A Tracking and Data Relay Satellite (TDRS) is one of a network of communications satellites of the Tracking and Data Relay Satellite System (TDRSS) used by NASA and other United States government agencies for communication to satellites or the International Space Station. The system was designed to replace an existing network of ground stations that had supported all of NASA's manned flight missions. The prime design goal was to increase the time spacecraft were in communication with the ground and improve the amount of data that could be transferred.
The initial seven satellites were built by TRW; later, three versions have been put together by Boeing's Satellite Systems division. 10 satellites have been launched. 9 satellites are still in service. All were managed by NASA Goddard Space Flight Center. The contract for TDRS versions L & K was awarded to Boeing on December 20, 2007.
The second was lost on the Challenger's 10th mission when it was destroyed with the Challenger shortly after liftoff on STS-51-L in 1986. The next five were launched on other shuttles. The three Boeing-built successors were launched on Atlas rockets in 2000 and 2002. A NASA Press Release summarized the capabilities of the system as a whole:
"Working solo, TDRS-1 provided more communication coverage, in support of the September 1983 Shuttle mission, than the entire network of NASA tracking stations had provided in all previous Shuttle missions."
|Name||Launch date||Mission name||NSSDC ID No.||Notes|
|TDRS A||April 4, 1983||STS-6||1983-026B||also TDRS 1|
|TDRS B||January 28, 1986||STS-51-L||TDRSS-B||destroyed in the Challenger disaster, also TDRS 2|
|TDRS C||Sept. 29, 1988||STS-26||1988-091B||also TDRS 3|
|TDRS D||March 13, 1989||STS-29||1989-021B||also TDRS 4|
|TDRS E||August 2, 1991||STS-43||1991-054B||also TDRS 5|
|TDRS F||January 13, 1993||STS-54||1993-003B||also TDRS 6|
|TDRS G||July 13, 1995||STS-70||1995-003B||replacement for the lost TDRS B, also TDRS 7|
|TDRS H||June 30, 2000||Atlas IIa||2000-034A||First of the second generation of Boeing TDRS, also TDRS 8|
|TDRS I||March 8, 2002||Atlas IIa||2002-011A||also TDRS 9|
|TDRS J||December 4, 2002||Atlas IIa||2002-055A||also TDRS 10|