3 | MED |
| CLM-0977 | In 1978 Boeing worked out how the timing reference should fan out across the kilometre-wide transmitter. The choice of how many branching levels to use was tied to how big each controlled patch of antenna could be and how tightly each level had to hold its timing: bigger patches need more levels controlled down to the individual tube, and each level then gets only two degrees of timing error at the reference frequency. | VC06 | T3 | HIGH |
| CLM-0978 | In 1979 Boeing wrote down where the timing errors in the transmitter would come from. Most of the allowance, about six of the seven degrees, went to the cables and waveguides carrying the reference around the structure; the electronics at each tube got about one degree each. | VC06 | T3 | HIGH |
| CLM-0979 | The three designs disagreed about what the guide signal from the ground should look like. One used a pair of tones either side of the target frequency; one used exactly the transmitter's own frequency and worried about telling the two apart; and by 1979 the reference design had moved to a coded, spread-out signal, the same family of technique that satellite navigation uses. | VC06 | T3 | HIGH |
| CLM-0980 | The company that designed the timing system in 1978 handled the bending of the transmitter by dividing it into groups of patches, each with its own small computer working out the correction from where the guide beam appeared to come from and where that group's elements actually were. How big a group could be depended on how much the structure bent. The report also shows how much cable length matters: two centimetres of mismatch between levels is about 58 degrees of error at 2.48 GHz but under two degrees at 70 MHz, and its remedy is to keep the cable lengths matched. | VC06 | T3 | HIGH |
| CLM-0981 | Smaller patches tolerate more bending: halving the patch from 10 m to 5 m doubles the allowed tilt for the same half-per-cent loss. A separate team found that a metre of bending is close to the limit of what a pointing sensor can tell apart, and that a pointing sensor can use at most three patches while keeping within an arc-minute of error. The tilt limit was set by the Soviet exposure standard at the first grating lobe. | VC06 | T3 | MED |
| CLM-0982 | The famous six months to build a satellite in orbit was decided first and the designs were fitted to it. One contractor says outright that it slowed its machines and cut its crew to make the number come out. | VC11, XC02 | T3 | HIGH |
| CLM-0983 | Rockwell's crew is around nine hundred because it runs three shifts round the clock with a fourth crew resting, and at any moment fewer than ninety of the two hundred-odd on shift are actually building the frame. The machine speed was assumed, not measured, and forty per cent was added for joints and downtime. | VC11 | T3 | HIGH |
| CLM-0984 | The programme's own arithmetic for the antenna frame: each beam takes its length divided by five metres a minute plus twenty minutes to handle, which comes to about three hours per bay, padded to four for downtime. | VC11 | T3 | HIGH |
| CLM-0985 | By 1981 the programme put about four hundred people at the orbital construction base, with roughly two-thirds of them on the actual building work and the rest running the base, each staying about ninety days. The prime contractor's 1979 plan for the same base had ten-hour shifts six days a week. | VC11 | T3 | HIGH |
| CLM-0986 | The beam-machine speeds in these studies were chosen off a curve, with the operating figure set where going faster stopped helping, and the five metres a minute used elsewhere was a planning assumption that the machine-builders thought could be doubled. | VC11 | T3 | HIGH |
| CLM-0987 | They built in high orbit not because it was cheaper - the 1978 numbers said low orbit was - but because a half-built satellite in low orbit gets pulled about by gravity gradients and drag, cools every time it passes into shadow, and cannot be flown up to high orbit in one piece without breaking. | VC10, VC11 | T3 | HIGH |
| CLM-0988 | The rule that radio astronomers hold the satellite to is a specific international report, and its limit near the satellite's frequency is 87 dB, about five hundred million times, below the noise the 1975 transmitter design would put on the ground. The rule also says nothing about noise just outside the protected bands, which is where most of a wideband transmitter's noise would fall. | XC01 | T3 | HIGH |
| CLM-0989 | The same figure, minus 160, appears in two 1970s papers meaning two different things: in one it is the noise reaching the ground, in the other it is the noise of a single tube compared with its own signal, which after adding up ninety thousand tubes and the distance to the ground comes out 27 decibels lower. Anyone quoting "minus 160" has to say which. | VC06, XC01 | T3 | HIGH |
| CLM-0990 | The extra twenty decibels of noise suppression for a fleet assumes a hundred satellites. The government's reference plan was sixty, which needs about eighteen decibels; the hundred was a convenient round figure that the workshop papers used and said so. | XC01 | T3 | HIGH |
| CLM-0991 | In 1978 the frequency band the satellite was to use was an industrial free-for-all band in the West, where users must put up with each other's interference, but the Eastern bloc had its equivalent band shifted 75 MHz lower, so the satellite's frequency was not inside it there. | XC01 | T3 | HIGH |
| CLM-0992 | The receiving field on the ground makes its own harmonics: the diodes that turn microwaves into electricity also generate signals at two, three and four times the frequency and send some of it back out. Early measurements put the strongest of these at about three hundred times weaker than the main beam. | VC07, XC01 | T3 | MED |
| CLM-0993 | Space Solar has won a 1.3 million pound research contract from the research agency ARIA to help solar-powered high-altitude aircraft keep flying through the winter at UK latitudes by beaming them microwave power from the ground, at 5.8 GHz, into an antenna built into the wing. The programme's goal is a few hundred watts to a small payload for a week at a time. | VC06, VC07, XC05 | T5 | HIGH |
| CLM-0995 | The whole ten-kilometre satellite was designed to sway once every fourteen minutes, and the antenna was required to be at least as stiff as once every ten minutes so that ordinary control could keep it pointed to a twentieth of a degree. | VC04, VC06 | T3 | HIGH |
| CLM-0996 | The beams the reference satellite would be built from are specified down to the wall thickness, and two contractors give the stiffness numbers. | VC04 | T3 | HIGH |
| CLM-0997 | The designers said how flat the antenna had to stay: within about half a metre overall, with the surface elements out of true by no more than a twelfth of a degree, under sunlight, gravity and a 24 degree temperature difference across the frame. | VC04, VC06 | T3 | HIGH |
| CLM-0998 | With the top of a five-kilometre section of the satellite two hundred degrees Fahrenheit hotter than the bottom, the estimate has its free end bending by about eight or about eighty metres during construction. The report's text says eight metres and its own chart says about eighty; the report does not say which is right. | VC03, VC04 | T3 | MED |
| CLM-0999 | Rockwell hung a small transmitter above the antenna to give every patch the same timing reference, and each patch corrected its own received timing back to what a perfectly flat antenna would see. | VC06 | T3 | HIGH |
| CLM-1000 | By 1981 the government's own compatibility study said the satellite's frequency band had not actually been allocated to it, listed which services each harmonic would land on, and concluded that radio telescopes could not work within about 150 km of a receiving site. | XC01 | T3 | HIGH |
| CLM-1001 | Besides the deliberate beam and the tubes' noise, the satellite's fifty square kilometres of warm solar array glow faintly at radio frequencies; the 1981 study put that glow at a level far below anything else and noted that the tube noise would change if magnetrons or other tubes replaced the klystrons. | VC06, XC01 | T3 | HIGH |
| CLM-1002 | The 1981 study tells you exactly which international rulebooks it measured the satellite against, report by report, and warns that the second harmonic lands in the working band of America's biggest radio telescope even though no rule formally protects it there. | XC01 | T3 | HIGH |
| CLM-1003 | For a transmitter built from millions of small solid-state amplifiers instead of tubes, the 1980 study worked its noise budget down to the ground and found about 27 decibels of headroom against the limit it used; it also noted that for such a large array the second harmonic's grating lobes miss the earth altogether, so the worry moves to the third harmonic, and that a separate frequency allocation for harmonics might be needed. | VC06, XC01 | T3 | HIGH |
| CLM-1004 | In 1980 the systems contractor's own table said magnetrons were about three billion times (95 dB) noisier than klystrons; a year later the same contractor was quoting the tube maker's claim that a magnetron run without its heater was quieter than a klystron, while also listing proper noise measurements as work still to be done. Anyone citing "the magnetron's noise advantage" from this period has to say whose figure it is. | VC06, XC01 | T3 | HIGH |
| CLM-1005 | The 1980 assessment explains where the 10 milliwatt limit came from: a heating threshold of 100 divided by a safety factor of ten. It also records that the limit had no enforcement teeth, that a new limit based on absorbed power per kilogram was being discussed, and that there was still no public limit at all. | XC01, XC03 | T3 | HIGH |
| CLM-1006 | In 1980, by the US assessment's figures, the Soviet limit for the general public was two thousand times lower than the American 10 milliwatt guideline. The 1978 American design's fence line was set at a level that would have been legal in Canada or the United States and twenty times over the Soviet public limit the assessment gave. | XC01, XC03 | T3 | HIGH |
| CLM-1007 | The 1980 assessment worked out that a full American deployment would raise the microwave background everywhere in the country to about twenty times what people were then typically exposed to, though it said the two could not be compared directly because the frequencies differ. It said a risk assessment had to be done before building. No such assessment is held. | VC07, XC03 | T3 | HIGH |
| CLM-1008 | The 1980 documents give the beam's strength at the satellite, on failure, and above and below the receiving panels. The summary and the detailed report disagree by about twenty times on how much reaches the ground under the panels, which is the number the conclusions about ground animals and plants rest on. | VC07, XC03 | T3 | HIGH |
| CLM-1009 | The 1980 programme tested bees because of pollination. Early results showed no effect at the beam's strength, and one preliminary report found no effect on bees finding their way home at more than twice the beam's peak. None of this was finished or published at the time. | XC03 | T3 | MED |
| CLM-1010 | In the US Department of Energy's 1980 assessments the only bird numbers were from quail eggs at a fifth of the beam's peak, which hatched normally with minor blood changes. The assessments described the programme's preliminary bird report as mainly about design and facility building. The idea that flying birds would overheat in the beam was stated as a worry, not a finding. | XC03 | T3 | MED |
| CLM-1011 | In 1980 the programme used two different rules to translate its low-frequency experiments to the real beam, one for heating and one for the instability. It said the rules were believed sound, and in the same document that the instability rule had never been tested. | VC06, XC03 | T3 | HIGH |
| CLM-1012 | In the DOE's 1980 summary the Platteville heating tests showed no effect on the navigation and broadcast radio it listed at the beam's equivalent strength (a separate 1980 report on the trials records cross-modulation on time-signal stations and one AM station), warmed the lower ionosphere by roughly the amount theory predicted, but did not produce the density change the same theory predicted. The programme concluded 23 was safe for these systems and said bigger facilities were needed to find the ceiling. | VC06, XC03 | T3 | HIGH |
| CLM-1013 | By 1980 the programme had made the upper ionosphere ripple with a heater running at what it reckoned was four to twelve times the beam's strength, and seen satellite signals flicker as a result, while a radar looking for the same ripples saw nothing. Whether any of this applied to the real beam depended on a scaling rule nobody had tested. | VC06, XC03 | T3 | MED |
| CLM-1014 | The 1980 programme did the sums on what four hundred heavy launches a year would do to the upper air: a lot more water high up, a big local rise in nitric oxide from re-entries, and an ozone change too small to measure either way. Its own two volumes disagree by five times on the ozone offset from re-entry, and the later one expected the sign to flip. | XC03 | T3 | HIGH |
| CLM-1015 | The 1980 assessment expected each big orbit-transfer burn to punch a hole in the upper ionosphere the size of the continental United States, once or twice a month, with smaller daily holes from the launcher, and a permanent thinned ring around the launch latitude. It could not say what that would add up to. | VC06, XC03 | T3 | MED |
| CLM-1016 | The 1980 programme expected heavy launches to change local weather in small ways, to produce a ground cloud like a dirty coal plant's for a short time, and to make thin high clouds, and it labelled nearly all of its own results tentative. | XC03 | T3 | MED |
| CLM-1017 | By 1981 the programme itself said the ionospheric limit it had designed to was probably too cautious, and worked out what relaxing it to more than double would be worth: nearly twice the power from a slightly larger antenna, at a third of the cost penalty. | VC06, XC02, XC03 | T3 | HIGH |
| CLM-1018 | Three years of study left the efficiency chain exactly where 1978 put it, and Boeing's own version says out loud the solar constant the 1978 figure only implied. | VC01, VC06 | T3 | HIGH |
| CLM-1019 | The programme gave three reasons for choosing the klystron; the company that designed the satellite said the choice was more or less arbitrary and the magnetron might be better. The 85 per cent tube efficiency that every cost chain uses is the contractor's estimate. | VC05, VC06 | T3 | HIGH |
| CLM-1020 | By 1981 the programme was confident the beam could be pointed and formed, and named the network that carries the timing reference across the transmitter as the part it was least sure of, with the choice between cable, fibre and a broadcast reference still open. | VC06 | T3 | HIGH |
| CLM-1021 | Boeing ran the timing reference down glass fibre in four stages, measured each fibre's delay by sending the signal back, and used a second tone at half the frequency to tell which cycle it was in - the same trick satellite navigation uses. Every one of the hundred thousand tubes got its own phase corrector. | VC06 | T3 | HIGH |
| CLM-1022 | A loss you can make up by adding solar panels costs about 56 million dollars per percentage point; a loss at the ionospheric ceiling costs eleven times that, because there is no more beam to give. That is why the ionospheric limit matters economically, and it is the first price on the timing-error budget. | VC06, XC02 | T3 | HIGH |
| CLM-1023 | The programme's last word on its rockets describes a launcher of about 11,000 tonnes at liftoff flying about once a day, gives fleet sizes and turnaround times, deliberately gives no costs, and ends by recommending a launcher with a quarter to a third of the payload. | VC10 | T3 | HIGH |
| CLM-1024 | The 1979 government estimate put a heavy-lift flight at about ten million dollars of the day, most of it people refurbishing the vehicle, which works out at about thirty 1979 dollars for every kilogram put into low orbit. That is the number the programme's later cost goal was built on. | VC10 | T3 | HIGH |
| CLM-1025 | In 1980 the people building the case set themselves a goal of thirty dollars a kilogram to low orbit, hoped for fifteen later, and said in the same breath that the programme's schedule could not be met. | VC10, XC02 | T3 | HIGH |
| CLM-1026 | The electric ferry takes half a year to climb to geostationary orbit but burns about an eighth of a kilogram of argon for every kilogram it carries; a chemical stage would burn two kilograms of propellant per kilogram and need almost three hundred trips per satellite. That ratio, not speed, is why the programme chose electric. | VC04, VC10 | T3 | HIGH |
| CLM-1027 | Getting a crew from low orbit up to the construction site took half a day and a stage the size of a small airliner, refuelled at the top with fuel the slow electric ferry had carried up. Counted fully, moving one worker's year of labour into orbit cost about a million 1977 dollars. | VC10, VC11 | T3 | HIGH |
| CLM-1028 | Building the rockets was priced at seventeen billion 1977 dollars and running them at about 2.8 billion per satellite, or roughly sixty 1979 dollars for every kilogram of satellite delivered to its final orbit. Most of that was the launcher; the electric ferry was a fifth. | VC10, XC02 | T3 | HIGH |
| CLM-1029 | In 1980 the programme's own accounting had rockets at roughly one dollar in four of a satellite's cost and nearly one in two of the money needed to develop the system, and it noted that the whole programme through the first satellite cost about what NASA had spent from its founding through Apollo. | VC10, XC02 | T3 | HIGH |
| CLM-1030 | The independent 1980 cost review said the government's rocket numbers were fair for the stage the programme was at, then added spare vehicles because the plan assumed nothing would ever fail, roughly doubled the risk on the electric ferry because its unit price assumed a factory that did not exist, struck out the dedicated crew launcher, and put the running cost about eleven per cent higher with a much wider error band. | VC10, XC02 | T3 | HIGH |
| CLM-1031 | A launcher a third the size of the reference one would cost about a fifth more per kilogram to fly and need four launches a day instead of one, but would save five billion dollars up front and add only three per cent to the cost of each satellite. By 1981 everyone involved wanted it. | VC10 | T3 | HIGH |
