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TDRS-C aboard Discovery
Mission typeCommunication
COSPAR ID1988-091B
SATCAT no.19548[1]
Mission duration10 years (planned)
20+ years (achieved)
Spacecraft properties
Launch mass3,180 kilograms (7,010 lb)[2]
Start of mission
Launch dateSeptember 29, 1988, 15:37:00 (1988-09-29UTC15:37Z) UTC
RocketSpace Shuttle Discovery
STS-26 / IUS
Launch siteKennedy LC-39B
Orbital parameters
Reference systemGeocentric
Longitude151° West (1988)
171° West (1988-1990)
174° West (1990-1991)
62° West (1991-1994)
171° West (1994-1995)
85° East (1995—2009)
49° West (2009-)
Perigee35,693 kilometers (22,179 mi)
Apogee35,878 kilometers (22,294 mi)
Inclination0° (BOL)
11.53 degrees (Current)
Period1,434.8 minutes
Epoch29 September 1988, 11:37:00 UTC[3]

TDRS-3 , known before launch as TDRS-C, 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, and is based on a custom satellite bus which was used for all seven first generation TDRS satellites.[4]


The launch of STS-26, carrying TDRS-C

The TDRS-C satellite was launched aboard Space Shuttle Discovery during the STS-26 mission in 1988; the first Shuttle flight since the Challenger accident 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 GMT on September 29, 1988.[5] TDRS-C was deployed from Discovery around six hours after launch, and was raised to geostationary orbit by means of an Inertial Upper Stage.[5]


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 on September 30, 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.[6] It was briefly placed at a longitude 151° West of the Greenwich Meridian, before being moved to 171° 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° West, and again in 1991 to 62° West. In 1994 it returned to 171° West.[7][8] In June 1995, it was moved to 85° East, from where it was used primarily for communications with spacecraft such as the Compton Gamma Ray Observatory and the Hubble Space Telescope.[7][9] In October 2009, as NASA began decommissioning TDRS-1, TDRS-3 was moved to 49° West,[10] where it remains in storage as of 2014.[11]


  1. ^ McDowell, Jonathan. "SATCAT". Jonathan's Space Pages. Retrieved 18 March 2014.
  2. ^ "UCS Satellite Database". Union of Concerned Scientists. 2009-07-01. Retrieved 2009-08-08.
  3. ^ "NASA - NSSDCA - Spacecraft - Trajectory Details". Retrieved 2018-05-02.
  4. ^ Krebs, Gunter. "TDRS 1, 2, 3, 4, 5, 6". Gunter's Space Page. Retrieved 2009-08-08.
  5. ^ a b McDowell, Jonathan. "Launch Log". Jonathan's Space Page. Retrieved 2009-08-08.
  6. ^ "Designation". NASA'S Tracking and Data Relay Satellite. NASA. December 1992. Archived from the original on 2009-08-03.
  7. ^ a b "TDRS 3". TSE. Retrieved 2009-08-08.
  8. ^ McDowell, Jonathan. "Index". Geostationary Orbit Catalog. Jonathan's Space Page. Retrieved 2009-08-08.
  9. ^ "The TDRS-J satellite". Spaceflight Now. 2002-12-01. Retrieved 2009-08-08.
  10. ^ Clark, Stephen (13 October 2009). "NASA retires 'queen' of tracking satellite fleet". Spaceflight Now. Retrieved 18 March 2014.
  11. ^ "Tracking and Data Relay Satellite (TDRS) Fleet". NASA. 11 February 2014. Retrieved 18 March 2014.