Value chain · CLM-0138
In plain terms
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.
The claim as recorded
The official 1978 DOE/NASA MPTS efficiency chain (DOE-ER-0023, Figure 25, p.56) multiplies DC-RF conversion (0.85) by transmit-antenna/pointing tolerance (0.985 x 0.98 = 0.9653) by atmospheric loss (0.98) by rectenna collection (0.89) by RF-DC conversion (0.88) to reach an overall 63%, with no term anywhere in the chain for ionospheric scattering loss.
Scope and limits
Shows the reference design treated ionospheric scattering loss as zero by omission, not that a calculation was done and found it to be zero. Does not establish that 63% is achievable or was ever demonstrated. THE SOURCE CONTRADICTS ITSELF ON THE TWO RECTENNA TERMS, and this record transcribes the labels as printed. DOE-ER-0023's own stage power levels are 6.58 -> 5.79 -> 5.15 GW. 6.58 x 0.88 = 5.7904, matching the printed 5.79 exactly, while 6.58 x 0.89 = 5.8562 does not; the two step ratios are 0.87994 then 0.88946. So the design values are collection 0.88 and rf-dc conversion 0.89, the reverse of the printed labels. SRC-107 (NASA RP-1076, 1981) Table III-1 prints the same power levels with the labels the other way round and states the same 790 MW and 640 MW stage losses, which the subtractions confirm. The 63 per cent overall product is unaffected, because the two terms multiply. Recorded 2026-09-05 by the source-retrodiction pass and the arithmetic re-checked independently. The transcription is faithful; the defect is the source's, which is a different defect from a claim misreporting its source and has a different fix.
What it assumes
The chain as reported accurately reflects the full efficiency breakdown in DOE-ER-0023; no other page of that 322-page report was found to add a scattering term.
Where it comes from
DOE-ER-0023 (1978), Figure 25 "Microwave Transmission Efficiency," p.56: terms as listed above, 63% overall; 23 mW/cm2 threshold stated p.41 as protecting third-party communications systems and the uplink pilot beam, not as a costed loss to the downlink beam itself.
Basis: fraction (dimensionless), DC-to-rectenna-DC-output efficiency chain
Related records
- Answers question
- QST-001 not published in this release
Cite this
energyaperture.com/c/clm-0138
CLM-0138, Energy Aperture, as of 1978.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-085
- CLM-0013The paper that modern UK studies rely on for the beam figure calls anything below 1 kilowatt per square metre safe, with 230 watts per...CLM-0020The 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...CLM-0023In the 1978 reference design, two limits set the size of the transmitter and the receiving site: how much heat the transmitter can shed...CLM-0039The 1978 report set the figure to protect radio and navigation systems from a disturbed ionosphere, called the number theoretical and...CLM-0045The 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.CLM-0101The 1978 contract required the researchers to report fixes if ionospheric disturbance pushed the pilot-beam phase error past 2 to 3...CLM-0137In 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...CLM-0182When two different research teams assessed the exact same 1978 space solar power design, the older accounting method (which spreads...More on the source page.