| CLM-1032 | If the ferry's solar cells could not be repaired in flight it would wear out in three trips and the cost per kilogram would rise by about a third; thicker glass would fix that. A ten-minute delay restarting the engines every orbit cost more than the heat of being near Earth, and a chemical ferry would cost twice as much. | VC04, VC10 | T3 | MED |
| CLM-1033 | At the higher of NASA's two peak figures, the launches would have needed about 6 per cent of US daily hydrogen output and 30 per cent of its oxygen, and making the hydrogen by splitting water would have consumed about half the output of one of the satellites being launched. NASA's own report gives two different figures for how much fuel that is. | VC10, XC03 | T3 | MED |
| CLM-1034 | The programme's transportation workshop said the schedule was probably unrealistic, and the programme's cost reviewer said the launcher fleet was too small for it: about one launch a day on a five-and-a-half-day turnaround with no reserve vehicles, and a fleet of slow electric ferries with no slack for accidents. | VC10, VC11 | T3 | HIGH |
| CLM-1035 | In 1981 NASA priced a satellite at 11.5 billion 1977 dollars and the road to the first one at 102 billion, said it was not an official figure, and built the transport line on a launch price that works out at about 24 of those dollars per kilogram to orbit. | VC10, XC02 | T3 | HIGH |
| CLM-1036 | The programme's own sizing arithmetic, with its rate of return stated: in the cases studied a bigger antenna always raised the cost, but much less if the ionospheric limit rose with it. The 152.3 in its cost formula is the capital-recovery factor for 15 per cent over thirty years. | VC06, XC02 | T3 | HIGH |
| CLM-1037 | By the end of 1980 the programme office was saying in writing that its own design limit was too cautious, that fifty or sixty might be reasonable, and that the cost case depended on raising it. | VC06, XC02, XC03 | T3 | HIGH |
| CLM-1038 | In 1980 the Department of Energy calculated that a silicon space solar satellite would take six years to pay back the energy that built it, four times longer than coal or nuclear, and that almost all of that was the energy cost of making the silicon cells; with gallium arsenide cells it was a little over a year. | VC01, XC02, XC03 | T3 | HIGH |
| CLM-1039 | The programme's own military studies did not treat the beam itself as a real weapon. The 1980 study said one captured beam would carry rather little power and has no known harm to living things, so at most it might be used to frighten people, as the 1978 study also suggested. Twenty satellites pointed at one spot would reach 3.3 times the sunlight figure the study used, which is about the strength of sunlight above the air; that is about 4.6 times standard sunlight at the ground. What the studies worried about was the lasers a satellite could power, and someone faking the pilot signal, for which they listed the countermeasures. | XC04 | T3 | HIGH |
| CLM-1040 | The programme's first military study said the satellite could not be fully protected; its second said it was no softer a target than a power station or a refinery, that it could not be made to fall on anyone, and that the one real threat was the electromagnetic pulse of a nuclear detonation in space. | XC04 | T3 | HIGH |
| CLM-1041 | In 1978 the programme's lawyer said nobody can own a slot but anyone can use one, sunlight in orbit belongs to everyone, the ITU allocates frequencies but not slots, and if the beam hurt someone there was already a treaty to claim under. | XC01 | T3 | HIGH |
| CLM-1042 | In 1978 a programme lawyer noticed that a power beam carries no message, so the ITU's rulebook did not obviously cover it, and found the ITU's way in was through interference with everyone else. | XC01 | T3 | HIGH |
| CLM-1043 | With the heater off and a tuning circuit on the cathode, one hand-picked oven magnetron was as quiet as the instrument could measure: about 197 decibels below its carrier per hertz of bandwidth, 50 megahertz away from the carrier. Detuning the cathode circuit cost 20 decibels; turning the heater on swamped the display. | VC06, XC01 | T3 | HIGH |
| CLM-1044 | In 1980 the quiet oven magnetron was already beyond the instrument's reach: at least 155 decibels below carrier per hertz away from the carrier, quieter at low magnetic field and high current, unaffected by drive level. Close to the carrier its added phase noise was about 114 decibels down per kilohertz at 50 kilohertz. | VC06, XC01 | T3 | HIGH |
| CLM-1045 | Raytheon's own numbers had the klystron just failing the interference limit at the band edge and the magnetron clearing it by 45 decibels, while conceding nobody had measured a klystron that close to its carrier and that near the carrier the klystron was slightly quieter. | VC06, XC01 | T3 | HIGH |
| CLM-1046 | The number Raytheon wrote into the design table for the satellite tube was about fifty times noisier than its best laboratory reading, because it did not yet know where the noise came from; the only work on that question was Raytheon's own unfunded research. | VC06, XC01 | T3 | HIGH |
| CLM-1047 | The oven magnetron's second harmonic came out about 70 decibels below its carrier, a tuned stub took another 40 off, and the antenna's own pattern was credited with 65 more, so Raytheon reckoned the whole satellite's second harmonic would arrive on the ground fifty decibels under the limit. The third, fourth and fifth were measured but never filtered, and the fifth was unexpectedly strong. | VC06, XC01 | T3 | HIGH |
| CLM-1048 | A cheap oven magnetron run cold and hard converted 81.7 per cent of its DC input to microwaves, measured carefully by heating water. Raytheon's point was that theory said 94 and a lower-frequency tube already did 93, so the 2.45 GHz tube was leaving six points on the table nobody had explained. | VC06, XC01 | T3 | HIGH |
| CLM-1049 | The fifty-year magnetron rests on a cathode that runs cool because the tube heats it only as much as it needs, on tube-life curves from 1950s transmitter valves, and on twelve radio-station valves that ran ten years without failing. No magnetron had been life-tested that way, and the test tubes Raytheon looked into poisoned themselves in under an hour. | VC06, VC12 | T3 | MED |
| CLM-1050 | The interference limit Raytheon measured its tubes against is given as a CCIR requirement but never traced to a CCIR document, and one page even gets its units wrong by a factor of a thousand. | XC01 | T3 | HIGH |
| CLM-1051 | The DOE studies compared space solar against six power-station types picked by stated rules; ground-based solar cells were put in specifically to be the like-for-like comparison, and fusion because DOE was spending heavily on it, not because it would be ready. | XC02, XC03 | T3 | HIGH |
| CLM-1052 | In 1980 the programme's own numbers had a receiving site of about 200 square kilometres per satellite once a safety margin was included, roughly the same land per unit of energy as ground solar of the day and far more than a coal or nuclear plant, but with no mines or waste sites behind it; and the authors said not to add the columns up. | XC02, XC03 | T3 | HIGH |
| CLM-1053 | The programme's 1980 climate study counted only what the rockets and power plants emitted in use, found the launch carbon small next to coal, flagged rocket water vapour in the stratosphere as the open question, and said the science was not good enough to decide anything on. | XC03 | T3 | HIGH |
| CLM-1054 | The programme reckoned a receiving site would give off about as much heat per square metre as a suburb, a tenth of what the sun puts into the ground, enough for a degree of local warming in still air; one of its two reports prints the figure a hundred times too small, and the climate report suspects that the structure's roughness and reflectivity matter more than the heat. | VC07, XC03 | T3 | MED |
| CLM-1055 | The programme's 1980 look at nuisance and property effects gave space solar its worst marks on six counts, mostly because nobody knew enough about it, and said so. | XC03 | T3 | HIGH |
| CLM-1056 | Measured in expected deaths per year for a big power station's worth of electricity, the programme found coal far the worst and everything else, including space solar, about equal within the error bars; space solar's risk sat in building it, not running it, and its open questions were long-term microwave exposure and a rocket coming down on a city. | XC03 | T3 | HIGH |
| CLM-1057 | The safety study's own picture of the system: about $13 billion of hardware per satellite in 1978 money, 640 people in orbit for six months to build each one, forty heavy launches per gigawatt, a launch site loud at six kilometres and windows rattling at 125, and one rocket failure that could kill a thousand. | VC10, VC11, XC02 | T3 | HIGH |
| CLM-1058 | The often-repeated claim that the magnetron is 188 decibels quieter than its carrier traces to a conference abstract in which the tube maker said "180 to 190" for hand-picked tubes and said his instrument could not see below that outside a 60 megahertz window. | VC06, XC01 | T3 | HIGH |
| CLM-1059 | By spring 1980 the engineers, the reviewing panel and the ionosphere experimenters were all saying the beam-intensity ceiling the whole design hung on was too cautious; the table that priced relaxing it was published then, and reprinted unchanged in the 1981 summary. | VC06, XC02, XC03 | T3 | HIGH |
| CLM-1060 | The 1980 review did not agree with itself on how much of a satellite's cost was rockets: one paper said over a third, the programme's own table said a quarter of each satellite but nearly half of the money to get to the first one, and one paper's launch rate was double everyone else's. | VC10, XC02 | T3 | HIGH |
| CLM-1061 | In one 1980 volume the satellite cost anywhere from about 2,300 to 3,800 dollars a kilowatt depending on who added what - and the programme office said in print that none of it was official. The high-side cases, as printed, ran to four or five times the base, and one of those printed values may be a total carried into the wrong row. | XC02 | T3 | HIGH |
| CLM-1062 | In 1980 the launch vehicle that everything was costed on was said by its own designers to be arbitrarily big, and they proposed a rocket a third the size that would save five billion dollars up front for a three per cent higher running cost. | VC10, XC02 | T3 | HIGH |
| CLM-1063 | In 1980 the magnetron satellite was the lightest per kilowatt on paper and the most efficient tube on the bench, the klystron was the panel's safer bet on noise and voltage, and the panel warned that every efficiency budget so far used the most optimistic number for the tube. | VC05, VC06 | T3 | HIGH |
| CLM-1064 | The best transistor anyone had measured in 1980 was 72 per cent efficient at one watt and 60 per cent at five; the satellite designs assumed 80, and were heavier than the tube designs. | VC05, VC06 | T3 | HIGH |
| CLM-1065 | By spring 1980 the programme had decided to steer the beam tube by tube, having costed the extra hundred thousand receivers at under six hundred dollars each, and had tightened the amplitude tolerance about 26-fold in power (12-fold in voltage); its own review panel would rather have closed the loop from the ground. | VC06 | T3 | HIGH |
| CLM-1066 | Bees exposed for half an hour at up to twice the beam's peak came home and hatched about as well as unexposed bees; small birds sat through the beam's peak intensity with little more than occasional open beaks, less fluffing of feathers and possibly more resting, and a preliminary estimate put the level that would kill half of resting birds in winter at about six times that intensity. | XC03 | T3 | MED |
| CLM-1067 | The one primate experiment that looked alarming in 1980 - over half the infants dying in the highest-exposure group - did not repeat when rerun with more animals; the reviewer of the rodent work argued that a pregnant woman might absorb far less than the rats did, but that male fertility was the harder question. | XC03 | T3 | MED |
| CLM-1068 | The 1979-80 heating experiments warmed the lower ionosphere's electrons by a factor of up to about two to two and a half. Theory predicted it would thin by up to half low down and thicken by up to a fifth higher up. The navigation and broadcast signals passing through showed nothing anyone could measure. | VC06, XC03 | T3 | HIGH |
| CLM-1069 | Each launch would put about ten tonnes of nitrogen dioxide into a cloud over the pad, enough to breach a one-hour air standard on a bad day but not on its own, and make a shower of rain about as acid as ordinary polluted rain; the programme's own papers disagreed whether that happened 375 or 500 times a year. | VC10, XC03 | T3 | MED |
| CLM-1070 | Nobody in 1980 agreed whether the ion engines' argon would be caught by the earth's magnetic field or escape: one group had most of it caught within twenty seconds, another had all but a few per cent escaping, and the third had a sixth raining back into the atmosphere. | VC10, XC03 | T3 | MED |
| CLM-1071 | Running the programme at full stretch was reckoned to employ about half a million people on the ground, nearly all of them in factories, with roughly a thousand in orbit at any moment. | VC11, XC02 | T3 | HIGH |
| CLM-1072 | In 1980 the radio astronomers expected to lose a twenty-degree circle of sky around the satellites and two of their bands, the spectrum managers found the beam's skirts spilling into the neighbouring broadcast band and its third harmonic into a government satellite band, and the military found the transmitter's hundred thousand tubes would together hiss over a five-hundred-kilometre radius. | XC01 | T3 | HIGH |
| CLM-1073 | A satellite flying through the beam would get a few seconds of noisy pictures and garbled data and then recover; with a hundred satellites up, one would cross a given beam about monthly; and the rectennas would have to keep fifty to a hundred and fifty kilometres from observatories, radar ranges and airports. | XC01 | T3 | MED |
| CLM-1074 | One set of 1980 papers said each satellite would look like Venus and sixty of them like a slim moon; the contractor who actually worked the geometry said ten times Venus, with the transmitter flashing as bright as a full moon for two minutes at the equinoxes unless the panels were tilted or roughened. | XC01, XC03 | T3 | MED |
| CLM-1075 | Keeping the satellite on station against sunlight pressure was reckoned at eight per cent of its mass in argon over thirty years and 34 megawatts of its power; the antenna had to stay flat to half a metre across nearly two kilometres; and the review panel said confidence in all this rested on hope rather than evidence. | VC04 | T3 | HIGH |
| CLM-1076 | In 1980 the electronics that would condition the satellite's power weighed, at the state of the art, more than the whole satellite was allowed to; the design needed them fifty times lighter, and the arrays to run at fifty times the voltage anyone had flown. | VC01, VC04 | T3 | HIGH |
| CLM-1077 | The ground station was seven million panels holding thirteen billion little antennas, costed at about two and a half billion dollars, about 1.7 million tonnes of steel and nearly seven million cubic yards of concrete, and built by three thousand people in two years. | VC07, XC02 | T3 | HIGH |
| CLM-1078 | Put on stilts in fifty metres of North Atlantic the 1980 rectenna cost fourteen times its land price; strung from cables without its ground screen it came down to about twice, and Europe had a dozen shallow patches of sea to put one in. | VC07, XC02 | T3 | MED |
| CLM-1079 | The one outside firm asked to audit the 1980 cost estimates found the ground-station civil works priced at a third to a fifth of what construction experience said, the solar cells three to thirty times too cheap, and the slip rings ten to twenty times, and said the whole thing assumed breakthroughs it could not count on. | XC02 | T3 | HIGH |
| CLM-1080 | On the utilities' usual accounting the 1980 satellite could not beat coal or nuclear; on Boeing's whole-life accounting, which counted forty years of fuel, it cost less than half as much; and the economists said either way it would soak up a tenth to a quarter of the country's growth capital. | XC02 | T3 | HIGH |
| CLM-1081 | The people who would have to buy the power said in 1980 that a five-gigawatt block that could vanish within minutes in the spring and autumn eclipse periods might need six gigawatts of standby, that the ground station would lose two hundred thousand diodes a year, and that American utilities were unlikely to own one until there were some ten. | VC08, XC02 | T3 | HIGH |
| CLM-1082 | Two-fifths of the lower forty-eight states were nominally open to ground stations and sixty of them could be placed near the cities they served; the gallium for one satellite was sixteen times the world's yearly output; and the ground-station dipoles would come off the line at six hundred a second. | VC07, XC02 | T3 | HIGH |
| CLM-1083 | Building and keeping sixty satellites was reckoned at fifty thousand working years in orbit, mostly at geosynchronous altitude where the radiation is worst; a preliminary estimate expected that a five-year career there might raise a worker's cancer risk by about an eighth, and nobody knew what heavy cosmic-ray ions would do to eyes. | VC11, XC03 | T3 | MED |
| CLM-1084 | When the programme asked the public in 1979-80, one respondent in seven wrote back; the environmental and consumer groups were mostly against, the students split, the space enthusiasts for, and most people had never heard of it. | XC04 | T3 | HIGH |
| CLM-1085 | By 1980 both contractors' satellites had grown about 2.3 to 3.5 times heavier per kilowatt than the 1974 sketch; the gallium arsenide cell assumed for 1990 was two points above the best in any laboratory, and the silicon array would lose almost a third of its output in thirty years unless it could be annealed in orbit. | VC01 | T3 | HIGH |
| CLM-1086 | The number 2.45 GHz has a birthplace: a 1975 study for NASA that swept frequency from 1 to 5 GHz against cost, found a broad flat region near 2 GHz, and picked the industrial band sitting in it. The atmosphere was checked separately and found nearly transparent below 3 GHz. | VC06, XC01 | T3 | HIGH |
| CLM-1087 | When the programme wrote down why it used 2.45 GHz, its reasons were consistent: each time it named the industrial band and how the beam passes through the atmosphere, and some documents added rain, good efficiency, antenna size or the outlook for the equipment. | VC06, XC01 | T3 | HIGH |
