Value chain · CLM-0982
In plain terms
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.
The claim as recorded
The 180-day construction time per 5 GW satellite was a programme ground rule of the SPS Concept Development and Evaluation Program, not an engineering result. NASA's 1981 construction summary lists "One 5-gigawatt satellite is to be assembled in 180 days +/- 5 percent" as ground rule [2]; Boeing's 1979 operations volume states that "in order to satisfy the ground rule which limits GEO assembly of the 5GW satellite to 6 months, it was necessary to operate with skeleton crews, use minimal equipments and slow the operating rates of on-line beam machines"; Rockwell's 1979 volume states that its timeline "conforms to that schedule".
Evidence behind this: T3, the programme office and both prime contractors saying the same thing in terms.
Scope and limits
A GROUND RULE IS A PLANNING CONSTRAINT; THE SAME PAGE SHOWS THE DESIGN COULD GO FASTER. What is established is the provenance of the six months, not whether six months was achievable; SRC-466's Figure 12-58, construction time against beam rate, has not been rendered.
What it assumes
No assumptions are recorded against this claim.
Where it comes from
p.11, normalised: "[2] One 5-gigawatt satellite is to be assembled in 180 days +/- 5 percent." p.7: "constrain SPS final assembly and checkout to one satellite every 6 months." SRC-466 12-82, from the render: "End Builder Longitudinal Beam Production Capability - In order to satisfy the ground rule which limits GEO assembly of the 5GW satellite to 6 months, it was necessary to operate with skeleton crews, use minimal equipments and slow the operating rates of on-line beam machines... a significant reduction in overall construction time can be realized by simply operating these on-line machines a little faster, such as at 3.5 meters per minute rather than the 0.5 meters per minute as shown at 180 days" (the text layer renders 3.5 as "3. ::i"). SRC-457 4-15: "Current program ground rules specify a satellite construction rate of two per year over a 30 year period, or 180 days per satellite. The timeline in Figure 4.4-3 conforms to that schedule."
Basis: construction duration per satellite; programme ground rule
Related records
- Answers question
- QST-015 not published in this release
Cite this
energyaperture.com/c/clm-0982
CLM-0982, Energy Aperture, as of 1981.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-465
- CLM-0984The programme's own arithmetic for the antenna frame: each beam takes its length divided by five metres a minute plus twenty minutes to...CLM-0985By 1981 the programme put about four hundred people at the orbital construction base, with roughly two-thirds of them on the actual...CLM-0987They 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...
- Also from SRC-466
- CLM-0985By 1981 the programme put about four hundred people at the orbital construction base, with roughly two-thirds of them on the actual...