SPACE SHUTTLE ORBITER TELEMETRY/COMMAND DESIGN ASPECTS AND FLIGHT TEST RESULTS

Abstract

During the first flight of Columbia (STS-1), the Instrumentation, Communications, and Tracking Subsystems (I-C&TSS) of the Space Shuttle orbiter used S-band links to provide (in addition to tracking) reception of digitized voice, commands, and printed or diagrammatic data at a maximum rate of 72 kilobits per second (kbps). The subsystem also provided a transmission capability for digitized voice, telemetry, television, and real-time and recorded data. Communication was via S-band directly to the ground stations; ultrahigh frequency (UHF) voice was used for communication with the landing site and some ground stations and for providing a backup link for state vector update. Audio and television subsystems served on-board needs and interfaced with the radio frequency (RF) equipment. Provisions were provided to record on-board data for post-flight playback. During aerodynamic flight following entry, the S-band link was used to supplement the UHF link that provides two-way simplex voice communication with air traffic control facilities. The I-C&T subsystem for STS-1 operated with almost textbook performance; exceptions were a dedicated signal conditioner redundancy failure, failure of the development flight instrumentation PCM recorder, and some measurement sensor failures.