Value chain · CLM-1032
In plain terms
If the ferry's solar cells could not be repaired in flight it would wear out in three trips and the cost per kilogram would rise by about a third; thicker glass would fix that. A ten-minute delay restarting the engines every orbit cost more than the heat of being near Earth, and a chemical ferry would cost twice as much.
The claim as recorded
Boeing's 1980 EOTV sensitivity analysis finds that without solar array annealing "array degradation is so rapid that one may expect no more than 3 trips" and "the system cost with 3 trips was hand calculated as about 80/kg" against a reference-case total transport cost plotted at about 57 to 63 dollars per kg (1979) across 120 to 240 day trips, that 150 to 200 micron coverglass restores up to 10 trips, that Earth-proximity heating (40 to 70 C, about 8 per cent output) matters less than a ten-minute thruster restart delay after each shadow exit, which "increases LEO-to-GEO costs almost 10%", and that hydrogen MPD arcjets are a viable backup within about 10 per cent of the ion option if argon injection into the magnetosphere proves unacceptable; its bar chart puts a chemical OTV at about twice the reference EOTV's total transport cost on the same HLLV launch costs.
Evidence behind this: T3-contractor sensitivity analysis read from coarse 1980 plots; MED for that reason.
Scope and limits
Plot readings from renders of coarse 1980 computer plots; the 57 to 63 and 205 to 400 are approximate and should be quoted as ratios. The percentages on PDF p.115 / 109 (Isp correction factor about 0.78, trip time extended about 35 per cent) are letter-for-digit degraded in the text layer and were read from the render with less confidence than the rest.
What it assumes
That the plotted $/kg is the total Earth-to-GEO figure the diagram of Figure 4.5-2 defines ("PAYLOAD LAUNCH COST/EOTV" summed with EOTV cost per flight, "DOLLARS/KG OF PAYLOAD").
Where it comes from
PDF p.118 / 112, render read: "Array degradation is so rapid that one may expect no more than 3 trips. The system cost with 3 trips was hand calculated as about 80/kg. Increasing cover glass thickness allows substantially more trips (up to 10)." PDF p.129 / 123, render read: "If annealing cannot be developed, significantly more shielding (150 microns to 200 microns coverglass) should be used ... A ten-minute start delay leads to about a 10% cost penalty ... With present estimates of MPD performance, the ion option provides about 10% better cost performance." Figure 4.5-3 (PDF 124 / 118), render read: y-axis "TOTAL TRANSP COST/KG" from about 56 to 63, x-axis up trip time 120 to 240 days, Isp 5,000 to 9,000 s. Figure 4.5-8 (PDF 127 / 121), 200 dpi render: reference (anneal) Isp 8,000 180 days about 205 and chemical OTV Isp 470 1 day about 400 on the "hundreds of millions" axis.
Basis: USD 1979 per kg; per cent; trips
Related records
- Answers question
- QST-003 not published in this release
Cite this
energyaperture.com/c/clm-1032
CLM-1032, Energy Aperture, as of 1980-06.
Connected records
Other published records linked to this one. A list, not a judgement.