DemoSat was the dummy payload on the first Boeing Sea Launch mission. The Zenit-3SL booster rocket lifted off from the Odyssey floating platform on the equator at 154 degrees W longitude. The DemoSat payload was an instrumented dynamic model of an HS-702 satellite built by Boeing Commercial Space/Kent. The spacecraft is just a 4.5 tonne assembly of pipes and plates simulating a HS 702 spacecraft. Thirteen minutes after launch, the Blok DM-SL upper stage completed its first burn and entered a 180 km × 735 km x 1.2 degree parking orbit. A second burn 47 minutes after launch placed the satellite in a 638 × 36064 km × 1.2 degree geostationary transfer orbit. Three hours later, a third DM-SL burn lowered the stage's perigee so that it would re-enter quickly.
DemoSat was to feature as a last minute add-on the NATSweb (Naval Academy Tracking Satellite, Weber State) communication payload of the Naval Academy satellite program, but the addition wouuld have required a complete a total re-submission by Boeing for their entire Sea Launch System as the launcher's Export License (completed a year before) did not include an active payload. Therfor the NATSweb was not included in the launch.
| Nation: | USA |
|---|---|
| Type / Application: | Vehicle Evaluation |
| Operator: | Sea Launch |
| Contractors: | Boeing Commercial Space, Kent |
| Equipment: | ? |
| Configuration: | ? |
| Propulsion: | None |
| Power: | 2 deployable solar arrays, batteries |
| Lifetime: | |
| Mass: | 4500 kg |
| Orbit: | 638 km × 36064 km, 1.2° |
| Satellite | Date | LS | Launch Vehicle | Remarks | |
|---|---|---|---|---|---|
| DemoSat | 28.03.1999 | SL | Zenit-3SL (1) |