| CLM-1088 | By 1980 the programme remembered its first study as having picked 2.45 GHz. The first study's report says it picked 3.3 GHz. The 2.45 GHz decision was made three years later. | XC01 | T3 | HIGH |
| CLM-1089 | The higher industrial band would have shrunk the receiving field to a fifth or a third of its size, at the price of a satellite that could not shed its heat, a bigger electricity bill, and a beam that rain could knock out. Every time the programme costed it the answer was the same and 2.45 GHz stayed. | VC06, VC07, XC01 | T3 | HIGH |
| CLM-1090 | The programme's two printed tables of how much beam the weather eats do not agree. One has the ionosphere numbers the wrong way round, and its rain and hail figures are a million times too small for the unit printed over them. The other is internally consistent. | VC07, XC01 | T3 | HIGH |
| CLM-1091 | The people running the programme said 2.45 GHz was sensible and also said, in the same breath, that nobody international had agreed to it and the choice was open. Their own account of the 1979 world radio conference is that no frequency was given and one might be, if the environmental case were made. | XC01 | T3 | HIGH |
| CLM-1092 | The famous 23 milliwatts per square centimetre is measured face-on to the beam, which is how the receiving panels are tilted, and is the same number the beam carries through the upper atmosphere. Spread over flat ground at the reference site in the southern United States, where, if the satellite is due south of the site, the beam comes in at about 50 degrees above the horizon, the same beam delivers about a quarter less per square metre of ground, 17 to 18 rather than 23. | VC06, VC07 | T0 | HIGH |
| CLM-1093 | Working the 1978 antenna design forward gives 25 mW/cm2 straight down from the satellite. The report prints 23. That drop can be explained by the extra distance to a site in the southern United States, or by the report's own allowance for phase errors and failed tubes, but not by both, and each explanation alone is worth the same 7 per cent. The report's own labelling suggests the errors were included, in which case the figure at the actual site is about 21.5. | VC06, VC07 | T0 | MED |
| CLM-1094 | The 1978 Rice report the archive holds is the follow-on to the 1977 one that the reference system cites, and the 1977 report, obtained the same day, gives about 20 milliwatts per square centimetre with no band and no derivation. The 12 milliwatts per square centimetre figure is worked out in the 1978 report from a simple heating-versus-cooling balance, and the authors say their simplifications make the real threshold higher, not lower, and that nobody had observed the effect. | VC06 | T3 | HIGH |
| CLM-1095 | The three harmonic numbers the register has carried since the 1978 conference paper come from one rectenna element on a bench at five watts, measured at its input with the antenna replaced by a matched line; the fourth is the meter's floor, not a reading. Filters and a metal shield on the element cut the second and third by 25 and 15 decibels. | VC07, XC01 | T3 | HIGH |
| CLM-1096 | In 1977 one rectenna element converted 90 per cent of eight watts of microwaves to DC but only 80 per cent of fifty milliwatts, and the report says why: at low power the diode's own losses dominate. The 85 per cent the programme wanted at low power was not reached. | VC07 | T3 | HIGH |
| CLM-1097 | By 1976 a rectenna had delivered thirty kilowatts over a mile at 82 per cent, a certified bench system had turned DC into microwaves and back at 54 per cent, and 199 elements had run four months without a failure, which the maker converted into a 27-year mean time between failures at 90 per cent confidence. | VC07 | T3 | HIGH |
| CLM-1098 | The 1977 plan for a cheap rectenna was two flat planes, the front one doing all the work inside a metal shroud that is also the structure, wired in series to reach a thousand volts for the inverters; a five-element piece was built and worked, and the report says the next thing to build is a thousand-volt section. | VC07, VC08 | T3 | HIGH |
| CLM-1099 | Boeing's 1977 sum gave the ground receiver 85 per cent, said it was probably a little low, and drew the trade that sets a rectenna's size: spreading the power evenly across the transmitter needs the smallest transmitter but wastes the most power outside the receiver's edge, and tapering the power towards the transmitter's edge makes the transmitter bigger and wastes less. | VC06, VC07 | T3 | HIGH |
| CLM-1100 | Boeing thought the receiving elements could be spaced almost twice as far apart as Raytheon's, halving their number, and that the receiver might lie flat on the ground rather than tilted at the satellite, but said the rectenna had had little attention and both ideas needed analysis. | VC07 | T3 | MED |
| CLM-1101 | Lightning will hit a ten-kilometre receiver often, so Rice designed a grounded conductor into its structure at every bay, costing under one per cent of the collecting area; a single diode survives an ordinary strike, but the forty-thousand-volt strings they are wired into do not, and need the same surge protection as any transmission line. | VC07 | T3 | HIGH |
| CLM-1102 | The receiving station the siting maps were drawn for is an oval twelve kilometres wide and, in the middle of the United States, sixteen long once its safety margin is added, about 150 square kilometres, with two and a half million panels on it; further north it gets longer because the satellite sits lower in the sky. | VC07, XC03 | T3 | HIGH |
| CLM-1103 | Mapped at the scale of one receiver per cell, two-fifths of the country was not ruled out; look closer and seven in ten of those cells fail too, mostly on terrain; take out farmland and a quarter is left. The study still found enough room in every region, with the caveats that its own numbers imply. | VC07, XC03 | T3 | HIGH |
| CLM-1104 | The siting maps kept receivers 150 km from radio telescopes, 100 km from NASA's deep-space stations, 60 km from air traffic radars and 50 km from nuclear plants, on asserted distances; because those places are mostly excluded for other reasons too, the electromagnetic rules only cost about seven per cent of the country. | VC07, XC01 | T3 | MED |
| CLM-1105 | The first look, in 1978, used a coarser grid and a bigger site than the 1980 study, ruled out half to five-sixths of the country depending on how many rules were applied, and declined to name sites; three million acres is a small fraction of America but a tenth of its cities. | VC07, XC03 | T3 | HIGH |
| CLM-1106 | The satellite's dark side charges to thousands of volts in the geostationary plasma, and the plastic backing of the solar cells would hold a few thousand volts across itself, within a factor of two of breaking down; the study's fix was a more conductive backing or a bleed path. | VC01, VC04 | T3 | MED |
| CLM-1107 | The actual Grid Code figure is not a flat 0.95 power factor at all voltages: the plant must push reactive power out when the grid voltage sags towards 0.9 and absorb it when the voltage rises towards 1.1, and full capability both ways is only demanded in a narrow band around nominal. At part load the requirement is a third of rated power either way, easing on the absorbing side below half load. | VC08 | T1 | HIGH |
| CLM-1108 | After the first 140 milliseconds, the rule is a line on a chart: the lower the grid voltage sags, the shorter the time the plant must hold on, from 0.14 seconds near a full collapse out to three minutes at a 15 per cent sag. Then it has to be back to 90 per cent output within a second of the voltage recovering, and stay on for half an hour. | VC08 | T1 | HIGH |
| CLM-1109 | The rulebook says the same as the guidance: nobody has to make their inverters behave like a rotating machine, but the grid needs enough plants that do, and it pays for them. If a plant offers it, it must be able to run into a dead network, feed its full rated current into a short circuit for the fault-clearing time, and be tuned within a stated damping range. | VC08, VC09 | T1 | HIGH |
| CLM-1110 | The best near-infrared laser-to-electricity receiver so far turns 56 per cent of the light into electricity, but only when the light is 271 kilowatts per square metre, a thousand times brighter than the microwave design beam. At the level the authors call eye-safe, about 270 times lower, it turns about 30 per cent into a couple of milliwatts, while also carrying gigabit data. | VC07, XC02 | T1 | HIGH |
| CLM-1111 | Before this paper, the best near-infrared laser receivers reached about half efficiency, and only under very bright light; at gentler light they manage a fifth to a bit under a half. Receivers for shorter-wavelength light do better, nearly 69 per cent, but the paper prefers the near-infrared band on eye-safety and atmospheric grounds. | VC07, XC02 | T2 | MED |
| CLM-1112 | The paper says this colour of infrared is good because the air lets it through and the eye-safety rules allow more of it, but it cites other papers for both and never gives a number for either. | VC07, XC01 | T1 | HIGH |
| CLM-1113 | This paper does not describe a laser power satellite, though two NASA-funded designs for one exist from 1978-80. It does show how a laser receiver behaves: it needs light about a thousand times brighter than the microwave beam to work well, and even at the level the authors call eye-safe it is about a third as efficient as the microwave receiver. | VC07, XC02, XC04 | T0 | MED |
| CLM-1114 | The 1977 silicon design assumed an 18 per cent cell that did not yet exist, doubled the sunlight on it with cheap plastic mirrors, and got about 258 watts per square metre of blanket at the start of life, at a cell temperature of over 100 degrees. | VC01 | T3 | HIGH |
| CLM-1115 | Mirrors that doubled the light only added 40 per cent to the output, because the cells ran hot and the mirrors were not flat; after thirty years of radiation the array was down to 59 per cent of where it started, and the mirrors helped even less. | VC01 | T3 | HIGH |
| CLM-1116 | Thirty years of radiation behind a hair-thin glass cover was expected to take a third of the cell's power; a cover three times thicker would give about 16 per cent more power after thirty years but weigh twenty thousand tonnes more across the satellite. The design took the thin cover and planned to anneal. | VC01 | T3 | HIGH |
| CLM-1117 | The 1977 study found the cheapest way to keep a silicon satellite at full power was to heal the radiation damage in place rather than build it bigger, that healing works best without mirrors because mirrors cannot be healed, and that a cheaper cell mattered more than a better one. That is why the reference system went to flat arrays and an annealing plan. | VC01 | T3 | HIGH |
| CLM-1118 | In 1977 five radiation-damaged cells were healed with a laser or an electron gun, getting back between a fifth and a half of what they had lost; the electron gun did better and the laser missed parts of the cells. It was a first try, and everyone said so. | VC01 | T3 | HIGH |
| CLM-1119 | Two years on, a laser could put back about half the radiation damage in a paper-thin cell in a few seconds, and an oven could put back nearly all of it in twenty minutes; but nobody could yet put a glass cover on such a cell that survived the heat, so the thing the satellite would actually carry had not been annealed. | VC01 | T3 | HIGH |
| CLM-1120 | In 1977 the gallium arsenide option rested on a 20 per cent cell nobody had made, an assumption that it would still be near 20 per cent after thirty years because it heals more easily, and on films a few thousandths of a millimetre thick, because there was not enough gallium for anything thicker. | VC01 | T3 | MED |
| CLM-1121 | Half a kilogram per square metre for the working blanket, about half of it the silicon itself; per kilowatt delivered on the ground the 1977 satellite came to six or seven kilograms, and the blanket alone to about two. | VC01 | T3 | HIGH |
| CLM-1122 | About twenty thousand postage-stamp-sized antenna-plus-diode cells, each with an off-the-shelf microwave diode, wired into tiles, then panels a metre square, then four panels side by side: a bit over four square metres in all. | VC07 | T1 | HIGH |
| CLM-1123 | A five-metre dish and a 100 kW radar-type pulsed tube a kilometre away, bounced partly off the ground on purpose to get more power onto the receiver, then deliberately blurred so the diodes would not be burnt out: about 550 watts per square metre landing on the array, from a beam that could have delivered three times that. | VC06 | T1 | HIGH |
| CLM-1124 | One panel the size of a sheet of paper turned about seven-tenths of the microwave power landing on it into DC, and did best at about three hundred watts per square metre, a little over half the highest level tested. | VC07 | T1 | HIGH |
| CLM-1125 | Four square metres of receiver turned 73 per cent of the microwave power arriving at it into 1.65 kW of DC, measured a kilometre from the transmitter; the main doubt is whether the probe antenna used to measure the arriving power sees the ground reflections the same way the receiver does. | VC07 | T1 | HIGH |
| CLM-1126 | They deliberately fried each of the four panels with ever-stronger pulses. A bare panel gave up at 672 watts out; clamping its voltage with a Zener let it take about 30 per cent more incoming power before failing, and shorting it outright about 50 per cent more, which is the best any clamp could do. | VC07 | T1 | HIGH |
| CLM-1127 | As flown, under two per cent of the microwave power fed to the dish came out of the receiver as electricity, because the beam had to be blurred to protect the diodes. The authors' arithmetic says a properly focused beam onto a receiver seven to twenty-two times larger would get a quarter to nearly half of it through; nobody has built that. | VC06 | T1 | HIGH |
| CLM-1128 | A second test used a big radar dish in Massachusetts to light up a strip of LEDs on a tower over a kilometre away, with about a kilowatt flowing during each pulse; the receiver sat well inside the dish's near field, where the beam is uneven, and turned an estimated 60 per cent of the power reaching it into DC. | VC07 | T1 | MED |
| CLM-1129 | The authors say the 1975 record still stands at twenty times their power, that the custom diodes which set it no longer exist, and that going bigger needs three things nobody has yet built for this job: many small combined transmitters instead of one big tube, a tougher diode, and the electronics to feed a rectenna into a grid. | VC07 | T2 | MED |
| CLM-1130 | A quick way to size a ground-to-ground beam: at the distance where the dish stops focusing, the cone holding half the power is about twice the dish's radius and the cone holding nine-tenths about four times; anything on the ground poking into the wider cone costs you power, and the usual radio-link clearance rules overstate how high you must build. | VC06 | T2 | HIGH |
| CLM-1131 | They ran a radio-propagation model over a map of the actual ground and found that, aimed just right, the beam plus its reflection off the ground would land nearly twice as much power on the receiver as the direct beam alone; a perfect mirror-flat ground would give almost four times, the theoretical best. | VC06 | T2 | HIGH |
| CLM-1132 | They then measured it: raising the receiver through five metres above the ground the received power jumped by about 70 per cent, close to the model's 87 per cent; the beam was as narrow as in free space side to side and a little wider up and down; and because the ground reflection varies across the receiver, they had to map the arriving power point by point rather than swing the transmitter past a fixed probe. | VC06 | T1 | HIGH |
| CLM-1133 | The exposure limits the paper cites at this frequency are 10 watts per square metre for the public, 50 for workers and 100 on military sites. Their pulsed test averaged below those everywhere except right beside the dish's feed; but had the 100 kW run continuously, the 100 W/m2 zone would have skimmed within three metres of the ground for nearly four kilometres, which is why the receiver itself has to be big enough to catch the beam, and why aircraft overhead are a separate question. | VC06 | T2 | HIGH |
| CLM-1134 | The field's own 2021 scorecard: the two records were both set in 1975 (30-35 kW across about a mile, and 54 per cent DC in to DC out at short range), and in the 45 years since, nobody listed has reported more than about a kilowatt of DC delivered, or more than about a fifth of the wall-plug power coming out as DC. | VC06 | T2 | MED |
| CLM-1135 | Modern power beaming, by the review's dating, starts in 1963 with a radar tube, a horn five and a half metres away and a single vacuum-tube rectifier: 100 watts out for about 670 in. The same year the rectenna was invented by giving every little dipole its own diode. | VC07 | T2 | MED |
| CLM-1136 | The famous 1964 helicopter hung fifteen metres up for ten hours on beamed microwaves, rectified by four and a half thousand diodes; then the Air Force lost interest and the idea went to NASA. | VC06 | T2 | MED |
| CLM-1137 | In 1987 a Canadian model plane with a four-and-a-half-metre wingspan flew for twenty minutes at 150 metres on nothing but a microwave beam from a dish below, 150 watts to the motor from 400 watts per square metre at the aircraft. | VC06 | T2 | MED |
| CLM-1138 | A 1994 Japanese test sent five kilowatts from a three-metre dish to an eleven-square-metre rectenna 42 metres away and caught about three-quarters of the beam; what came out as DC is not stated. | VC06 | T2 | MED |
| CLM-1139 | A 1995 Japanese blimp carrying a three-by-three-metre rectenna flew for four minutes at fifty metres on ten kilowatts of microwaves from two magnetrons and a dish. | VC06 | T2 | MED |
| CLM-1141 | In 2002 a metre-wide rectenna moved along an exhibition floor in Houston, tracked by a self-steering 5.8 GHz beam, converting 82 per cent of what hit it to DC in front of ten thousand people. | VC07 | T2 | MED |
| CLM-1142 | In 2015 Mitsubishi Heavy sent ten kilowatts of microwaves half a kilometre along a Kobe pier to an eight-by-eight-metre receiver, enough to light up its logo; the review gives no figure for how much came out the other end. | VC06 | T2 | MED |
| CLM-1143 | Japan's flagship 2015 ground test: a solid-state GaN array of about one and a half square metres sent 1.8 kilowatts 55 metres and 335 watts of DC came out, under a fifth of the microwave power and about one-fifteenth of the DC that went in, with the beam self-steering onto the receiver. | VC05 | T2 | MED |
