Value chain

In-orbit assembly and mass

Mass per unit of power, launch cost and launch rate, and building and servicing the structure in orbit.

This area is studied in more depth than the rest of the value chain. It spans 3 layers, with 151 published records between them.

Where each layer stands

Platform structure and control: where it stands

As of 2026-10-01

The platform is the satellite's frame, with the systems that point it and hold it in orbit. The 1978 US design, in its GaAlAs variant, planned 64 argon-ion thrusters to point the satellite, a thruster system never built at that scale (CLM-0332). The company Rockwell budgeted station-keeping, holding the satellite in its orbit position, at about 8 per cent of mass in argon over 30 years (CLM-1075). A 1980 study by NASA's Jet Propulsion Laboratory (JPL) modelled moving a 2,000 t payload between orbits with electric thrusters in 160 to 213 days, using projected thruster performance (CLM-0700). Stated first natural frequencies exist, but no source held here gives a computed first mode, the lowest natural vibration, or mode shapes for a 1 km antenna (CLM-0907).

Launch and orbital transport

As of 2026-10-01

Launch dominates cost in NASA's model, and no launch contract at the scale and rate these systems need has been signed at any of the prices quoted (CLM-0382). In that NASA model of two designs, launch is 71% and 77% of lifecycle cost. Of every 13 launches, 12 only carry fuel for payloads bound for geostationary orbit, the high orbit where a satellite stays over one point on Earth (CLM-0144). NASA's sensitivity run reports 62% total cost savings for its electric-propulsion variant, in which electric tugs move payloads between orbits instead of refuelling. This site's own calculation, built from NASA inputs, finds that the levelised cost, the lifetime cost per unit of electricity, falls 67%, to 0.2069 USD/kWh, after a 17.2% mass penalty for electric propulsion. That is still four to ten times the cost of the ground-based comparator (CLM-0601). The company Virtus Solis estimates USD 665/kg to low Earth orbit for a Starship that is not reused (CLM-0532). A January 1980 workshop of NASA, contractor and university staff judged the programme's timing unrealistic for space transport (CLM-1025).

In-space assembly and servicing

As of 2026-10-01

No cited source reports in-orbit assembly of solar power satellite hardware at full scale. A 2010 NASA Langley paper proposes a much smaller 450 kW-class vehicle, built from eight 50 kW-class modules, as a first step. It is a concept, not a demonstrated assembly (CLM-0343). The only measured human assembly rate in the sources held comes from Skylab 3, reported in a 1975 Raytheon study: an astronaut joined sunshade-pole sections at 6.2 minutes per operation (CLM-0965). The 1978 US design assumed that 555 or 715 people, for its two solar-cell options, could build a 5 GW satellite in six months (CLM-0963). That six months was a rule set at the start of the programme, not an engineering result (CLM-0982). This site's own calculation applies a manual rate of 6 to 12 kg per person-hour, calibrated to Skylab, to the whole satellite. Built at that rate, it would need 1,561 to 7,764 people. The published crews therefore imply about 2 to 14 times as much output per person as that rate, and the 1978 report does not say how (CLM-0973).

Layers in this area

The record count is every record tagged to that layer, not the number published. What the depth levels mean.