One of the nine satellites launched into geosynchronous orbit by NASA to track other spacecraft in low Earth orbits and relay their communications. The first of the second-generation satellites was TDRS-H launched in 2000, followed by TDRS-I and TDRS-J in 2002. These include the space shuttle, the Hubble Space Telescope, and the Landsat satellite series. Each TDRS weighs 2 270 kg and measures 17.4 m from the edges of the opposite solar panels. One TDRS was lost in the Challenger space shuttle disaster in 1986. The satellites are part of the Tracking and Data-Relay Satellite System (TDRSS) that includes ground stations. Each TDRS is controlled from the White Sands Test Facility in New Mexico by the Mission Operations and Data Systems Directorate of the Goddard Space Flight Center.
Subjects: Astronomy and Astrophysics.