| CLM-1144 | In 2019 the same Japanese array put four kilowatts per square metre onto a paperback-sized rectenna under a hovering drone ten metres up, giving about 60 watts, not enough to fly it but enough to stretch the battery. | VC06 | T2 | MED |
| CLM-1147 | The 1980 programme's experiments on bees, at strengths from the edge of a rectenna to about twice its centre, found nothing: eggs hatched, adults found their way home, a colony raised brood for a month under the edge-of-rectenna level, and foragers flew straight into fields nearly twice as strong as the beam centre to get at sugar water. | XC03 | T3 | HIGH |
| CLM-1148 | Bee eggs, grubs and pupae zapped for half an hour at up to twice the beam-centre strength grew into normal adults at the same rate as unexposed ones; the one pattern in the egg numbers, treated slightly below sham at every level including zero, the authors trace to which shelf the combs sat on afterwards. | XC03 | T3 | HIGH |
| CLM-1149 | One hive lived for four weeks, a full brood cycle, under the beam strength expected at the edge of a receiving station, and behaved like the identical hive next door with the beam off. | XC03 | T3 | MED |
| CLM-1150 | Six thousand bees took part, 2,500 of them dosed, and were let go a hundred metres from home; the dosed ones found their hive as often as the undosed. Another set was watched for three weeks afterwards in glass hives and lived as long. | XC03 | T3 | HIGH |
| CLM-1151 | Bees kept a full day at up to twice the beam-centre strength (fifty times the beam-edge level), alone or huddled, ate and lived afterwards like bees that had not been; in six-hour runs, single thermometer readings inside them and their clusters differed from the sham box's by up to about 7 degrees, in no consistent direction. | XC03 | T3 | HIGH |
| CLM-1152 | Bees flew four hundred metres to a sugar dish sitting in a microwave field nearly twice the beam-centre strength, went in without hesitating, and made twenty to thirty round trips in three hours, with no significant difference from bees whose dish had no field. | XC03 | T3 | HIGH |
| CLM-1153 | The people who ran the bee tests said so themselves: one species, in boxes whose field strength wandered by a third across the tray, with the questions of whether a warm rectenna would draw insects in winter, and birds after them, still open. | XC03 | T3 | HIGH |
| CLM-1154 | In 1978 the literature said the fence-line level was well below anything known to cause disease over the short term, that no study had come anywhere near thirty years of exposure, and that there was no data at all on what happens to a bird that flies through the beam. | XC03 | T3 | HIGH |
| CLM-1155 | The 1978 reviewers did the sum for a small bird flying four kilometres through the beam centre and concluded it would probably die of heat, on rat data and the physics of a bird the size of half a wavelength; nobody had flown a bird through a continuous beam to find out. | XC03 | T3 | MED |
| CLM-1156 | The one worrying result at the fence-line level in 1978 was thinner eggshells in hens kept twelve weeks in a metal cage whose field strength was calculated rather than measured; the reviewers kept the worry because animals living near a rectenna would also be in reflected, uneven fields. | XC03 | T3 | MED |
| CLM-1157 | The reviewers said most of the older microwave-health literature could not be trusted on how much power the animals actually got, that pulsed beams do more than steady ones at the same average, and that nobody had ever tried to assess an ecosystem. | XC03 | T3 | HIGH |
| CLM-1158 | The 1978 plan put seven hundred people in orbit at a time, on ninety-day tours of sixty-hour weeks, adding up to about 270,000 tours over thirty years, and this workshop reviewed how much radiation they would get. | XC03 | T3 | HIGH |
| CLM-1159 | A ninety-day shift in low orbit would give a worker about 20 rad, the trip up and back about 3, and ninety days at geostationary altitude 29 to 56 rad depending on where over the Earth the satellite sat, most of it from X-rays the trapped electrons make in the hull. | XC03 | T3 | MED |
| CLM-1160 | A big solar flare like August 1972 would push a spacesuited worker past the skin limit in three hours and the eye limit in two, so the geostationary base needs a storm shelter with the shielding of about 15 cm of aluminium, plus goggles and lead underwear so the shelter can be lighter; and a geomagnetic storm can make the electron belt a hundred times more intense in hours. | XC03 | T3 | MED |
| CLM-1161 | The 1978 plan assumed space workers would be allowed about ten times the radiation dose an ordinary radiation worker may take, under 1970 astronaut rules that doubled a person's natural cancer odds over twenty years at the career limit; the authors said the design, and possibly the feasibility, turned on whether those rules would be tightened. | XC03 | T3 | HIGH |
| CLM-1162 | A satellite would look like Venus all night, and for two minutes near the equinoxes its polished transmitter would flash a full-moon-bright spot 350 km wide across the ground at 150 km a minute; the ferries being built in low orbit would flash brighter still by day. Tilting or curving the panels and roughening the antenna face would cut the glints, though not the Venus-like glow. | XC03 | T3 | HIGH |
| CLM-1163 | Between the spring conference paper and the autumn final report, Boeing's figure for how bright a satellite would glow at night fell twelve-and-a-half-fold, from ten times Venus to about Venus, and the report does not say why; the factor is almost exactly what a 4-pi slip in the diffuse-reflection formula would give. | XC03 | T3 | HIGH |
| CLM-1164 | The report's worry was not that a satellite could light the ground like the sun. It was that a small bright point in a dark sky reaches an eye whose pupil is wide open. So it compared the brightness of the image on the retina with the sun's: in normal operation the transfer vehicles in low orbit reached about a tenth and the satellites far less. For an out-of-control satellite, a case the report treats as abnormal, the same comparison gives about three-tenths (the record's own arithmetic). | XC03 | T3 | MED |
| CLM-1165 | In 1978 the government said plainly what it did not know about a space power station's effects: almost nothing about long, low-level microwave exposure of people, almost nothing about birds in the beam and nothing about whole ecosystems, and no numbers yet for anything else; it gave itself two years to find out. | XC03 | T3 | HIGH |
| CLM-1166 | An early tally of ordinary industrial harm from building the system: about twenty-five million lost working days from injuries over thirty years, more than half of them in mining the materials, and a materials bill that would take a large slice of a year's national output of mercury, argon, hydrogen and oxygen. | XC03 | T3 | MED |
| CLM-1167 | For the launches the 1978 assessment could only line up the rulebook - allowed minutes of rocket exhaust gases for the public, the EPA's day and night noise levels, the blast reach of a launcher twice as explosive as a Saturn V - and note that several launches a day would probably break the noise rule. | XC03 | T3 | MED |
| CLM-1168 | In 1978 the receiving station was expected to warm its surroundings about as much as a suburb does, unless the beam went astray; one Skylab launch had already punched a 2,000 km hole in the ionosphere for hours, and only preliminary calculations existed for what daily launches would do; water dumped above 40 km was the open climate question. | XC03 | T3 | MED |
| CLM-1169 | Under the 2020 international guidelines, which keep the 1998 values, for a microwave beam at either SBSP frequency the public may be exposed to ten watts per square metre and trained workers to fifty, averaged over half an hour and over the whole body; both come from the absorbed power that raises core temperature by one degree, divided by fifty and by ten, and close in to the antenna the power-density number stops being usable at all. | VC06 | T1 | HIGH |
| CLM-1170 | In the 2020 international guidelines, besides the half-hour whole-body limit there is a six-minute limit on the hottest spot on the body, 40 watts per square metre for the public and 200 for workers at these frequencies, and a rule for bursts shorter than six minutes that lets a single brief pulse carry at most about 720 joules per square metre for the public. | VC06 | T1 | HIGH |
| CLM-1171 | In the 2020 international guidelines, the lower public limit exists because the public includes children, the sick and the unaware, and anyone pregnant counts as public even at work; you may show compliance by either the external field number or the absorbed-power number, and need not show both; and ICNIRP admits that its public limits between 1 and 4 GHz, which include 10 W/m2 at 2.45 GHz, can over-expose a small child by up to 40 per cent, and has chosen not to lower them. | VC06 | T1 | HIGH |
| CLM-1172 | A 2025 UK government study tried two places for the receiving station, Aberdeen and southern England near London. Southern England came out better, because the grid there can take the power almost all the time while Aberdeen's connections would lose a quarter of it. | VC07, XC02 | T4 | MED |
| CLM-1173 | A 1980 European survey for offshore receiving stations looked only at the North Sea and the Channel, left the Atlantic and Mediterranean for later, and listed distance to the grid among its siting factors, though it chose the areas on its offshore factors alone. Because the beam's footprint stretches north to south at those latitudes, coasts running east to west fitted badly. | VC07, XC02 | T3 | MED |
| CLM-1175 | The design would control its orientation without fuel. Small mirror panels near its front carry a coating whose reflection can be changed electrically. Changing how much sunlight each panel reflects changes the push of sunlight on it, which can damp the satellite's wobble and control it about all three axes. A Japanese satellite, IKAROS, used the same kind of coating. | VC04 | T2 | MED |
| CLM-1176 | Each transmitting element on the satellite is a small cluster of three short rod antennas standing a quarter of a wavelength apart, all pointing along the long axis of the helix. They pass through a flat layer at their middle, which feeds them and acts as their ground plane. | VC05 | T3 | MED |
| CLM-1177 | The flat layers that carry the antennas must be stacked at least a quarter of a wavelength apart, but not so far apart that neighbouring antennas are more than about six-tenths of a wavelength away, or the beam grows unwanted side beams. The layers are very thin, less than a twentieth of the gap between them. | VC04, VC05 | T3 | MED |
| CLM-1178 | The antenna is one twisted surface, like a ribbon turned half a turn from top to bottom. Looking down its axis you see a complete circle; from one side it looks like an hourglass, and it presents the same area to the Earth whichever way it faces. | VC04, VC05 | T3 | MED |
| CLM-1180 | The most powerful version adds curved mirrors at both ends of the satellite. Each end's pair of mirrors squeezes the sunlight to twice its normal strength, and because the light comes in from both ends, each layer gets four times normal sunlight in total. | VC04 | T2 | MED |
| CLM-1181 | A student study built with the designer's input describes a small version, about 260 metres across and as tall as it is wide, for 24 megawatts. The surface is upright at the centre and leans over towards the rim, to about a third of a right angle. | VC04 | T5 | MED |
| CLM-1182 | In this study the huge twisted surface is tiled with small six-sided panels, each about 0.6 to 1.1 metres across. Each panel is a little staircase of thin strips a few centimetres apart, with the antennas standing between the steps and solar cells on both faces of each strip, except near the centre where the strips would shade each other. | VC04, VC05 | T5 | MED |
| CLM-1183 | ESA's 2026 report counts about 960 catalogued objects in geostationary orbit at the end of 2025, about 800 of them satellites, but nearly 9,700 objects pass through the protected zone around it at some point in their orbits. A separate chart counts about 1,870 satellites near geostationary orbit in 2025, more than half of them drifting. | VC12, XC04 | T3 | HIGH |
| CLM-1185 | The top-power version uses two pairs of curved mirrors, one pair at each end. Each pair doubles the sunlight and turns it sideways into the stack, so the stack gets four times normal sunlight in total. The patent gives the best mirror tilt for each pair's own concentration. It works this out for a pair that concentrates in two directions: about 16.5 degrees for a doubling, and about 11 degrees for a single pair that quadruples the light. The four-times system itself is built from a simpler kind of pair that concentrates in one direction only, and for that kind the patent gives mirrors tilted at 22.5 degrees. | VC04 | T3 | MED |
| CLM-1186 | The patent describes an existing kind of solar collector whose layers step up like a staircase, with risers that can be panels that shed heat; it does not say its own helical design has such risers. In the helical design the rows are typically 14 millimetres apart, and the whole thing may be hundreds to thousands of metres across and tall, so it has many thousands of rows. | VC04, VC05 | T3 | MED |
| CLM-1187 | The middle of the collector, a tenth of its area seen end-on, has no solar cells, so the mirrors have a hole in the middle rather than reflecting light that would be wasted. The hole's radius is about a third of the mirror's radius. | VC04 | T3 | MED |
| CLM-1188 | Over the past ten years, almost every satellite retiring from the geostationary belt has tried to move itself out of the way as the debris rules ask, but only about seven to nine in ten have managed it, and the report notes two bad years, 2015 and 2022. | VC12, XC04 | T3 | MED |
| CLM-1189 | A 1990 NASA study of powering a Moon base from orbit put the satellites in circles over the Moon's equator, beaming down to a flat receiver at an equatorial base that can see a wide cone of sky. The higher the orbit, the fewer satellites it takes to keep one always in view: 30 at 90 km, 4 at about 2,500 km, 3 at about 10,600 km. | VC04, VC06 | T3 | HIGH |
| CLM-1190 | The study's reference design uses four satellites about 2,500 km above the Moon, each about the size of a space station (148 by 58 m): a 58 m square microwave antenna between two solar wings. Between them they beam a steady 1 MW to the base at 100 GHz, with batteries on board for when a satellite is in the Moon's shadow. | VC04, VC05 | T3 | HIGH |
| CLM-1191 | The study sized its transmitting and receiving antennas with a standard beam formula, assumed about half the transmitted power would be caught on the way down, and found that above 35 GHz the antennas are small enough that they stop mattering much to the total mass, and that going beyond 100 GHz gains little. | VC05, VC06, VC07 | T3 | MED |
| CLM-1192 | With 1990 technology the orbiting system came out heavier per kilowatt than solar panels on the ground with enough storage for the lunar night. With the technology the study projected, the four-satellite reference came to about 330 kg per kilowatt, below the roughly 500 projected for surface solar but far above the roughly 20 for a large nuclear plant. | VC04 | T3 | HIGH |
| CLM-1193 | A 1979 study for NASA drew the pilot transmitter's beam about three-quarters of a degree wide, a few hundred kilometres across by the time it reaches the satellites, and argued that with 100 satellites spread along a sixth of the orbit only one would sit in each pilot beam; the others would see a site's pilot only through its much weaker side lobes. | VC05, VC06 | T3 | MED |
| CLM-1194 | The company's first planned project is sized at 200 MW to the grid from a 732-tonne satellite, running nine-tenths of the time over a 20-year life; a later project is 40 times bigger. | VC04, XC02 | T4 | MED |
| CLM-1195 | The design builds one thin, nearly kilometre-wide disc out of many metre-sized flat satellites, each with solar cells on one side and radio transmitters on the other; the first project's disc is 967 m across. | VC04, VC05 | T4 | MED |
| CLM-1196 | A separate, very light mirror flies beside each array and turns slowly, once a year, so the solar cells always see the Sun; for the first project it is about twice the area of the array, but the design does not count it as concentrating the light. | VC04 | T4 | MED |
| CLM-1197 | The company beams at 10 GHz and claims its beam loses nothing in space on the way down, where the other designs in its own table lose between a sixth and a half. | VC05, VC06, VC07 | T4 | MED |
| CLM-1198 | The first project's receiving site is a circle 2 km across, with two hours of batteries on the ground. | VC07 | T4 | MED |
| CLM-1199 | On its long, looping 12-hour orbit each array hangs over one region for about 11 and a half hours, then on the next loop serves a region about halfway round the world; the company plans 16 of them. | VC06, VC10 | T4 | MED |
| CLM-1200 | A 2025 UK study says Virtus Solis counts the power its receiving site catches in a way the other designs do not: on their common method, a receiver that collects only the central spot of the beam can catch at most about 84 per cent of it. | VC06, VC07 | T4 | MED |
| CLM-1201 | Caltech's design has no single large structure. Many separate square craft, each 60 metres across, fly side by side in geostationary orbit and act together as one antenna 1.6 kilometres wide. Each craft is launched rolled up into a drum about 2 metres wide and 1.5 metres tall, and unrolls in orbit. | VC04, VC05 | T2 | MED |
| CLM-1203 | Caltech's receiving station on the ground is a circle about 1.6 kilometres across, just large enough to catch the whole central spot of the beam. Batteries keep its output steady through the short eclipse seasons and the dips while the craft turn. | VC06, VC07 | T2 | MED |
| CLM-1204 | A 1981 US government study worked out what happens when an airliner flies through the beam. Its wings would reflect some of the beam, mostly away from the cabin. It judged the passengers' exposure insignificant, because the windows are small and the plane is in the beam for under a minute. | VC06, XC01 | T3 | MED |
| CLM-1205 | A 1981 US study worked out what a satellite in low orbit feels when it flies through the beam. For a craft like LANDSAT, the strongest part lasts about a second and the whole crossing about 13 seconds. In tests, one of its cameras failed completely when enough of the beam's power shone into it. The study suggested such satellites could pause commands during a crossing for now, and be redesigned later. | VC06, XC01 | T3 | MED |
