 TDRS-D being deployed fromDiscovery | |
| Mission type | Communication |
|---|---|
| Operator | NASA |
| COSPAR ID | 1989-021B |
| SATCATno. | 19883 |
| Mission duration | Planned: 10 years Final: 22 years, 9 months |
| Spacecraft properties | |
| Bus | TDRS |
| Manufacturer | TRW |
| Launch mass | 2,108 kg (4,647 lb)[1] |
| Dimensions | 17.3 × 14.2 m (57 × 47 ft) |
| Power | 1700 watts |
| Start of mission | |
| Launch date | 13 March 1989, 14:57:00 (1989-03-13UTC14:57) UTC |
| Rocket | Space Shuttle Discovery STS-29R /IUS |
| Launch site | Kennedy Space Center,LC-39B |
| Contractor | Rockwell International |
| End of mission | |
| Disposal | Retired to graveyard |
| Declared | December 2011 |
| Deactivated | May 2012 (2012-06) |
| Orbital parameters | |
| Reference system | Geocentric orbit |
| Regime | Geostationary orbit |
| Longitude | 41.0° West (1988–2005) 46.0° West (2005–2011) |
| Epoch | 14 March 1989[2] |
TDRS-4, known before launch asTDRS-D, is an Americancommunications satellite, of first generation, which was operated byNASA as part of theTracking and Data Relay Satellite System from 1989 until 2011. It was constructed byTRW, based on a customsatellite bus which was used for all seven of the first generation TDRS satellites.[3]
TDRS-D was launched aboardSpace Shuttle Discovery during theSTS-29 mission in 1989.Discovery launched fromLaunch Complex 39B at theKennedy Space Center at 14:57:00 UTC on 13 March 1989.[4] TDRS-D was deployed fromDiscovery a few hours after launch, and was raised togeostationary orbit by means of anInertial Upper Stage.[4]
The twin-stage solid-propellant Inertial Upper Stage made two burns. The first stage burn occurred shortly after deployment fromDiscovery, and placed the satellite into ageostationary transfer orbit (GTO). At 03:30 UTC on 14 March 1989, it reachedapogee, and the second stage fired, placing TDRS-D intogeostationary orbit.[5] At this point, it received its operational designation, TDRS-4. It was placed at alongitude 41.0° West of theGreenwich Meridian,[6][7] from where it provided communications services to spacecraft in Earth orbit, including theSpace Shuttle andInternational Space Station. In 2005, it was relocated to 46.0° West.[6]
TDRS-4 completed its planned mission in December 2011, and was subsequently removed to agraveyard orbit 350 kilometres (220 mi) aboveGEO orbit belt, perInternational Telecommunication Union (ITU) and United Nations (UN) recommendations.[8] In May 2012, NASA reported that the orbit-raising manoeuvre had been completed successfully, and the spacecraft had been retired.[9]
This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain.
