Value chain · CLM-1037
In plain terms
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.
The claim as recorded
NASA JSC's December 1980 sizing paper states that tests at Arecibo and Platteville "show no evidence to support 23 mW/cm2 as an upper limit", that electron temperature rises were "a factor of 2 or 3, rather than the order of magnitude predicted in the early analyses", that revised theory predicts 1/f^3 rather than 1/f^2 heating, that "an ionosphere power density level of 50-60 mW/cm2 may be a reasonable limit", and concludes that "the present ionospheric limit of 23 mW/cm2 is too low and should be raised after the ionospheric heating tests and studies are completed. Because of SPS cost considerations, it is very important to ascertain the true upper limit."
Evidence behind this: T3-programme office technical paper, citing a private communication for the Platteville result and "initial results" for the revised theory.
Scope and limits
THE PLATTEVILLE RESULT IS CITED TO "PRIVATE COMMUNICATION FROM C. RUSH, DEC. 1979" AND THE REVISED THEORY TO "INITIAL RESULTS"; the DOE assessment of the same year (CLM-1011 to CLM-1013) says the cube law was unvalidated and the F-region results uninterpretable. A programme office's position, not a measurement.
What it assumes
No assumptions are recorded against this claim.
Where it comes from
PDF p.21, raw: "show no evidence to support 23 mW/cm2 as an upper limit"; normalised: "a factor of 2 or 3, rather than the order of magnitude predicted in the early analyses (ref. 4)"; "An ionosphere power density level of 50-60 mW/cm2 may be a reasonable limit"; the 1/f^3 sentence transcribed across a hyphenated line break. PDF p.26, normalised: "The present ionospheric limit of 23 mW/cm2 is too low and should be raised after the ionospheric heating tests and studies are completed. Because of SPS cost considerations, it is very important to ascertain the true upper limit."
Basis: mW/cm2 at the ionosphere
Related records
- Answers question
- QST-001 not published in this release
Cite this
energyaperture.com/c/clm-1037
CLM-1037, Energy Aperture, as of 1980-12.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-556
- CLM-1036The programme's own sizing arithmetic, with its rate of return stated: in the cases studied a bigger antenna always raised the cost, but...CLM-1089The 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...