| CLM-1207 | The 1980 paper that estimated how often a satellite would meet the beam used a simple picture: the beam turns with the Earth once a day, so a given satellite gets about two chances a day to cross it, and whether it does depends on where in its orbit it happens to be. The paper does not say how wide it took the beam to be, or show its sums. | VC06, XC01 | T3 | MED |
| CLM-1208 | A start-up, TerraSpark, says Luxembourg is paying it, through a European Space Agency contract, to build a test that sends power without wires over 100 m on the ground, plus research on solar cells and receiving antennas for power satellites in low orbit. Only the company has said so. | VC06, XC05 | T6 | MED |
| CLM-1209 | TerraSpark says it has sent power without wires across half a metre, is testing over a longer distance in the lab now, and plans a test in space in 2027 paid for privately. Only the company has said so. | VC06 | T6 | MED |
| CLM-1210 | Britain's grid runs at 50 Hz, normally kept between 49.5 and 50.5 Hz. A power station connected to it, which would include a rectenna, must keep running between 49 and 51 Hz without limit, and for set minimum times further out, down to 47 Hz and up to 52 Hz. | VC08, VC09 | T1 | HIGH |
| CLM-1211 | Britain's main transmission grid runs at 400 kV and 275 kV, and parts of the 132 kV network in Scotland. On the 400 kV network the voltage normally stays within 5 per cent of its nominal value and never beyond 10 per cent outside abnormal conditions. The rules read do not say how the connection voltage for a given plant is chosen. | VC08 | T1 | HIGH |
| CLM-1212 | A space solar start-up says it has signed a 20-year deal to sell power from orbit to a data-centre company: 100 MW at first, perhaps 250 MW later, received in Illinois. Only the two companies have said so, and no price or start date is given. | VC09, XC02 | T6 | MED |
| CLM-1213 | The first buyer wants the power for underwater computer centres for AI. The release pitches power from orbit as a fix for AI's power and cooling limits. | VC09 | T6 | MED |
| CLM-1214 | The company says its beam will be on 99.9 per cent of the time, and that a 2 million dollar development agreement with a US government energy agency (ARPA-E) supports its work. It plans a public power-beaming demonstration in March 2027 and says it expects record efficiency. None of this is independently confirmed. | VC05, VC06, VC12, XC02 | T6 | LOW |
| CLM-1215 | The deal was announced on the day of a space solar session in Washington, D.C., where the company says its chief executive will speak. | VC09 | T6 | MED |
| CLM-1216 | The company says more customers are lined up. It names none and gives no numbers. | VC09, XC02 | T6 | LOW |
| CLM-1217 | In a 2023 talk, the designer said four satellites in a stretched 8-hour orbit could keep three receiving sites supplied day and night all year. The slide gives the figures but not how they were worked out. | VC04 | T5 | LOW |
| CLM-1218 | SPS-ALPHA's design catches sunlight with a few thousand units of large, thin plastic-film mirrors. The mirrors are grouped into several hundred assemblies, and each assembly points on its own, like the mirrors around a solar tower plant, but the frame they sit on stays still, so the design needs no big moving joint. | VC04 | T3 | MED |
| CLM-1219 | SPS-ALPHA's mirrors concentrate sunlight about three times on the array. The report estimates that five times would save almost 15,000 tons, if the array could stand the extra heat. | VC04 | T3 | LOW |
| CLM-1220 | The receiving site sends a guide signal up to the satellite, and the satellite's many small transmitters use it to line up their beams on that site. The design uses 2.45 GHz microwaves. | VC05 | T3 | MED |
| CLM-1221 | IRENA now prices solar power with batteries built to a 95% reliability level, which its summary does not define. At the best sites, it puts this below 8.5 US cents per kilowatt hour in 2025, down from over 10 cents in 2020. | XC02 | T3 | MED |
| CLM-1222 | The fourth paper the 1978 design cites for its beam limit also calls the limit a theory that had not been tested. The one experiment it reports, at Arecibo in 1977, heated the upper atmosphere less strongly than the satellite would and found nothing, so it did not test the limit. | VC06 | T3 | HIGH |
| CLM-1223 | In 2019 China's state news agency said the country's main space-technology academy planned a megawatt-scale solar power station in space by 2035, weighing about 200 tonnes, and was spending about 28 million US dollars on a ground test site in Chongqing. | VC10, XC04 | T5 | MED |
| CLM-1224 | A UK space solar start-up said in 2024 that it had a deal to supply an Icelandic utility with 30 MW from orbit by 2030. | VC09, XC02 | T6 | MED |
| CLM-1225 | A US start-up said in late 2025 that it had beamed power from a plane to the ground, and planned an orbital test in 2028 and its first megawatt from space in 2030. | VC05, VC06, XC02 | T6 | MED |
| CLM-1226 | In April 2026 Meta said it had reserved up to 1 GW of future space solar power from Overview Energy, with a test in 2028 and power possibly from 2030. | VC09, XC02 | T6 | MED |
| CLM-1227 | China's state broadcaster said in 2022 that China planned a 10 kW orbital test in 2028, 10 MW by 2035 and a 2 GW commercial plant by 2050. | VC05, VC06, XC04 | T5 | MED |
| CLM-1228 | A US start-up said its first power-beaming satellite would launch in October 2026 and try to send power to another spacecraft. | VC05, VC06 | T6 | MED |
| CLM-1229 | A lunar lander company said in late 2025 that it would carry a power-beaming receiver to the Moon for a start-up planning orbital power missions from 2028. | VC06, VC07 | T6 | MED |
| CLM-1230 | US regulators approved a test satellite with an 18-metre mirror to reflect sunlight to the ground at night, despite objections from astronomers. | XC01, XC03 | T5 | MED |
| CLM-1231 | In 2009 a California utility agreed to buy 200 MW from a space solar company by 2016. No held source records what became of it. | VC09, XC02 | T5 | MED |
| CLM-1232 | In 1978 a NASA contractor designed a satellite that would turn sunlight into an infrared laser beam and send it, by way of a mirror satellite high above the equator, to a ground station about 30 m across. The ground station would use the beam as heat to run turbines. On paper, about 5 to 6 per cent of the sunlight collected in space would reach the grid as electricity. | VC05, VC06, VC07 | T3 | MED |
| CLM-1233 | The design's beam would be very intense at the receiver, about two thousand times stronger than sunlight, so the site would need a fenced zone a few hundred metres across. At the fence, the study says, the infrared light would be far below the eye-safety limit of the day. A passing jet would warm slightly, but a slow light aircraft might be harmed. | VC06, VC07, XC01 | T3 | MED |
| CLM-1234 | A second NASA-funded study in 1980 imagined the standard power satellite with its microwave transmitters swapped for about twenty very large infrared lasers. On paper, about one-seventh of the electricity made on the satellite would reach the grid, a bit more on mountain sites. The receivers would again turn the beam into heat. | VC05, VC06, VC07 | T3 | MED |
| CLM-1235 | Studies from around 1980 used an infrared safety limit of about one-tenth of strong sunlight for long, whole-body exposure, and ten times that for brief exposure of small areas. Meeting it meant fencing off a zone a few hundred metres across around each receiver and keeping aircraft out of the beam. | VC06, XC01 | T3 | MED |
| CLM-1236 | Clouds block a laser beam far more than a microwave beam. A 1980 NASA-funded study found that over most of the United States a single laser receiver would be clouded out too often to be a dependable power station, so each beam would need two or three receivers hundreds of kilometres apart and would have to switch between them, sometimes every few hours. | VC06 | T3 | MED |
| CLM-1237 | The colour of the laser light decides how much of it gets through the air. The calculations found almost no loss near 2 micrometres on a clear day, but the 10.6 micrometre carbon dioxide laser of the earlier designs would lose more than half its beam at sea level. | VC06 | T3 | MED |
| CLM-1238 | In 1978 the US energy department asked whether lasers could replace the microwave beam. Its review said the lasers of the day were not good enough, mainly because they wasted too much electricity, but that they might become good enough in time. | VC05, VC06 | T3 | MED |
| CLM-1239 | In 1993 US government laboratories and a satellite company planned to shine a powerful red laser from a New Mexico telescope at mirrors left on the Moon and then at a communications satellite, to see whether the satellite's solar panels would register it. The paper shows that without correcting for air turbulence almost all of the beam would miss a satellite that far away. | VC06 | T3 | MED |
| CLM-1240 | In 1999 a US national laboratory sent infrared light from a bank of laser diodes across a lab room onto ordinary solar cells and got a few watts out, enough to turn a small motor. The beam was patchy and the run was cut short, so less than one per cent of the electricity put in came out at the far end. | VC05, VC06, VC07 | T3 | LOW |
| CLM-1241 | TerraSpark's boss argues that space solar power cannot be paid for as one giant project. It should be built in small steps that each prove one thing, so that risky early money can give way, step by step, to the cheaper money that pays for power stations. The article gives no figures. | XC02, XC05 | T6 | MED |
| CLM-1242 | TerraSpark says it will first use wireless power on the ground, where cables are hard to lay, and move parts of the system into space later. The article suggests Luxembourg could become a financial centre for such projects. It gives no dates. | VC07, XC01, XC05 | T6 | MED |
| CLM-1243 | The company says it is lining up partners in Japan, the US, Saudi Arabia and Canada, and working with the European Space Agency. It pitches beamed power as something Britain could offer its allies, including for defence and polar sites. It says the ground receivers would be cheap enough to finance even in poorer countries. None of this is backed by named deals or figures in the post. | XC01, XC02, XC04, XC05 | T6 | MED |
| CLM-1244 | TerraSpark posted a lab video of power sent without wires across half a metre, with words of praise from a former British energy and defence minister. The post gives no numbers on how much power was sent or how efficiently. | XC01, XC05 | T6 | MED |
| CLM-1245 | In 2016 a senior Chinese military official told state media that China planned to use the space between the Earth and the Moon for solar power after its space station was built, but that a full-scale plant, over 10,000 tonnes, was beyond current technology. | VC10, XC04 | T5 | MED |
| CLM-1246 | In 2019 a Chinese state science paper said China had started building a test base in Chongqing, planned high-altitude solar stations by 2025, a megawatt-scale test station in space from 2030 and the ability to build a gigawatt commercial plant by 2050. | VC10, XC04 | T5 | MED |
| CLM-1247 | Japan's 2023 national space plan lists space solar power research, led by its science and industry ministries, and aims at eventual practical use without giving a date, size or budget. | XC01, XC02 | T3 | HIGH |
| CLM-1248 | By December 2025 Japan's space roadmap said hardware for a large-structure test had been handed over for a supply-ship flight, and a satellite to beam power from low orbit to the ground had been built. | VC04, VC05, VC06 | T3 | HIGH |
| CLM-1249 | Japan's December 2025 space roadmap plans to launch a solar power demonstration satellite, OHISAMA, on a private Kairos rocket in the year from April 2026, to beam power from low orbit to the ground. | VC05, VC06, VC10 | T3 | HIGH |
| CLM-1250 | In a 2015 ground test in Japan, a 1.8 kW microwave beam sent over 55 m delivered about a third of a kilowatt when the steering corrected a deliberate panel misalignment, and about 90 W, roughly a quarter of that, when it did not. | VC05, VC06, VC07 | T5 | MED |
| CLM-1260 | In 2009-2011 California's regulators took a contract to buy power from a space solar company through each formal step: the energy commission accepted a 200 MW space solar receiving station as a renewable source in principle, and the utility regulator signed off on the contract's emissions terms. None of these papers shows the satellite or the station being built. | VC09, XC01 | T3 | HIGH |
| CLM-1261 | In 2009 California's largest utility signed a deal to buy up to 200 megawatts of power from a space solar company for 15 years, starting in June 2016, from a receiving station in central California. It agreed to pay more than the usual benchmark price, and the details were kept confidential. | VC09, XC01, XC02 | T3 | HIGH |
| CLM-1263 | In 2003 ESA planned a two-year set of paper studies to help its member countries decide whether space solar power was worth pursuing. The plan aimed to compare it fairly with solar power on the ground and to pick a few demonstration missions to study, not to fund hardware. | XC01, XC02 | T3 | HIGH |
| CLM-1264 | The plan had three steps. First, check whether space solar makes sense against ground solar, what the law allows, and whether it could power Mars missions. Second, compare system designs and pick up to three. Third, study two or three small demonstration missions in enough detail for ESA to decide whether to go ahead. | VC09, XC01, XC02 | T3 | HIGH |
| CLM-1265 | ESA planned to finish the whole set of studies in under two years, roughly 2003 to 2005, with the three steps taking about six, six and eight months. | XC02 | T3 | HIGH |
| CLM-1266 | ESA set up a small expert advisory group and its in-house futures team to steer the studies. It also linked the work to a wider European research network bid that brought together energy, combustion and space groups. | XC05 | T3 | HIGH |
| CLM-1267 | ESA also wanted to know whether beaming solar power from a satellite could power Mars and Moon bases or distant probes, because Europe had no nuclear space power sources of its own and building them would be costly. | VC06, XC04 | T3 | HIGH |
| CLM-1268 | In 2003 ESA's own rough internal sums suggested space solar and comparable ground solar would cost about the same, to within a factor of ten, and that a space solar plant would return more energy than it took to build. ESA treated both as unproven and planned studies to check them. | XC02, XC03 | T3 | MED |
| CLM-1269 | When the UK's space solar coalition launched in March 2022, its co-chair told a newspaper that a British system could supply about a third of the country's future electricity by the mid-2040s. He said the effort was looking for 75 million pounds over two years at first, and 300 million pounds over five. | XC02, XC05 | T5 | MED |
| CLM-1272 | In 2000 NASA sketched a path from small demonstrations around 2006 to a first full-size power satellite prototype between 2025 and 2035, and very large systems after 2050. None of it was funded, and none of the dated steps has happened in a held source. | VC10, XC01 | T5 | HIGH |
| CLM-1274 | NASA said its programme had built a test solar panel that it expected to lead to arrays more than three times lighter per watt than the best of the day, kept its power beams to about a tenth of midday sunlight for safety, and found that the very high voltages assumed in 1979 would not work in space. | VC01, VC04, VC05 | T5 | MED |
| CLM-1275 | A small Canadian group founded in 2025 campaigns for space solar power. It wants tax breaks for companies working on it, a promise that the government will buy the power, and a law it has drafted itself. | XC02 | T5 | MED |
| CLM-1276 | In 2021 Caltech said a private donor and his wife had given it more than 100 million US dollars since 2013 to set up its space solar power project. The donors would not make money from it. The first test in space was planned for early 2023. | XC02 | T5 | MED |
| CLM-1277 | A 2026 expert commentary says the 1970s studies behind the 230 watt beam limit looked only at calm conditions over mid-latitudes. In the author's view, the single limit should be replaced by one that changes with the state of the upper atmosphere. | VC06 | T2 | MED |
| CLM-1278 | A 2026 expert commentary points out that the upper atmosphere would scatter a small share of a power beam, as it does a research radar's signal, but far more strongly, so it needs checking against Wi-Fi limits. Rocket tests that made the beam produce other radio signals measured them only close by, so how far those signals could travel is unknown. | VC06, XC01 | T2 | MED |
| CLM-1279 | A 2026 expert commentary suggests that power-satellite and grid operators at mid-latitudes might get about an hour's notice of space storms that would weaken the beam, enough to adjust, though not ideal. | VC06 | T2 | MED |
| CLM-1280 | In July 2023 Europe's space agency asked researchers for ideas on the safety questions around beaming power from space: effects on people, wildlife, the atmosphere, aircraft and the carbon cost of launches. Ideas were due within four weeks, and the best would compete for jointly funded research projects. | VC01, XC02 | T6 | HIGH |
| CLM-1283 | In 1981 the US Congress's technology office worked out that keeping the edge of a receiving site to the Soviet limit would make each site about ten times bigger, close to 1,700 square kilometres. That limit is ten times stricter than the American design boundary. | VC07, XC01, XC03 | T3 | MED |
| CLM-1284 | In 1981 the US Congress's technology office said there was not enough evidence to judge the health risk of living near a power-satellite receiver for years. It expected little harm outside the site, could not rule out effects inside it, and said this research should come first. | VC06, XC01, XC03 | T3 | MED |
| CLM-1285 | In 1981 the Soviet limit for workers was a thousand times stricter than the US one, and the US had no public limit at all. Congress's technology office expected US limits to tighten and said the design should be checked against that. | VC06, XC01 | T3 | MED |
| CLM-1286 | The 1981 congressional assessment listed who would be exposed to the beam and how strongly. Levels ran from a ten-thousandth of a milliwatt per square centimetre for the public to about 2 watts for workers at the satellite's antenna, and it said no one could yet say what was safe for workers. | VC06, VC07, XC01 | T3 | MED |
