TDRS-G before launch |
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Operator | NASA |
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Major contractors | TRW USA (LSP) |
Mission type | Communication |
Launch date | 13 July 1995 13:41:55 GMT |
Carrier rocket | Space Shuttle Discovery STS-70 / IUS |
Launch site | Kennedy LC-39B |
Mission duration | 10 years (planned) 14+ years (achieved) |
Mass | 3,180 kilograms (7,000 lb)[1] |
Orbital elements | |
Regime | Geostationary |
Inclination | 10.6ยฐ |
Apoapsis | 35,803 kilometres (22,247 mi) |
Periapsis | 35,767 kilometres (22,225 mi) |
Longitude | 150ยฐ West (1995-1996) 171ยฐ West (1996-2003) 150.5ยฐ West (2004โ) |
TDRS-7, known before launch as TDRS-G, is an American communications satellite which is operated by NASA as part of the Tracking and Data Relay Satellite System. It was constructed by TRW as a replacement for TDRS-B, which had been lost in the Challenger accident, and was the last first-generation TDRS satellite to be launched.
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TDRS-7 is based on a custom satellite bus which was used for all seven first generation TDRS satellites.[2] Whilst similar to its predecessors, it differed from them slightly in that twelve G/H band (IEEE C band) transponders which had been included on the previous satellites were omitted.[3] It was the last communications satellite, other than amateur radio spacecraft, to be deployed by a Space Shuttle.
The TDRS-G satellite was deployed from Space Shuttle Discovery during the STS-70 mission in 1995. Discovery was launched from Kennedy Space Center Launch Complex 39B at 13:41:55 GMT on 13 July 1995.[4] TDRS-G was deployed from Discovery around six hours after launch, and was raised to geosynchronous orbit by means of an Inertial Upper Stage.[4]
The twin-stage solid-propellent Inertial Upper Stage made two burns. The first stage burn occurred around an hour after deployment from Discovery, and placed the satellite into a geosynchronous transfer orbit. At 02:30 on 14 July it reached apogee, and the second stage fired, placing TDRS-G into geostationary orbit.[5] At this point it received its operational designation, TDRS-7. It was placed at a longitude 150 degrees West of the Greenwich Meridian, where it underwent on-orbit testing.
In May 1996 it was moved to 171ยฐ West where it was stored as an in-orbit spare, and subsequently entered service.[6] In December 2003, it was relocated to 150.5ยฐ West.[7] It arrived the next month, and was returned to storage as a reserve satellite.
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