Demosat

Sea Launch Demonstration Satellite

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General

Designation	25661 / 99014A
Launch date	28 Mar 1999
Country of origin	United States
Mission	Experimental
Perigee/Apogee
Inclination
Period
Launch vehicle	Zenit #31 (first Sea Launch)
Launch site	Sea Launch Odyssey

During pre-launch preparations, the Odyssey (located at 154°W and 0°N) was partially submerged for added stability. The rocket, with payload, then was withdrawn from its hangar on the platform, lifted into a vertical position, fuelled with kerosene and liquid oxygen (LOX), and launched. The fuelling and launch was completely automated and co-ordinated from the Sea Launch Commander.

The first two stages of the Zenit are built by Yuhznoe in the Ukraine. The third stage is a Blok DM-SL, built by Energiya/Kaliningrad and based on the Blok DM series used for Proton upper stages. Its first burn placed it in a 180 x 735 km x 1.2 deg parking orbit 13 min after launch, followed by a second burn 47 min after launch to deliver DemoSat to a 638 x 36064 km x 1.2 deg geostationary transfer orbit. A third DM-SL burn is then expected to lower the orbit for a quick reentry.

The rocket has a specific guidance computer (not the standard Zenit one)

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External resources

sat-index articles

Technical data

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Specifications

Prime contractor	Boeing Commercial Space
Platform	HS-702
Mass at launch	4500 kg
Mass in orbit
Dimension
Solar array
Stabilization
DC power
Design lifetime

Carries 130 sensors. Telemetry relayed in real time directly and by TDRS

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