The U.S. Tracking and Data Relay Satellite System (TDRSS) is a network of American communications satellites and ground stations used by NASA for space communications. The system was designed to replace an existing network of ground stations that had supported all of NASA's crewed 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. Many Tracking and Data Relay Satellites were launched in the 1980s and 1990s with the Space Shuttle and made use of the Inertial Upper Stage, a two-stage solid rocket booster developed for the shuttle. Other TDRS were launched by Atlas IIa and Atlas V rockets.
Atlas V is an expendable launch system and the fifth major version in the Atlas launch vehicle family. It was originally designed by Lockheed Martin, now being operated by United Launch Alliance (ULA), a joint venture between Lockheed Martin and Boeing. It is used for DoD, NASA, and Commercial payloads. It is America's longest-serving active rocket. After 87 launches, in August 2021 ULA announced that Atlas V would be retired, and all 29 remaining launches had been sold. As of January 2024, 17 launches remain. Other future ULA launches will use the new Vulcan Centaur rocket.
A tracking and data relay satellite (TDRS) is a type of communications satellite that forms part of the Tracking and Data Relay Satellite System (TDRSS) used by NASA and other United States government agencies for communications to and from independent "User Platforms" such as satellites, balloons, aircraft, the International Space Station, and remote bases like the Amundsen-Scott South Pole Station. This system was designed to replace an existing worldwide network of ground stations that had supported all of NASA's crewed flight missions and uncrewed satellites in low-Earth orbits. The primary system design goal was to increase the amount of time that these spacecraft were in communication with the ground and improve the amount of data that could be transferred. These TDRSS satellites are all designed and built to be launched to and function in geosynchronous orbit, 35,786 km (22,236 mi) above the surface of the Earth.
United Launch Alliance, LLC, commonly referred to as ULA, is an American aerospace manufacturer, defense contractor and launch service provider that manufactures and operates rockets that launch spacecraft into Earth orbit and on trajectories to other bodies in the Solar System. ULA also designed and builds the Interim Cryogenic Propulsion Stage for the Space Launch System (SLS).
The Space Test Program (STP) is the primary provider of spaceflight for the United States Department of Defense (DoD) space science and technology community. STP is managed by a group within the Advanced Systems and Development Directorate, a directorate of the Space and Missile Systems Center of the United States Space Force. STP provides spaceflight via the International Space Station (ISS), piggybacks, secondary payloads and dedicated launch services.
Space Network (SN) is a NASA program that combines space and ground elements to support spacecraft communications in Earth vicinity. The SN Project Office at Goddard Space Flight Center (GSFC) manages the SN, which consists of:
TDRS-8, known before launch as TDRS-H, is an American communications satellite, of second generation, which is operated by NASA as part of the Tracking and Data Relay Satellite System. It was constructed by Boeing and is based on the BSS-601 satellite bus.
TDRS-B was an American communications satellite, of first generation, which was to have formed part of the Tracking and Data Relay Satellite System. It was destroyed in 1986 when the Space ShuttleChallenger disintegrated 73 seconds after launch.
TDRS-1, known before launch as TDRS-A, was an American communications satellite, operated by NASA as part of the Tracking and Data Relay Satellite System. It was constructed by TRW and launched by Space ShuttleChallenger on its maiden flight, STS-6.
TDRS-5, known before launch as TDRS-E, 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 is based on a custom satellite bus which was used for all seven first generation TDRS satellites.
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.
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.
TDRS-6, known before launch as TDRS-F, 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.
TDRS-7, known before launch as TDRS-G, 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 as a replacement for TDRS-B, which had been lost in the Challenger accident, and was the last first generation TDRS satellite to be launched.
TDRS-9, known before launch as TDRS-I, was an American communications satellite which was operated by NASA as part of the Tracking and Data Relay Satellite System. It was constructed by the Boeing Satellite Development Center, formerly Hughes Space and Communications, and was based on the BSS-601 satellite bus. It was the second Advanced TDRS, or second-generation Tracking and Data Relay Satellite, to be launched.
TDRS-10, known before launch as TDRS-J, is an American communications satellite which is operated by NASA as part of the Tracking and Data Relay Satellite System. It was constructed by the Boeing Satellite Development Center, formerly Hughes Space and Communications, and is based on the BSS-601 satellite bus. It was the third and final Advanced TDRS, or second-generation Tracking and Data Relay Satellite, to be launched.
TDRS-12, known before launch as TDRS-L, is an American communications satellite operated by NASA as part of the Tracking and Data Relay Satellite System. The twelfth Tracking and Data Relay Satellite, it is the second third-generation spacecraft to be launched, following TDRS-11 in 2013.
TDRS-13, known before launch as TDRS-M, is an American communications satellite operated by NASA as part of the Tracking and Data Relay Satellite System. The thirteenth Tracking and Data Relay Satellite, it is the third and final third-generation spacecraft to be launched, following the 2014 launch of TDRS-12.
