Value chain · CLM-0964
In plain terms
To build two of these satellites a year, about 300 tonnes of material had to arrive at the orbital construction site every day. Getting it there was over a third of the whole cost.
The claim as recorded
The April 1980 DOE/NASA Program Review states that building two 35-million-kilogram 5 GW satellites per year requires approximately 300,000 kg per day delivered to the construction site in geosynchronous orbit, and that transportation is 35 to 40 per cent of programme cost.
Evidence behind this: T3-programme-review, the 1978 rate restated in mass terms two years later.
Scope and limits
A DELIVERY RATE, NOT AN ASSEMBLY RATE - but it is the throughput the assembly had to absorb. The apparent 1.56x excess over satellite mass recorded here on 2026-09-17 was an artefact of the source's own mixed sentence: against the silicon mass the rate was computed from, the excess is 6 per cent of supplies and propellant (SRC-532 B-9, CLM-1023 to CLM-1034). It must still not be presented as satellite mass per day. The 35 to 40 per cent transportation share is one Program Review paper's sentence (Wales, SRC-449 PDF p.215, printed 193), and its 722 HLLV flights a year is nearly twice the transportation volume's 375 (CLM-1023) without saying which satellite or payload it assumes; the same volume's cost tables give 24 per cent (Piland, Table 2: 2.8 of 11.5 per average unit) and 29 per cent (Johnson, Figure 1: 3.4 of 11.7), and 44 per cent of the development-plus-first-unit total (45.5 of 102.5) (CLM-1060, back-linked 2026-09-19).
What it assumes
AMENDED 2026-09-18. The 300,000 kg per day is the silicon reference system's GEO delivery: the JSC data book (SRC-532 Appendix B, table B-9) gives 104,008 t of SPS (two 52,004 t satellites, the 50,984 t silicon mass plus 2 per cent breakage) plus 1,251 t of GEO base supplies, 1,147 t of tug propellant and 4,070 t of POTV propellant, 110,476 t a year, 302.7 t a day. The "35 million kg" in the same sentence is the GaAs option's mass; the sentence pairs one option's mass with the other's delivery rate.
Where it comes from
PDF p.215, normalised: "The SPS program requirement for the construction of two 35-million kilogram (5- GW) satellites each year demands that approximately 300,000 kilogram (660,000 pounds) of mass per day be delivered to the construction site, at geosynchronous orbit. The transportation system represents a significant part of the overall program cost, from 35-40 percent."
Basis: 35 million kg per 5 GW satellite; two per year
Related records
- Answers question
- QST-003 not published in this releaseQST-015 not published in this release
Cite this
energyaperture.com/c/clm-0964
CLM-0964, Energy Aperture, as of 1980-04.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-449
- CLM-0974The 1978 reference design shows every loss between sunlight and the power grid as a chain of numbered boxes, and the boxes multiply out...CLM-0975Depending on which published assumptions you take, a satellite needs between about 2 and 6 square kilometres of solar blanket for every...CLM-1058The often-repeated claim that the magnetron is 188 decibels quieter than its carrier traces to a conference abstract in which the tube...CLM-1059By spring 1980 the engineers, the reviewing panel and the ionosphere experimenters were all saying the beam-intensity ceiling the whole...CLM-1060The 1980 review did not agree with itself on how much of a satellite's cost was rockets: one paper said over a third, the programme's own...CLM-1061In one 1980 volume the satellite cost anywhere from about 2,300 to 3,800 dollars a kilowatt depending on who added what - and the programme...CLM-1062In 1980 the launch vehicle that everything was costed on was said by its own designers to be arbitrarily big, and they proposed a rocket a...CLM-1063In 1980 the magnetron satellite was the lightest per kilowatt on paper and the most efficient tube on the bench, the klystron was the...More on the source page.