Value chain · CLM-1481
In plain terms
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.
The claim as recorded
If the 1978 reference design's 7220 subarrays, each about 108 m2, lose phase with each other but stay coherent within themselves, the ground pattern takes the shape of one subarray's beam: about 0.60 degrees wide at half power, which is about 370 km east to west below the satellite and about 390 km, stretched to about 510 km north to south, at 35 degrees latitude, with about 82 per cent of the power inside the first nulls, about 850 to 900 km apart east to west and about 1,150 km north to south at 35 degrees latitude; averaged over random phase sets, the computed peak, 0.0033 to 0.0038 mW/cm2 on a surface facing the satellite, is within about 1 dB of the report's own 0.003 mW/cm2.
Evidence behind this: T0: a closed-form estimate (CALC-144) on the 1978 report's own figures (SRC-085 PDF p.39, T3); the subarray shape is assumed square.
Scope and limits
An estimate from the report's figures, not the report's own calculation, and it says nothing about how fast the spread happens (CLM-1020). If phase were lost per tube, as RP-1076's "power module" could mean (CLM-1479), the patch would be wider: 750 km for a 27 m2 edge module and 2,240 km for a 3 m2 centre module at the equator, with a lower peak. The densities are on a surface facing the satellite; on flat ground at 35 degrees latitude they are about 0.76 of that. Real subarrays lose some gain to their 10 degree rms internal error and failed tubes (the phase error alone about 0.13 dB), which would bring the peak a little nearer 0.003. The densities are averages over random phase sets. With one fixed set of random phases the patch is speckled, in grains about 4 km across, with about 5 per cent of points above three times the average and the highest point in the half-power area typically about 9 times it (8 to 12 in nine sets out of ten), about 0.03 mW/cm2 (0.03 to 0.04), which is above the USSR guideline of 0.01; if the phases keep drifting, the grains move and the average over time returns to the figures above. The 1978 report does not say which happens. A 1978 design only: a design that keeps phase per element spreads far wider (CLM-0911 notes, CLM-1480).
What it assumes
Square, uniformly lit subarrays with no internal error or loss, so the gain is an upper bound; phase lost between subarrays and kept inside each, as SRC-085 PDF p.42 describes; the rectenna on the satellite's meridian; equal subarray beam shapes across the taper (the incoherent peak does not depend on the taper).
Where it comes from
This is the project's own working, shown in full:
CALC-144, its script run of 2026-10-21. Wavelength 0.12236 m; square subarray of side sqrt(108) = 10.392 m; half-power width 0.8859 lambda / D = 0.01043 rad (0.598 deg); gain 4 pi A / lambda^2 = 90,641. Peak = 6.72 GW x 90,641 / (4 pi R^2): 0.00378 mW/cm2 at 35,786 km (equator), 0.00352 at 37,120 km (35 deg), 0.00329 at 38,377 km (50 deg), that is +1.01, +0.69 and +0.40 dB against 0.003, and +1.07, +0.75, +0.46 dB against the plot reading 0.00296 (CLM-0911). East-west half-power width 373, 387, 400 km; north-south 373, 510, 741 km; first-null width east to west 843, 874, 904 km and north to south 843, 1,152, 1,673 km; 0.9028 of the power per axis inside the first nulls, 0.815 in all. For comparison, the whole 1 km antenna's gain in place of a subarray's gives 27.5 mW/cm2. One fixed random phase set (step 8, 1000 seeds, the 7,220 cells nearest the axis): 5.0 per cent of points in the half-power square above three times the average (4.6 to 5.4); highest point median 9.2 times the average peak, 7.6 to 11.6 in 90 per cent of sets, 0.035 mW/cm2 at nadir (0.029 to 0.044). The script's five gates pass, and two one-input mutants fail them.
Basis: 2.45 GHz; ground widths in km at the half-power points; power density in mW/cm2 on a surface facing the satellite
Related records
- Answers question
- QST-013 not published in this release
Cite this
energyaperture.com/c/clm-1481
CLM-1481, Energy Aperture, as of 2026-10-17.
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-0138The original 1978 government design for beaming power down from space adds up all the expected energy losses to get 63% overall efficiency...More on the source page.