| CLM-1287 | In 1978 a draft plan for the US satellite power programme proposed that every lab test rats the same way, at fixed microwave levels from far below to just above the beam-centre level of the later reference design, for at least four hours a day, and later for 23 hours a day. | VC07, XC03 | T3 | MED |
| CLM-1288 | The 1978 draft plan said long-term low-level studies would decide whether the satellite was safe for the public, but that in the two to three years available most effort would go to checking earlier alarming reports, with three-fifths of the money on health. | VC07, XC03 | T3 | MED |
| CLM-1289 | The 1978 plan aimed to find, by stepping the dose up or down, the lowest microwave level that changed anything in mice, rabbits, birds and plants, and to use the rabbit result to inform human safety standards. | VC07, XC03 | T3 | MED |
| CLM-1290 | A 1963 US aviation agency study set the safe level for an aircraft flying through a radar or radio beam at the then human exposure limit, 10 milliwatts per square centimetre, and ten times lower for aircraft carrying explosive devices. | VC06, XC01 | T3 | MED |
| CLM-1291 | The 1963 study assumed an aircraft crosses a radar beam in a few seconds at most, too short to wear out its radio parts, though a switched-off radar set could still be damaged by a strong pulse. | VC06, XC01 | T3 | MED |
| CLM-1292 | In 1966 Canadian researchers found that caged birds under a pulsed radar-band beam at roughly the strength proposed for a power beam's centre reacted within seconds, but only when the beam came from above. | VC07, XC03 | T1 | LOW |
| CLM-1293 | A year later the same laboratory found chickens under a pulsed beam at a strength about twice the proposed beam centre went lame on one side or fled within seconds, and barely reacted when the beam came from beneath. | VC07, XC03 | T1 | LOW |
| CLM-1294 | The fullest of the four papers: caged birds under a pulsed beam above them reacted within seconds at about twice the proposed beam-centre strength and more slowly at lower strengths, pigeons stayed drowsy for half an hour after two minutes, and birds lit from below barely noticed. | VC07, XC03 | T1 | LOW |
| CLM-1295 | Wiring a chicken's muscles showed the beam made one side tense and the other go slack within moments, and the bird was back to normal seconds after it was switched off. | VC07, XC03 | T5 | LOW |
| CLM-1296 | A 1977 paper suggested that a solar power satellite's beam, if moved to a frequency that water vapour absorbs, could heat water vapour, cloud and rain to change the weather. It took the beam at the ground to be 100 to 1000 W/m2, which is roughly half to four times the later 230 W/m2 design centre. | VC06, XC03 | T1 | MED |
| CLM-1297 | In the 1970s the East set microwave limits about a thousand times lower than the US. Against the later 230 W/m2 beam centre, the Soviet public limit is 23,000 times lower and the Polish general-population limit 230 to 2,300 times lower. Poland banned any human exposure above 100 W/m2. | XC01 | T3 | MED |
| CLM-1298 | In 1982 the US limit at SBSP frequencies was halved, from 10 to 5 mW/cm2, and for the first time it was meant to cover the general public as well as workers. The 1978 beam centre of 230 W/m2 is 4.6 times this limit. | XC01 | T1 | HIGH |
| CLM-1299 | The 1982 US limit was set by taking the lowest dose at which animals' trained behaviour was disrupted, about 4 W/kg, and dividing by ten. The standard admits the factor of ten was a safety margin without a quantitative justification, and one biologist dissented on that point. | VC06, XC01 | T1 | HIGH |
| CLM-1300 | Pregnant rats kept almost all day in a microwave field at a fence-line level (5 W/m2, about a fiftieth of the 1978 beam centre) had more pups die in the first week and pups that developed a day late. The authors called for replication. | VC06, XC03 | T3 | LOW |
| CLM-1301 | The pregnant rats absorbed about 0.4 W per kilogram, the same as the whole-body figure the 1982 US standard later used as its limit, yet the litters still showed the early deaths and delays reported in the companion paper. | VC06, XC03 | T3 | LOW |
| CLM-1302 | Months of night-time exposure at about a fifth of the 1978 beam centre made rats eat and drink less, but changed nothing else that was measured. The authors argue that absorbed dose, not frequency, explains the result. | VC06, XC03 | T3 | LOW |
| CLM-1303 | Hamsters kept in a field from under half to slightly above the 1978 beam-centre level for most of each day showed small brain-cell changes under the microscope in some animals. The author thought the changes would reverse but did not test that. | VC06, XC03 | T3 | LOW |
| CLM-1304 | Rabbits kept for six months in a field of about 70-100 W/m2, below the 1978 beam centre, showed no tissue damage and no clear blood changes. Their immune cells responded somewhat less to one stimulant in the test tube a month later. Four animals per group is too few to settle it. | VC06, XC03 | T1 | MED |
| CLM-1305 | Six months nearly round the clock in a field of about 100 W/m2 at the head did not cause cataracts or other eye changes in four rabbits. Acute cataracts in rabbits in the cited earlier work needed more than 100 mW/cm2. | VC06, XC03 | T1 | MED |
| CLM-1307 | An "energy return" figure for solar power can be stated in two ways, counting the electricity itself or counting the fuel a power station would have burned to make it, and in the worked example of the 2016 international guidelines the second is about three times larger. Any SBSP figure set beside a ground solar figure has to use the same way of counting. | XC02, XC03 | T3 | HIGH |
| CLM-1308 | "Energy payback time" and "energy return" are two views of one calculation and can be converted only when the lifetime and counting method are known. Neither says how much of the sun's or the fuel's energy a system uses up; that is a separate measure. | XC02, XC03 | T3 | HIGH |
| CLM-1309 | A fair energy-return comparison of SBSP with ground solar counts the same things for both: the energy to build, run and scrap each, including the supply chain, measured at the same point, power into the grid. Storage and round-the-clock supply are not credited to any one technology under these 2016 rules for solar power. | XC02 | T3 | HIGH |
| CLM-1310 | The 2016 guidelines recommend default lifetime, wear-out and performance numbers for a ground solar energy-return study, and list 16 facts every study must report. An SBSP figure can be checked against the same list to see whether it is comparable. | XC02, XC03 | T3 | HIGH |
| CLM-1311 | The 1979 design sends a sample of the reference back up each cable and adjusts until the far end matches the source. That makes cable length stop mattering. What still matters is any difference between the trip out and the trip back, and small fixed offsets in each box. These pile up from the centre to the antenna elements. | VC05 | T3 | MED |
| CLM-1312 | In 1979 the contractor simulated the whole reference-distribution tree. Small, random timing errors were added at each branching level, and the simulation measured how much beam power was lost. To keep 96% of the ideal beam, the errors could add up to about 12 degrees, or about 6 degrees at each of four levels. | VC05 | T3 | MED |
| CLM-1313 | An error near the antenna elements is different at each element. It averages out in pointing but scatters power. An error near the centre is shared by a whole block of the array. It tilts that block and pushes the beam off target. | VC05 | T3 | MED |
| CLM-1314 | The international radio-astronomy standard says how weak a stray signal must be before it spoils a sensitive observation. In the radio-astronomy bands just above the 2.45 GHz and near the 5.8 GHz power-beam frequencies, that level is about 10^-24.7 and 10^-24.1 watts per square metre per hertz. Longer observations and satellites in geostationary orbit make it stricter still. | VC06, XC01 | T2 | HIGH |
| CLM-1315 | The 1975 estimate of the satellite's radio noise, taken at its own frequency, is about a hundred million times above today's threshold for spoiling radio astronomy. The noise in the astronomy band itself would be lower, by an amount nobody has yet read from the 1975 study. | VC06, XC01 | T3 | MED |
| CLM-1316 | The world makes about 900 tonnes of raw gallium a year, almost all of it in China, and could make about 1,700 tonnes. Gallium is one ingredient of the high-efficiency solar cells some space designs assume. | VC01, XC05 | T1 | HIGH |
| CLM-1317 | There is no reliable world total for germanium output, the material many space solar cells are built on, and its price roughly doubled in 2025. | VC01, XC05 | T1 | HIGH |
| CLM-1318 | The world refines about 1,100 tonnes of indium a year, most of it in China. | VC01, XC05 | T1 | HIGH |
| CLM-1319 | The two frequencies power satellites would use sit in bands set aside for industrial and medical equipment, where radio services already there must put up with interference. The treaty's limits on how strong a satellite's signal may be at the ground do not cover either band. | XC01 | T1 | HIGH |
| CLM-1320 | The radio regulator's 2026 report on beamed power now has a section on power satellites, built around a UK design, and repeats that UK and European studies found it workable. It says nothing about effects on the upper atmosphere. | VC06, XC01 | T1 | MED |
| CLM-1321 | The 2012 design study for SPS-ALPHA put the weight of its 2 gigawatt satellite at about 35,000 tonnes, about half of it in the transmitter. | VC04 | T3 | MED |
| CLM-1322 | Around 1970 an author at Atomics International (North American Rockwell) reviewed Soviet research and asked why Soviet limits were up to a thousand times stricter. He found the Soviets took non-heating effects seriously, reported long-term symptoms in workers, and turned that concern into lower limits through shorter lines of communication than the US did. | VC06, XC01 | T5 | LOW |
| CLM-1323 | By 1970 most western countries used a limit of 10 milliwatts per square centimetre, first chosen in 1957 for lack of better data. The Soviet Union and Poland allowed a thousand times less, because they accepted evidence of effects that do not come from heating. | VC06, XC01 | T2 | MED |
| CLM-1324 | In 1981 two US officials said America still had no enforced microwave exposure standard and that its proposed limit was among the most permissive in the world. They reported the view of some that the gap with the Soviet Union came from different evidence and different readings of it, and said closer medical checks on Soviet workers may explain why Soviet studies report many mild, reversible symptoms at very low levels. | VC06, XC01 | T5 | LOW |
| CLM-1325 | In 1979 American and British radiation officials worked out that the then-standard limit of 10 milliwatts per square centimetre was safe at 2.45 GHz (the frequency planned for power satellites; our context, not on the page), about nine times below the level that warms the body by 1 C (our arithmetic). They said it was too loose at much lower frequencies, where the body absorbs more. | VC06, VC07, XC01 | T2 | MED |
| CLM-1326 | A 1980s US federal health review of animal studies put the onset of harm at about 2 watts absorbed per kilogram of body, mostly from heating. Below about a tenth of that it found few effects and none it judged harmful, though a cancer-promotion result at 2-3 W/kg was unconfirmed. | VC06, VC07, XC03 | T3 | MED |
| CLM-1327 | In 1972 the experimental evidence put the onset of microwave cataracts at about 10 times the then US limit, for acute exposures, and found the 1-3 GHz band the most effective. Nobody had tested years of low-level exposure. | VC06, XC03 | T2 | MED |
| CLM-1328 | Studies of radar and microwave workers up to 1972 found small lens changes but no clear cases of cataract below about ten times the US limit. The reviewers saw no harm at the limit but said nobody had shown that years of low-level exposure were harmless. | VC06, XC01, XC03 | T2 | MED |
| CLM-1329 | A 1972 US government-funded report found that cataracts in animals needed about ten times the worker limit for an hour or more, and that the range between the limit and that level had never been properly studied in people. | VC06, XC03 | T3 | MED |
| CLM-1330 | A 1964 Polish study found that workers exposed for longer to weak radio and microwave fields reported more headaches, sleep problems and similar complaints, and argued that safety limits based only on heating were too lax. | VC06, VC07, XC01 | T2 | LOW |
| CLM-1332 | By the mid-1980s Western limits were set from the energy the body absorbs, with a tenfold margin below the level that upset animal behaviour. The Soviet limit for a working day stayed far lower. | VC06, XC01 | T2 | MED |
| CLM-1333 | By 1986 one early long-term rat study had hinted at more tumours at the level US rules called safe, but it was unconfirmed. Eastern European reports of nerve symptoms had not been confirmed by careful studies, and experts said there was no theory to predict any non-heating effects. | VC06, VC07, XC01 | T2 | LOW |
| CLM-1334 | In 1978 the US environment agency calculated that the American safety limit of the time could, at some radio frequencies, heat parts of the body far more than normal metabolism does. It found that a cautious heat-based limit would land close to the much stricter Soviet limit. | VC06, VC07, XC01 | T3 | MED |
| CLM-1335 | In the 1970s most city dwellers in the US received radio-frequency exposure more than a hundred times below even the strictest heat-based limits the note considered; only people next to big transmitters came close. | VC07, XC01 | T3 | MED |
| CLM-1336 | An old reviewer's note says the US microwave limit came mainly from a heat-balance calculation for an average man, after an earlier limit ten times higher, and not from laboratory evidence of harm. | VC06, XC01 | T3 | LOW |
| CLM-1338 | A 1970 experiment found that microwave cataracts in dogs needed the lens to heat up: the same repeated doses that clouded a warm eye did nothing when the eye was kept cool. | VC06, XC01 | T2 | MED |
| CLM-1339 | A 1950s experiment found that 3 GHz microwaves have to be about four times stronger than infra-red heat before skin starts to hurt, because most of the microwave heat goes deeper than the nerves that sense pain. Pain began at about half a watt per square centimetre. | VC06, VC07 | T1 | MED |
| CLM-1340 | In an early-1960s US Air Force study, two dogs spent thousands of hours in a microwave beam of 20 milliwatts per square centimetre and showed no clear harm, though both put on less weight than expected. Two animals are far too few to show that the level is safe. | VC06 | T3 | MED |
| CLM-1341 | In a year-long experiment from the early 1960s, mice given a short daily microwave dose that warmed them by about 3 degrees lived as long as unexposed mice, but more of them showed testicular damage. A link with white-blood-cell cancers appeared in two comparisons and not in a third. | VC06 | T1 | MED |
| CLM-1342 | A US mouse study, with tests run in 1957 and published in 1961 or later, found that repeated short microwave doses too weak to warm the animals still made them put on a little extra weight. The authors argued that the safety limit of the day had been picked without a sound basis. | VC06 | T3 | LOW |
| CLM-1345 | A 1972 medical paper says sailors on a warship's signal bridge could stand in radar fields up to about five times the US limit of the day. Under the thinking of the time, they would still be below the level expected to harm the eye. | VC06, XC01 | T5 | LOW |
| CLM-1347 | In 1972 a leading American review said microwaves were only known to harm people by heating them. It called the evidence for other effects weak, so it argued against copying the far stricter Soviet limit. | VC06, XC01 | T2 | MED |
| CLM-1348 | People feel microwave warmth only at fairly high strengths: tens of milliwatts per square centimetre for a second or so on the forehead, and less if more of the body is exposed. Pain needs tens of times more. So feeling nothing does not mean a person is below the limit. | VC06, VC07 | T2 | MED |
| CLM-1349 | NASA's report does print how much electricity each design is credited with, in its cost tables, and its carbon figures follow from those amounts exactly. An earlier reading that it had left out one design's part-time operation was wrong. | XC03 | T0 | HIGH |
| CLM-1354 | Rats exposed most of every day for a whole pregnancy at about 200 W/m2, close to the 230 W/m2 design centre, had normal pups and normal grand-pups on the tests used. | VC06, XC03 | T3 | MED |
| CLM-1358 | At and below 180 W/m2, rats warmed slightly but less than they do from being handled, and they slept through it. At 360 W/m2, they had to use emergency cooling. | VC06, XC03 | T3 | MED |
| CLM-1359 | Rabbit eyes needed a local field more than six times the 230 W/m2 design centre, held for over an hour and a half, to form a cataract; repeated daily exposures at about four times the design centre did not cause one. | VC06, XC03 | T3 | MED |
| CLM-1360 | Mice kept 16 hours a day for four days in fields around and above the design centre showed no sperm damage, though modest direct heating of the testes did cause it. | VC06, XC03 | T3 | MED |
| CLM-1361 | The same lab that once reported microwaves made mice grow faster repeated the test properly and found no effect, and said its earlier result should not be relied on. | VC06, XC03 | T1 | MED |
| CLM-1362 | Two hours a day at about 100 W/m2 warmed rats by about a degree and shifted blood counts for a while, without lasting harm on the tests used; 500 W/m2 overheated them quickly. | VC06, XC03 | T1 | LOW |
| CLM-1363 | With an aircraft's own radar aimed at the cockpit, the metal front of the fuselage kept the cockpit below what the meter could detect. | VC06, XC01 | T3 | MED |
| CLM-1364 | Inside a radar aircraft in flight, crew areas got under a thousandth of the old limit from the big radars; the one weak spot was a glass dome next to a radio antenna. | VC06, XC01 | T3 | LOW |
| CLM-1365 | The paper's biggest design is a laser array 10 km across that would push a sail a metre wide, carrying a chip of about a gram, to a fifth of light speed in ten minutes. It would then reach the nearest star in about 20 years. | VC05 | T2 | MED |
| CLM-1366 | The paper plans to build up in stages. Small ground lasers come first, then a 1 km array in orbit, and only at the end the 10 km array that its star-flight numbers assume. | VC05 | T2 | MED |
