TDRSS
Tracking and Data Relay Satellite System

This NASA communication relay system which provides links between low earth orbiting spacecraft and the ground. The system provides extended view times for LEO satellite communications links, and is capable of transmitting to and receiving data from any LEO spacecraft over at least 85% of its orbit. The TDRSS space segment currently consists of six first generation Tracking and Data Relay Satellites (TDRS) located in geosynchronous orbit, of which 3 are available for operational support at any given time. The remaining vehicles provide backup in the event of the failure of an operational spacecraft and, in some specialized cases, resources for target of opportunity activities. The TDRSS ground segment, the White Sands Ground Terminal located near Las Cruces, New Mexico, controls the TDRS satellites and receives/transmits data from/to customers' LEO satellites through the TDRS satellites. The ground system, originally controlled and operated by the Contel Corporation, is now owned by NASA and operated by Allied Signal Technical Services Corp. In addition to its support of NASA communications links, the satellites also carry C- and Ku-band transponders for lease to private companies for commercial use. NASA missions supported by the system include the Hubble Telescope, the Space Shuttle, GRO, Landsat, TOPEX, and EUVE and support is planned for the International Space Station. In February 1995, Hughes was awarded a $486.1M contract for 3 second generation TDRS spacecraft.

Related QuickLook Pages:

• ATDRS
• TDRSS