Value chain · CLM-1039
In plain terms
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.
The claim as recorded
Both CDEP military assessments find that the microwave power beam is not itself a weapon. Ozeroff (1978) places every real weapon on lasers or particle beams the satellite might power, calls boost-phase anti-missile use "a rather remote possibility" needing "tens of gigawatts", and treats the beam only as a "psychological weapon"; Vajk (1980) states that a single captured beam's power "would be rather low", that "no biologically harmful effects of the SPS microwave beam are known", that focusing twenty satellites' beams on one point would give 460 mW/cm2, about 3.3 times peak solar flux as Vajk puts it (about 140 mW/cm2, which is sunlight above the atmosphere; against standard sunlight at the ground it is about 4.6 times), and only against targets in the same hemisphere as the intended receiver. Vajk names the capture mechanism - a "Pied Piper box" emitting an encoded pilot - and a "phase control box" that steers without a ground pilot, and lists the safeguards: pilot encryption, redundant pilots, frequency hopping, spread spectrum and a dual-key shutoff.
Evidence behind this: T3, the programme's two military assessments, two years and two contractors apart.
Scope and limits
1978-80 ASSESSMENTS; Ozeroff was unclassified by requirement and drew on "a minor portion" of classified sources; Vajk's 460 mW/cm2 is stated without shown arithmetic; neither computes a damage threshold for the beam. Vajk's Appendix C.4 finds every electronic attack on the phase control ends in defocusing, the fail-safe direction, but that is an analysis of the 1980 design's control loop, not a test. The same Vajk paragraph (PDF p.54) continues "If many beams could be captured simultaneously, the total microwave flux could reach incendiary levels", the sentence the twenty-satellite 460 mW/cm2 on printed 3-10 quantifies; the claim's "not itself a weapon" rests on the single-beam sentence, which gives the single beam a possible use in psychological warfare, as Ozeroff does; neither study says a single beam is harmless. The 3.3 times is Vajk's own ratio to the peak solar flux he puts at about 140 mW/cm2 and calls the value at the Earth's surface (PDF p.56, read at the render). About 140 mW/cm2 is the sunlight above the atmosphere (the 1,361 W/m2 solar constant CLM-0692 uses is 136 mW/cm2); at the ground the standard reference spectrum gives about 100 mW/cm2 (CLM-1418), against which 460 mW/cm2 is about 4.6 times (460 / 100 = 4.6; 460 / 140 = 3.3).
What it assumes
The 2.45 GHz, 5 GW, 23 mW/cm2 reference design.
Where it comes from
PDF p.14, normalised: "boost-phase kill from such an altitude may require laser beam power of the order of tens of gigawatts"; "an effective laser system at such altitudes must be considered a rather remote possibility"; PDF p.16: "it might be feasible to redirect the main microwave power beam away from its rectenna", as a psychological weapon inducing fear or panic. SRC-542 PDF p.54, raw: "rather low"; normalised: "No biologically harmful effects of the SPS microwave beam are known"; raw: "Pied Piper"; PDF p.56, raw: "460 mW/cm2", "same hemisphere"; PDF p.65, raw: "a phase control box which could control the SPS power beam, without a pilot beam from the ground"; PDF p.109, raw: pilot encryption, "frequency hopping", "spread spectrum", redundant pilots and a dual-key shutoff. Arithmetic: 20 x 23 mW/cm2 = 460, consistent with the stated figure.
Basis: mW/cm2 on the ground with beams combined; GW of laser power for a weapon
Related records
- Answers question
- QST-011 not published in this releaseQST-036 not published in this release
Cite this
energyaperture.com/c/clm-1039
CLM-1039, Energy Aperture, as of 1980.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-503
- CLM-1040The programme's first military study said the satellite could not be fully protected; its second said it was no softer a target than a...
- Also from SRC-542
- CLM-1040The programme's first military study said the satellite could not be fully protected; its second said it was no softer a target than a...CLM-1408In the late 1970s, US studies sketched receiving stations raised on posts or legs so the ground beneath could still be farmed or built on...