| CLM-1367 | A long spinning cable in low orbit dips its end down to 150 km, grabs a cargo pod from a very fast plane, and flings it towards a high orbit. | VC10 | T3 | MED |
| CLM-1368 | The study found a 600 to 900 km cable works best. Shorter ones jerk the cargo too hard, longer ones get too heavy. Its first design spun faster than it needed to. | VC10 | T3 | MED |
| CLM-1369 | The design is a ribbon about 100,000 km long, fixed to a sea platform near the equator, that stays over the same spot as the Earth turns. Without avoidance, something in orbit would hit it about once a year. | VC10 | T3 | MED |
| CLM-1370 | The cable needs a material about 30 times stronger than steel. In 2003 only carbon nanotubes looked able to get there, and real fibres were nowhere near yet. | VC10 | T3 | MED |
| CLM-1371 | A 1977 NASA design study planned a 10 km electromagnetic track on the Moon to fling small blocks of lunar rock into space at 2.4 km/s, about a million tonnes a year, as raw material for a space colony and the solar power satellites it would build. | VC11 | T3 | MED |
| CLM-1372 | The 1977 NASA design was a wheel-shaped habitat about 1.8 km across, with the living space inside a 130 m wide ring, spinning once a minute so people feel normal weight. A long cylinder of the same radius was also sized, and would hold far more people. | VC11 | T3 | HIGH |
| CLM-1373 | Two years after SP-413, a later NASA study's optimised Moon launcher was far shorter, about half a kilometre, because it accelerated at 1000 g instead of 30 g. It would throw about 42 kg a second at lunar escape speed. | VC11 | T3 | MED |
| CLM-1374 | A 1979 NASA paper let small, hand-picked crews live in faster-spinning habitats (3 turns a minute), but held large settlements of ordinary people to 1 turn a minute or less, to avoid motion sickness. | VC11 | T3 | HIGH |
| CLM-1377 | The official 2023 text that plans the 2031 world radio conference marks the wireless power item as not yet settled. It also says the whole agenda will be reconsidered in 2027, because countries disagreed about which frequency bands to study and how to protect existing radio users. | XC01 | T1 | HIGH |
| CLM-1378 | The 1981 report found online is by the same author about the same heating experiments, but it is not the 1979 memo the 1980 government report relied on. In it, the temperature figures are calculations, not measurements, so it cannot stand in for the missing measurement. | VC06 | T3 | MED |
| CLM-1379 | ESA's current life-cycle guidance tells analysts not to use the spending-based method for space hardware, because it seems to overstate environmental impact in the space sector. | XC03 | T3 | HIGH |
| CLM-1380 | NOAA's storm levels G1 to G5 correspond to the Kp disturbance index reaching 5, 6, 7, 8 and 9. | VC09, XC02 | T3 | HIGH |
| CLM-1381 | NOAA's own table confirms the storm-day counts the register was using: about 130 strong, 60 severe and 4 extreme storm days in an average 11-year cycle. | VC09, XC02 | T3 | MED |
| CLM-1382 | At its 2025 year end the UK company Cassiopeia Solar owed slightly more than it owned. Its main asset was about 251,000 pounds of patent costs, and it had four staff on average. | XC02, XC05 | T1 | HIGH |
| CLM-1383 | Almost all of what Cassiopeia Solar owes is owed to other companies in its own group, which the accounts do not name. | XC02, XC05 | T1 | HIGH |
| CLM-1384 | The company has spent about 295,000 pounds on patents, which it writes down over 20 years, and added about 15,000 pounds in the last year. | XC02, XC05 | T1 | HIGH |
| CLM-1385 | The Government's formal reply to the 2025 Lords report on UK space policy does not mention space-based solar power. None of the committee's 40 recommendations, as the reply reprints them, is about it either. | XC01 | T1 | MED |
| CLM-1386 | Great Britain's grid rules put any generator joining the network at 110,000 volts or more into their top class, Type D. A gigawatt ground receiving station would join at 275,000 or 400,000 volts, so it would be Type D. | VC08, XC01 | T1 | MED |
| CLM-1389 | Getting a kilogram into orbit has become more than 20 times cheaper since 1960, and the study finds the cost falls by about a fifth every time the total mass ever launched doubles. | VC10, XC02 | T2 | MED |
| CLM-1390 | The study expects launch to keep getting cheaper, to about a tenth of today's average by 2040, but says market power and space debris could slow that. | VC10, XC02 | T2 | MED |
| CLM-1398 | A 2022 survey of real US power plants found that, per unit of electricity, nuclear uses the least land and, of these six, wind farms use the most if the land between turbines is counted; if only the turbine pads and roads are counted, wind uses little land. | XC02, XC03 | T2 | HIGH |
| CLM-1399 | A US government lab found that a wind farm's whole site is about a hundred times larger than the land its turbines and roads actually cover. | XC03 | T3 | HIGH |
| CLM-1407 | Most designs turn their solar panels to face the Sun and their antenna to face the Earth, and pass the power across a turning joint between the two. CASSIOPeiA is meant to fix its panels and its antenna together and steer the beam electronically, so it needs no such joint. | VC04 | T3 | MED |
| CLM-1408 | In the late 1970s, US studies sketched receiving stations raised on posts or legs so the ground beneath could still be farmed or built on. They noted a trade-off: panels close to the ground are easier to reach for repairs. | VC07, XC03 | T3 | MED |
| CLM-1409 | A 1977 NASA study of how to hold up the receiving station's panels was told the ground underneath had to stay farmable, with a metal mesh of small diamond-shaped holes. It compared eleven ways of building it, some raised about 5 metres, high enough for farm machines underneath, and found the more usable the land below, the more the structure costs. | VC07 | T3 | MED |
| CLM-1410 | US government studies around 1980 thought crops might be grown under a receiving station, because its mesh lets most sunlight through and warms the ground only slightly. They also said it would make farming and repairs harder, needed design changes and had not been studied properly. One later survey suggested raising the station and screening the ground from microwaves, or building greenhouses under it. | VC07, XC03 | T3 | MED |
| CLM-1411 | In 1978 nobody knew whether animals could graze, or crops be grown, under or around a receiving station, because research on what its microwaves do to people and animals was not finished. | VC07, XC03 | T3 | MED |
| CLM-1412 | A 2022 study for the European Space Agency describes the receiving station as a fairly open grid of small antennas about 10 centimetres apart, which might let the land underneath be used for something else. It says the basic layout goes back to Raytheon and NASA in the late 1970s. | VC07 | T4 | MED |
| CLM-1413 | A 1977 NASA-funded report says the metal mesh behind a receiving station's antennas can be about three-quarters open to light while letting through only about half a per cent of the microwave power. The 1978 reference design used a steel mesh about that open. | VC07 | T3 | MED |
| CLM-1414 | The international nuclear agency's 2025 cost report counts the price paid for carbon emissions as part of what a kilowatt-hour costs, alongside building, running, fuelling and dismantling the plant. | XC02 | T3 | HIGH |
| CLM-1415 | The 2025 international cost report adds 50 US dollars for every tonne of carbon dioxide a fossil plant emits, the same everywhere, when it works out each plant's cost of electricity. | XC02 | T3 | HIGH |
| CLM-1416 | A 2022 study for the European Space Agency put the cheapest case for space solar power at about 55 euros per megawatt-hour after adjusting for the value of its electricity, under optimistic costs, a 10% cost of capital and a 30-year life. | XC01, XC02 | T4 | MED |
| CLM-1418 | The standard ground sunlight used to test solar cells adds up to about 1,000 watts per square metre, or 1 kilowatt, on a surface tilted towards the sun, under one fixed set of atmospheric conditions. It is a reference value, not what any site receives. | VC01 | T0 | MED |
| CLM-1419 | The Royal Society worked out that a British power system running only on wind and sun, with stored hydrogen to cover calm and dark spells, could supply electricity in 2050 at an average of 52 to 92 pounds per megawatt-hour in 2021 money. Most of that cost is the wind and solar power itself. | VC09, XC02 | T3 | MED |
| CLM-1420 | In the Royal Society's model, only about 15 per cent of Britain's electricity in 2050 comes out of storage, so the price of storage moves the average cost little. Each unit that does come out of storage costs many times more than wind or solar power used straight away. | VC09, XC02 | T3 | MED |
| CLM-1421 | A 2016 Imperial College study run jointly with three renewable-energy companies found that adding wind to Britain's grid in 2030 would bring extra system costs of about 5 to 9 pounds for each megawatt-hour the wind farms produce, compared with adding nuclear, if the grid has a fair amount of storage and other flexibility. Most of that extra cost is back-up power stations for windless periods. | VC09, XC02 | T4 | MED |
| CLM-1422 | Imperial College found that the extra system cost of wind and solar in Britain in 2030 depends heavily on how flexible the grid is: about 40 to 48 pounds per megawatt-hour of their output with no new storage or demand response, but about 5 to 17 pounds once those are added. The figures are measured against nuclear power, not counted from zero. | VC09, XC02 | T4 | MED |
| CLM-1423 | The UK's climate advisers said in 2019 that fitting large amounts of wind and solar power into the grid adds roughly 10 to 25 pounds to each megawatt-hour they produce, when wind and solar supply up to about half to two-thirds of the year's electricity. They also said there is little UK evidence for shares above about a third. | VC09, XC02 | T3 | MED |
| CLM-1424 | The UK's climate advisers broke the extra cost of wind and solar into parts: backup power for peak demand, wasted output and keeping spare plant running, and new power lines. They warned that the parts overlap, so they cannot simply be added up. | VC09, XC02 | T3 | MED |
| CLM-1425 | The UK's climate advisers estimated that a nearly carbon-free power system in 2050 would cost about 4 billion pounds a year more than one built on gas, and that the cost of coping with changeable wind and sun is under a tenth of the total. | VC09, XC02 | T3 | MED |
| CLM-1426 | The UK government estimated in 2020 that a wind or solar farm opening in 2030 brings wider grid costs, compared with a nuclear plant, of between about minus 5 and 17 pounds per megawatt-hour of its output, plus up to 13 pounds for transmission lines, depending on the farm type and on how the rest of the system is built. The figure grows for offshore wind built later. | VC09, XC02 | T3 | MED |
| CLM-1427 | The UK government says its 2020 figures for the wider grid cost of each type of power station show how one small extra plant would change costs, compared with a nuclear plant. They are not the total cost of running a whole power system, and they change with the rest of the system. | VC09, XC02 | T3 | MED |
| CLM-1428 | Britain's grid operator estimated that the cheaper of its two plans for a clean power grid in 2030 would cost about 126 pounds for each megawatt-hour used, in 2024 money, a little more than a plan that misses the climate targets, though NESO calls the costs of all the options similar within the bounds of uncertainty. It counts the capital cost of new plant and grid built since 2023, plus running, fuel and carbon costs, but not the capital cost of plant already built. | VC09, XC02 | T3 | MED |
| CLM-1429 | A search on 13 October 2026 found no published model of Britain's power system that is free to decide how much space solar power to build. One British government study valued small space solar plants in a model by scaling down a much larger assumed plant; the only free-choice model found covers the whole of Europe. | VC09, XC02 | T0 | MED |
| CLM-1430 | Put in 2024 money, a reliable British grid built on wind, sun and stored hydrogen would cost about 61 to 107 pounds per megawatt-hour in 2050. Set against the top of that range, the UK government's space solar study comes in at about half, and NASA's study, rebuilt in 2024 money, at nearly nine times. The two sides are costed differently, so this is a rough guide, not a like-for-like price comparison. | VC09, XC02 | T0 | MED |
| CLM-1431 | In the first week of November 2024 the wind was light: wind made a tenth of Britain's electricity supply, against almost 30 per cent over the year, and gas made half. | VC09, XC02 | T0 | HIGH |
| CLM-1432 | Rockwell's chart puts a price in mass on a flatter antenna. The frame for the 1,000 m radius weighs about 85 tonnes if it may deviate by 48 cm and about 226 tonnes if only 12 cm is allowed. The 500 m frame goes from about 16 to about 30 tonnes over the same range. | VC04, VC06 | T3 | MED |
| CLM-1433 | In the 1975 study, at 300 dollars a kilogram to launch and assemble, a 1 GW station cost about 1.7 to 3.5 times as much per kilowatt as a 20 GW one. The large stations were cheapest at about 1.25 to 2.25 GHz, but their curves are shallow: about 1,900 to 2,300 dollars per kilowatt across the whole band for the largest. | VC06, XC01 | T3 | MED |
| CLM-1434 | With launch and assembly at a third of the price and a cheaper power source, the 1975 study's costs per kilowatt fall at every size, by about 40 per cent for 1 GW and about two thirds for 20 GW. The largest stations still sit at their cheapest between about 1.5 and 3 GHz, around 610 dollars per kilowatt for 20 GW. | VC06, XC01 | T3 | MED |
| CLM-1435 | In NASA's design, rebuilt in 2024 money, cutting the launch price to a tenth while keeping everything else the same lowers the cost from about 930 to about 340 pounds per megawatt-hour. That is still about three times the top of the Royal Society's modelled 2050 cost range (about 61 to 107 pounds per megawatt-hour) for a British grid built on wind, sun and stored hydrogen. The UK government's study, for a mature fifth-built satellite, gives about 25 and 67 pounds per megawatt-hour for its low and high launch costs. The two sides are costed differently, so this is a rough guide, not a like-for-like price comparison. | VC09, XC02 | T0 | MED |
| CLM-1436 | A UK study says that one space solar power system would typically deliver about 2 gigawatts to the grid, and it compares this with the output of a nuclear power station. | VC09 | T4 | MED |
| CLM-1437 | A satellite in geostationary orbit, about 36,000 km up, goes round the Earth once in the time the Earth takes to turn once, which is just under 24 hours. So it stays over the same spot on the ground. | VC10 | T0 | MED |
| CLM-1438 | The ring of geostationary orbit lies over the Earth's equator. That ring is tilted by about 23.4 degrees to the flat plane in which the Earth travels round the Sun. So for most of the year the Sun is above or below the ring, and it lines up with the ring only around the two equinoxes. | VC04, VC10 | T3 | MED |
| CLM-1439 | Microwaves, radio waves and visible light are the same kind of thing: electromagnetic waves. What sets them apart is the length of the wave. Light waves are less than a thousandth of a millimetre long, microwaves are from a few millimetres to about a metre long, and broadcast radio waves are longer still. | VC06 | T2 | MED |
| CLM-1441 | Documents give the size of the CASSIOPeiA satellite design as anything from 1 to 2 km across. For a full-size version delivering 2 gigawatts from geostationary orbit, the best supported figure is about 1.7 km, from a 2021 study for the UK government. A 2020 report gives 1.6 km and credits the designer's 2019 paper, but that paper gives 1.6 km only as a general minimum for any such antenna at one radio frequency, not as this design's size. None of these is a measured size: the satellite has not been built. | VC04, VC05 | T4 | MED |
| CLM-1442 | A 2021 study for the UK government shows one design, CASSIOPeiA, as about 1.7 km across and 2,000 tonnes, sending 2 gigawatts to the grid from 35,786 km up. Its scale drawing puts it beside the world's tallest building, the 830 m Burj Khalifa, and the satellite is about twice that height. It is a design, not a built satellite. | VC04 | T4 | MED |
| CLM-1443 | The 2021 study for the UK government says the leading designs need no new materials, but that building them at a sensible cost needs two things that are not yet mature: robots that assemble large structures in orbit, and cheap reusable rockets. It says both are developing fast, that the whole system is at an early stage with considerable engineering risk, and that a programme of design and technology demonstration could address that risk. | VC10, VC11 | T4 | MED |
| CLM-1444 | The 2021 study for the UK government concluded that space-based solar power is technically feasible, affordable at a competitive cost per unit of electricity, and good for the UK economy, and recommended a staged programme of development and demonstration. This is the study's own conclusion; no such system has been built or tested at scale. | XC02 | T4 | MED |
| CLM-1445 | The 2021 study for the UK government reports that supporters of space solar power say it has become workable and affordable in the last ten years, after long being seen as attractive but too expensive. The study lists five reasons for the renewed interest: the push to Net Zero, launch costs that have fallen sharply and are expected to keep falling, modular designs built for mass production, maturing solar cells, wireless power and space robots, and other countries' strategic interest. It gives no figures for these on that page. | VC10, XC02 | T4 | MED |
| CLM-1446 | The 1977-80 US government programme did not decide for or against power satellites. It said questions on technology, environment and cost were still open, that a satellite would cost more to build, and less predictably, than conventional power stations, but that the range of its electricity costs was similar to that of other new options of the time, fusion and solar cells. A separate 1981 review for the US Congress said too little was known to decide, that the basic technologies had been shown to be feasible except lasers, and that, except perhaps for fusion, the up-front cost would be much higher than for other large power stations. | XC02, XC03 | T3 | MED |
