TDRS-3

TDRS-3, known before launch as TDRS-C, 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, and is based on a custom satellite bus which was used for all seven first generation TDRS satellites.

Launch


The TDRS-C satellite was launched aboard during the STS-26 mission in 1988; the first Shuttle flight since the Challenger disaster which had resulted in the loss of the previous TDRS satellite, TDRS-B. Discovery launched from Launch Complex 39B at the Kennedy Space Center at 15:37:00 UTC on 29 September 1988. TDRS-C was deployed from Discovery around six hours after launch, and was raised to geostationary orbit by means of an Inertial Upper Stage.

Deployment
The two-stage solid-propellent Inertial Upper Stage made two burns. The first stage burn occurred shortly after deployment from Discovery, and placed the satellite into a geosynchronous transfer orbit. At 04:30 UTC on 30 September 1988, it reached apogee, and the second stage fired, placing TDRS-C into geosynchronous orbit. At this point it received its operational designation. Although the TDRS-2 designation had not been assigned, TDRS-C was given the designation TDRS-3 as NASA did not want to reuse the designation which had been intended for the STS-51-L payload. It was briefly placed at a longitude 151° West of the Greenwich Meridian, before being moved to 171.0° West before the end of 1988, from where it provided communications services to spacecraft in Earth orbit, including Space Shuttles. In 1990, it was relocated to 174.0° West, and again in 1991 to 62.0° West. In 1994, it returned to 171.0° West. In June 1995, it was moved to 85.0° East, from where it was used primarily for communications with spacecraft such as the Compton Gamma Ray Observatory and the Hubble Space Telescope. In October 2009, as NASA began decommissioning TDRS-1, TDRS-3 was moved to 49.0° West, where it remains in storage as of 2020.