Tracking and data relay satellite

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.

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.

This expenditure of fuel reduced its capability to remain in a geostationary orbit; by late 1997 the orbit had changed to the point that the satellite was able to see the South Pole, and an uplink/downlink station was installed at Amundsen–Scott South Pole Station in January 1998;[8] TDRS-1 was an important communication uplink for Antarctic research until 2009.

A NASA Press Release[9] 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.

[5] The two TDRSS satellite ground terminals are located at NASA White Sands Complex, which is in the Las Cruces area.

All radioed commands and received telemetry that go to and from the tracking and data relay satellites go by way of these terminals at the White Sands Complex.

However, some years later, due to increased user demand NASA ordered the design and construction of a second ground terminal system about 5 kilometres (3.1 mi) away.