| CLM-1448 | In 1979, the planners of a space solar power programme expected launch to low orbit to cost about 140 dollars a kilogram in today's money, on a large rocket they planned to fly hundreds of times. A 2026 study puts the average cost over all launches in 2025 at about 3,900 dollars a kilogram in today's money, about 28 times as much. The two numbers are different kinds of figure: one is a forecast for one planned rocket, the other an average over every rocket that flew that year. | VC10, XC02 | T0 | MED |
| CLM-1449 | Britain's solar panels make far less power in winter. In December 2024 they made about a ninth as much as in June. On the worst day of 2024, in late November, they made less than a seventieth of what they made on the best day, in early June. Even within December, the worst day gave about an eighth of the best. | VC09, XC02 | T0 | HIGH |
| CLM-1450 | SpaceX's price sheet lists a Falcon 9 launch at 74 million dollars, and 22,000 kilograms as the most it can carry to low orbit if the rocket is not recovered. Using those listed figures with the US study's own way of counting the extra launches needed to reach the power station's orbit gives a cost per kilogram about four times what the US study's own assumptions give, and the UK study's lowest input would need launches about ninety times cheaper than that listed figure. Both studies turn to electric propulsion for part of the climb, NASA only in the case where it finds a competitive cost, and this has not been shown at power-station scale. | VC10, XC02 | T6 | LOW |
| CLM-1452 | By our rough arithmetic, the beam of the UK's full-size reference design would carry about a million times more power than the power-beaming tests checked here that have a stated power: a Chinese ground test in 2022 that sent about 2 kilowatts across 55 metres, and two figures of about a kilowatt reported in the press in 2026, one for a Japanese satellite that is planned and not shown to have flown (a Japanese space agency researcher's 2025 lecture shows the same plan) and one for another Chinese ground test. At the design's peak beam strength, such a test could cover less than ten square metres, against tens of square kilometres for the design, so none of these tests comes close to the full-size beam that the worry about disturbing the upper atmosphere concerns. No output power is stated in the documents held here for a third test, a US Air Force flight test that nothing held shows has launched. | VC06, XC03 | T0 | MED |
| CLM-1453 | A 2021 UK study estimated what it would cost to carry satellites to high orbit on two reusable launchers: 3,260 dollars a kilogram for SpaceX Starship and 1,340 pounds a kilogram for the British SABRE spaceplane. The study does not set the two side by side in one currency, but converted at any of the exchange rates it lists, the Starship figure is the higher. The cost range its model actually uses runs from 358 to 2,410 pounds a kilogram. | VC10, XC02 | T4 | MED |
| CLM-1454 | The 2020 international limit for public exposure, 10 watts per square metre, is about 19 to 42 times lower than the beam strengths at which one theory says the beam might start to focus itself in the upper atmosphere (42 times uses a 2008 estimate, 19 times uses measured conditions), and 23 times lower than the 230 that a 2019 CASSIOPeiA paper gives as a typical peak. Those atmospheric figures are estimates, not hard limits. A 2026 international radio report that takes CASSIOPeiA as its example says the beam can be designed to fall below the public limit at the edge of the receiving site, with a safety zone over the beam's footprint; it gives no figure for the beam's strength at that edge, and a diagram in it shows the receiving site taking 245 watts per square metre. | VC06, VC07, XC01 | T3 | MED |
| CLM-1455 | A Member of Parliament who, by his own declarations, chaired the advisory board of the Space Energy Initiative and was a non-executive director of Space Solar used House of Commons debates in April 2024 and June 2025 to argue for UK government support for space-based solar power, declaring these as unpaid interests each time. The government minister who replied in June 2025 did not promise any money specifically for space-based solar power. | XC01 | T5 | HIGH |
| CLM-1456 | Japan's government roadmap for space solar power, written in 2006 and revised in 2016, as shown in a December 2024 report, planned a decision on a space demonstration around 2025, a demonstration satellite around 2030, and a commercial system around 2045 to 2050. All of these were plans, not achievements. The same report notes that its earlier record of up to 100 metres was 0.0003 percent of the 36,000 kilometres a real system would need (by our arithmetic, the 5 kilometres it planned to fly is about 0.014 percent), and gives its next step as a transmission from low Earth orbit, dated only as 2025, to be decided. | XC01 | T4 | MED |
| CLM-1457 | A 2021 study for the UK government of the CASSIOPeiA space solar design used two discount rates for two questions: a tough 20 percent, the return it assumed private investors would want, for its cost of electricity, and the government's standard rate at the time, 3.5 percent, for judging whether the whole programme would be worth it for the country. It does not show that pairing the two is standard for other power stations. | XC01, XC02 | T4 | MED |
| CLM-1458 | The 2019 paper behind CASSIOPeiA's 1 kW/kg figure lists six modelled design variants, and only the two with the most concentrated sunlight reach that figure; the other four come in at 0.79 to 0.95 kW/kg. The paper does not show where the mass goes, and its statement that the design's operating principle was independently validated cites nothing and does not say what the check covered. | VC04 | T2 | MED |
| CLM-1459 | A 2013 design study for a large constellation of solar power satellites proposes that each one climb to its final orbit on electric thrusters powered by a separate, smaller set of solar panels rather than its main panels, which stay folded during the long trip to limit exposure to space weather and debris. The study expects the separate panels to be damaged on the way and reuses them afterwards to help keep the satellite pointed. | VC04, VC11 | T5 | LOW |
| CLM-1460 | When a US military satellite's main engine for climbing to its high orbit failed in 2010, press reports from 2010 and 2012 say its small chemical thrusters and then its electric thrusters lifted it the rest of the way; on their dates the electric thrusters were in use for about a year, two months longer than the recovery plan expected, and the satellite reached its final orbit about 14 months after launch. | VC10 | T5 | LOW |
| CLM-1461 | A 1981 computer model predicted that a space solar power beam would make electrons in the lower ionosphere two to three times hotter and change their number by up to half, and the study found that radio measurements during ground-based heater tests in Colorado broadly matched its model, though by day the heater could not reproduce the beam's full effect at the greater heights. A 1980 US government report said measurements during the Colorado tests showed the electrons' temperature changing while the heater was on, and that calculations by the same lead author matched another researcher's figure for how far such a heater can raise it; the memo behind that figure is not held, so whether it was measured cannot be checked. | VC06 | T3 | MED |
| CLM-1462 | A 2020 paper's finding that its detailed method gave five to six times the carbon of an earlier, simpler study of the same 1978 design compares a carbon-dioxide-only figure with a figure that also counts other greenhouse gases, and the paper labels the earlier figure two different ways in two places. | XC03 | T5 | LOW |
| CLM-1463 | If each antenna in a row starts its wave a moment after its neighbour, the beam leans away from straight ahead. The size of the lean follows from three things: how big the time step is, how fast the waves travel, and how far apart the antennas are. A bigger step, or closer antennas, gives a bigger lean. | VC05 | T0 | MED |
| CLM-1464 | Adding antennas to a row that all send together does two things. The beam gets narrower, and it gets stronger straight ahead: twice as many antennas give four times the strength in that direction. A row 16 antennas long, half a wave apart, makes a beam about 6 degrees wide. | VC05 | T0 | MED |
| CLM-1465 | If the antennas in a row are spaced too far apart, extra beams as strong as the main one go out in other directions. How close they must be depends on how far the beam is swung. Unswung, up to a whole wavelength apart is safe. Swung 30 degrees, the antennas must be closer than two-thirds of a wavelength. | VC05 | T0 | MED |
| CLM-1466 | The pilot method works out of each antenna's own measurement, not out of a plan of where the antennas should be. Each antenna times its reply from when the pilot reached it. So if one antenna has moved, its timing changes by just the right amount, and all the replies still arrive together where the pilot came from. A 1980 NASA memorandum set out the principle; it does not discuss a moved antenna, but its working covers one. | VC05, VC06 | T3 | MED |
| CLM-1467 | Keeping people out of the area where the beam is strong is a plausible way for a strong beam to meet the 2020 international limit for public exposure, and international exposure guidance accepts limiting access as a way to comply. Other designs have worked this out: a 2013 Japanese review plans a no-entry area 3.5 kilometres across, and a 2007 international study sizes a 4-kilometre receiver this way. A 1977 US study set aside 204 square kilometres for one receiving site, without saying in its cost table what fixed that size, and costed buying and preparing that land. A 2026 international radio report that takes CASSIOPeiA as its example says the beam can be designed to fall below the public limit at the edge of the receiving site, with a safety zone matching the beam's footprint, about 3.5 to 6.5 by 7 to 13 kilometres in the UK. A diagram in it shows the receiving site taking 245 watts per square metre, but the report gives no figure for the beam's strength at the edge and no cost for the zone. A 2021 UK cost model for a CASSIOPeiA design includes the land for the receiving site but names no safety zone. | VC06, VC07, XC01 | T4 | LOW |
| CLM-1468 | The basic idea, a solar power satellite climbing to its final orbit on electric engines run by solar panels it carries, with no separate fuel tanker, is real: it has flown on communications satellites, though not at the scale of a power station. A 2013 design does it with a separate, smaller set of panels. The stronger version, where the satellite's own main panels run the engines, has been proposed, for example by a 1977 US study, which found the panels used for the trip would be badly damaged on the way, and by a 2021 UK study for the last part of the climb only, after chemical stages carry the parts past the inner radiation belt. None of these designs has flown. | VC04, VC10, VC11 | T0 | MED |
| CLM-1469 | In the Royal Society's model of a British power system run on wind and sun in 2050, electricity fed into the grid costs about 1.7 to 2 times what the wind and solar power itself costs. At the cheap end, the electricity costs about 1.7 times what the wind and solar power itself costs. At the expensive end it costs about twice as much. | VC09, XC02 | T3 | MED |
| CLM-1470 | Britain's capacity market does not count gas or nuclear power stations at their full size. It counts a gas plant at about 88 to 92 per cent of its capacity, and a nuclear plant at about 75 to 85 per cent. Government advisers say the nuclear figure now rests on too few plants to be reliable. | VC09, VC12 | T3 | MED |
| CLM-1471 | Britain's nuclear power stations were not running at full output for much of the time. From 2012 to 2022, planned and unplanned shutdowns cost the older reactors about a fifth to a third of the electricity they could have made, and the newest, Sizewell B, about a seventh. | VC09, VC12 | T3 | HIGH |
| CLM-1472 | The designer of the UK's CASSIOPeiA satellite says it has no moving parts and is built from many small identical pieces, so when pieces fail it loses power gradually rather than stopping. It is meant to run for 20 years or more with no planned repairs. A 2020 UK government study repeats this and treats the satellite's upkeep as a slow loss of power rather than a repair bill. | VC05, VC12 | T4 | MED |
| CLM-1473 | A 2020 UK government study expects early test satellites to be left to wear out slowly. For full-size satellites, it assumes robots would swap out faulty modules, using the same robots that built the satellite. Those robots do not exist yet. NASA's 2024 study instead plans to replace all of a satellite's hardware every 10 years. | VC12 | T4 | MED |
| CLM-1474 | One UK study designs small power satellites that beam to receivers in Scotland, Canada and Japan, switching between them as they move along their orbit. Each satellite beams to one receiver at a time, and the UK receiver comes first when both are in view. | VC07, VC09 | T4 | MED |
| CLM-1475 | Some writers point out that a power satellite is not tied to one receiver: in principle it could beam to a different site, for example if a military base moved. No study held here tests this or uses it to cover a receiver that is out of action. | VC09 | T3 | LOW |
| CLM-1476 | The European study states that it used a 3 per cent interest rate for the cost of the space solar satellites. It does not say, in the paper itself, what rate it used for wind, solar and the other power sources, so it is not possible to tell from the paper whether space solar was given an easier test than its rivals. | VC09, XC02 | T2 | MED |
| CLM-1477 | The UK government's 2021 cost study for a power satellite assumes that parts fail and wear over the satellite's life, costing it between nothing and a quarter of a per cent of its output each year. | VC12, XC02 | T4 | MED |
| CLM-1478 | Almost everything that can go wrong with this design makes the beam fall apart and become harmless, which is the right way to fail. Two things do not. If someone fakes the ground signal, the satellite aims at the fake. And if the internal reference cabling drifts, the beam weakens and wanders rather than switching off. | VC05, XC04 | T0 | MED |
| CLM-1479 | A 1981 NASA summary says that if the timing across the 1978 design's antenna were lost, its beam would spread out to the width that one of its small radiating sections makes on its own, covering a very large area. Far from the receiving site the power could rise, but the summary says it would stay well below even the strictest safety limits of the time. | VC05, VC06, XC01 | T3 | MED |
| CLM-1480 | A 1981 survey for the US energy department says that a beam steered by a signal from the ground cannot form without that signal. If the signal fails, the antenna's parts fall out of step, the power spreads over half the sky, and what reaches the ground is as weak as a radio signal. The survey takes this to mean the beam could not be aimed anywhere except at the signal. | VC05, VC06, XC01 | T3 | MED |
| CLM-1481 | Worked out from the 1978 report's own figures: if the design's thousands of antenna sections fall out of step, the beam does not fill half the sky. It spreads to a patch roughly 400 km wide, and the power in it, on average, is close to the report's own figure for that case, several thousand times weaker than at the centre of the working beam. | VC05, VC06 | T0 | MED |
| CLM-1482 | A 2007 report by the international radio science union, answering whether a power satellite would be safe, says government rules let a microwave oven leak up to 5 milliwatts per square centimetre, and that Japan allows 1 milliwatt per square centimetre measured 5 centimetres from the oven. | VC06 | T2 | MED |
| CLM-1483 | US rules in force in October 2026 set how much a microwave oven made since late 1971 for homes, restaurants and similar places may leak: measured 5 centimetres or more from its outside, no more than 1 milliwatt per square centimetre when new, and no more than 5 at any later time. | VC06 | T1 | MED |
| CLM-1485 | The patent behind the CASSIOPeiA design, both the 2018 application and the granted patent published in 2021, mentions 230 watts per square metre in passing as an ideal and safe figure while describing the design. Neither version sets out to show that the figure is safe, and neither cites any safety standard. | VC06, XC01 | T3 | HIGH |
| CLM-1486 | A 1977 NASA study of how receiving stations would join the US power grid looked at two kinds of shadow. For about six weeks around each equinox, the Earth would shade each satellite once a night near midnight; the study judged this easy to cover, because demand then is about half its peak. If more than a hundred satellites were built, they would also shade each other each morning and evening, close to peak demand. By the study's table, that would cut the number of five-gigawatt receiving stations the US grids could take in 2025 from about 360 to about 60. The study added that direct-current links between the regional grids would largely remove the problem, but gave no figures for that. | VC08, VC09 | T3 | MED |
| CLM-1487 | In Britain, the amount of fast back-up power kept ready depends mainly on the biggest single block of power that could be lost at once; the rules do not set it by fuel. So a space solar station would need about the same fast back-up as a gas power station whose biggest single loss is the same size. A 2 GW space plant would be a bigger single loss than the 1,800 MW Britain now plans for, if one fault could take all of it. A satellite in geostationary orbit also passes through the Earth's shadow each night for about six weeks around each spring and autumn equinox, for up to about 70 minutes. Those times can be predicted exactly, and other power stations would have to cover them. | VC08, VC09 | T3 | MED |
| CLM-1488 | A Royal Society report on storing electricity in Britain, drawing on the Met Office, says a spell of very low winter wind lasting up to a week comes every few years, and a calm summer spell of up to four weeks once every ten years. But in its model of a 2050 grid run on wind and sun, the biggest drain on the store came in the weather of 2009 to 2011, a run of low-wind years. The report warns that studies of single years, or of only the worst spells, can badly underestimate how much storage is needed. | VC09, XC02 | T3 | MED |
Tier is how direct the evidence is and confidence is how strongly the record is held; neither is a quality score. What each tier means.