Space Shuttle Communications and Telemetry - An Update

Abstract

During operational space flight, the communications and telemetry subsystem of the Space Shuttle orbiter uses S-band and Ku-band links to provide, in addition to tracking, reception of digitized voice, commands, and printed or diagrammatic data at a maximum rate of 216 kilobits per second (kbps). The subsystem also provides a transmission capability for digitized voice, telemetry, television, and data at a maximum rate of 50 megabits per second (mbps). S-band links may be established directly with a ground station and both S-band and Ku-band links may be routed through NASA's tracking and data relay satellite system (TDRSS). A simultaneous capability to communicate with other satellites or spacecraft, using a variety of formats and modulation techniques on more than 850 S-band channels, is provided. Ultrahigh frequency (UHF) is used for communication with extravehicular astronauts as well as for a backup subsystem for state vector update. Audio and television subsystems serve on-board needs as well as interfacing with the radio frequency (RF) equipment. During aerodynamic flight following entry, the S-band link can be supplemented or replaced by a UHF link that provides two-way simplex voice communication with air traffic control facilities.