TDRS-4
TDRS-D being deployed from Discovery | |
| Mission type | Communication |
|---|---|
| Operator | NASA |
| COSPAR ID | 1989-021B |
| SATCAT no. | 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) |
| Dimensions | 17.3 × 14.2 m (57 × 47 ft) |
| Power | 1700 watts |
| Start of mission | |
| Launch date | 13 March 1989, 14:57:00 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 |
| Orbital parameters | |
| Reference system | Geocentric orbit |
| Regime | Geostationary orbit |
| Longitude | 41.0° West (1988–2005) 46.0° West (2005–2011) |
| Epoch | 14 March 1989 |
TDRS-4, known before launch as TDRS-D, is an American communications satellite, of first generation, which was operated by NASA as part of the Tracking and Data Relay Satellite System from 1989 until 2011. It was constructed by TRW, based on a custom satellite bus which was used for all seven of the first generation TDRS satellites.