TDRS-7, known before launch as TDRS-G, is an American communications satellite, of first generation, 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

TDRS-G before launch at Kennedy Space Center
Mission type	Communication
Operator	NASA
COSPAR ID	1995-035B
SATCAT no.	23613
Mission duration	Planned: 10 years Elapsed: 26 years, 11 months, 20 days
Spacecraft properties
Bus	TDRS
Manufacturer	TRW
Launch mass	2108 kg [1]
Dimensions	17.3 metres long 14.2 metres wide
Power	1700 watts
Start of mission
Launch date	13 July 1995, 13:41:55 (1995-07-13UTC13:41:55) UTC
Rocket	Space Shuttle Discovery STS-70 / IUS
Launch site	Kennedy Space Center, LC-39B
Contractor	Rockwell International
Orbital parameters
Reference system	Geocentric orbit
Regime	Geostationary orbit
Longitude	150.0° West (1995–1996) 171.0° West (1996–2003) 150.5° West (2003–)
Epoch	14 July 1995 [2]

History

TDRS-7 is based on a custom satellite bus which was used for all seven first generation TDRS satellites.[3] Whilst similar to its predecessors, it differed from them slightly in that twelve G/H band (C band (IEEE)) transponders which had been included on the previous satellites were omitted.[4] It was the last communications satellite, other than amateur radio spacecraft, to be deployed by a Space Shuttle.

Launch

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 UTC on 13 July 1995.[5] TDRS-G was deployed from Discovery around six hours after launch, and was raised to geosynchronous orbit by means of an Inertial Upper Stage.[5]

Deployment

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 UTC on 14 July 1995 it reached apogee, and the second stage fired, placing TDRS-G into geostationary orbit.[6] At this point, it received its operational designation, TDRS-7. It was placed at a longitude 150.0° West of the Greenwich Meridian, where it underwent on-orbit testing. In May 1996, it was moved to 171.0° West where it was stored as an in-orbit spare, and subsequently entered service.[7] In December 2003, it was relocated to 150.5° West.[8] It arrived the next month, and was returned to storage as a reserve satellite.

See also

• List of TDRS satellites

References

На других языках

[es] TDRS-7