||This article contains orbital elements but does not include an epoch, or date when those elements, which typically vary over time, were correct.|
TDRS-G before launch
|Mission duration||10 years (planned)
14+ years (achieved)
|Launch mass||3,180 kilograms (7,010 lb)|
|Start of mission|
|Launch date||13 July 1995, 13:41:55UTC|
|Rocket||Space Shuttle Discovery
STS-70 / IUS
|Launch site||Kennedy LC-39B|
|Longitude||150° West (1995-1996)
171° West (1996-2003)
150.5° West (2004—?)
|Perigee||35,767 kilometers (22,225 mi)|
|Apogee||35,803 kilometers (22,247 mi)|
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.
TDRS-7 is based on a custom satellite bus which was used for all seven first generation TDRS satellites. 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. 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. TDRS-G was deployed from Discovery around six hours after launch, and was raised to geosynchronous orbit by means of an Inertial Upper Stage.
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. 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 171° West where it was stored as an in-orbit spare, and subsequently entered service. In December 2003, it was relocated to 150.5° West. It arrived the next month, and was returned to storage as a reserve satellite.
- "UCS Satellite Database". Union of Concerned Scientists. 2009-07-01. Retrieved 2009-08-09.
- Krebs, Gunter. "TDRS 1, 2, 3, 4, 5, 6". Gunter's Space Page. Retrieved 2009-08-09.
- Krebs, Gunter. "TDRS 7". Gunter's Space Page. Retrieved 2009-08-09.
- McDowell, Jonathan. "Launch Log". Jonathan's Space Page. Retrieved 2009-08-09.
- McDowell, Jonathan. "Index". Geostationary Orbit Catalog. Jonathan's Space Page. Retrieved 2009-08-09.
- "The TDRS-J satellite". Spaceflight Now. 2002-12-01. Retrieved 2009-08-09.
- "TDRS 7". TSE. Retrieved 2009-08-09.