Encyclopedia Astronautica
TAOS


American military strategic defense satellite. One launch, 1994.03.13, USA 101. TAOS was a technology demonstration satellite whose purpose was to demonstrate autonomous space navigation systems to reduce satellite ground support needs.

Lowering the needs for ground support of future spacecraft would increase the survivability of satellites during wartime conditions and reduce satellite operations costs. TAOS also incorporated several new satellite bus components designed to improve reliability and maintainability of future spacecraft while reducing life-cycle costs. TAOS was the first mission flown under the USAF's STEP (Space Test Experiments Platform) program, and was designated STEP Mission 0. The satellite was controlled from Onizuka AFB, Calif. Satellite operations were interrupted on 19 July 1994 when an inertial measurement unit failed. During the following two month period, the satellite's solar panels could not be properly sun-pointed, resulting in a loss of satellite power. Vehicle control was regained following the development of a new satellite control system.

The spacecraft was 3-axis stabilized. Two solar arrays with 1-axis articulation provided power. A hydrazine propulsion system was used for orbit maintenance and to desaturate the momentum wheels. An S-Band communications link was made with SGLS RTS stations. A MIL-STD 1553B data bus was used for intra-satellite communications. Two MIL-STD 175OA computers were used for spacecraft control and payload operation.

The payload consisted of 10 experiments to investigate technologies applicable to autonomous space operations. The Microcosm Autonomous Navigation System (MANS) used two spinning sensors to provide Earth/Sun/Moon position measurements to determine satellite position and attitude. The system had a goal of 100 meters in position and 0.03 degrees in attitude. A six-channel Global Positioning System (GPS) receiver was used to calculate orbital position to within several meters. The 1553B data bus and MIL-STD 175OA computers were carried as technology demonstrations. The satellite also carried a radar sensor and two laser sensors.

AKA: Technology for Autonomous Operational Survivability.
Gross mass: 502 kg (1,106 lb).
Height: 1.73 m (5.67 ft).
First Launch: 1994.03.13.
Number: 1 .

More... - Chronology...


Associated Countries
See also
  • Taurus Pad-launched launch vehicle using Pegasus upper stages and Castor-120 first stage. More...

Associated Launch Vehicles
  • ARPA Taurus American all-solid orbital launch vehicle. Four stage version consisting of 1 x TU-904 + 1 x Orion 50 + 1 x Orion 50 + 1 x Orion 38 More...
  • Taurus American all-solid orbital launch vehicle. Pad-launched launch vehicle using Pegasus upper stages and Castor-120 first stage. First launch used slightly larger Peacekeeper ICBM first stage instead of Castor-120. Under a 2002 contract from Boeing, Orbital developed a three-stage version of Taurus to serve as the interceptor boost vehicles for the US government's missile intercept system. The firm portion of the company's contract, awarded in early 2002, was valued at $450 million and extended through 2007. More...

Associated Manufacturers and Agencies
  • USAF American agency overseeing development of rockets and spacecraft. United States Air Force, USA. More...
  • TRW American manufacturer of rockets, spacecraft, and rocket engines. TRW Corporation, Redondo Beach, CA, USA. More...
  • CTA American manufacturer of spacecraft. CTA, Inc. , Virginia, Virginia, Virginia, USA More...

Associated Programs
  • STEP Space Test Experiment Program; series of USAF technology test satellites. More...

Bibliography
  • McDowell, Jonathan, Jonathan's Space Home Page (launch records), Harvard University, 1997-present. Web Address when accessed: here.
  • JPL Mission and Spacecraft Library, Jet Propulsion Laboratory, 1997. Web Address when accessed: here.
  • McDowell, Jonathan, Launch Log, October 1998. Web Address when accessed: here.

Associated Launch Sites
  • Vandenberg Vandenberg Air Force Base is located on the Central Coast of California about 240 km northwest of Los Angeles. It is used for launches of unmanned government and commercial satellites into polar orbit and intercontinental ballistic missile test launches toward the Kwajalein Atoll. More...

TAOS Chronology


1994 March 13 - . 22:32 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg 576E. LV Family: Pegasus. Launch Vehicle: ARPA Taurus. LV Configuration: ARPA Taurus T1 1110.
  • USA 101 - . Payload: STEP-0 / STEP M0. Mass: 502 kg (1,106 lb). Nation: USA. Agency: USAF. Program: STEP. Class: Military. Type: Strategic defense satellite. Spacecraft: TAOS. USAF Sat Cat: 23030 . COSPAR: 1994-017A. Apogee: 561 km (348 mi). Perigee: 555 km (344 mi). Inclination: 105.0000 deg. Period: 95.80 min. Summary: Space Test Experiment Program; 10 satellite subsystem experiments. Space craft engaged in investigation of spaceflight techniques and technology (US Cat A). .

1994 July 19 - .
  • TAOS satellite IMU fails - . Nation: USA. Spacecraft: TAOS. TAOS was a technology demonstration satellite whose purpose is to demonstrate autonomous space navigation systems to reduce satellite ground support needs. Satellite operations were interrupted when an inertial measurement unit failed. During the following two month period, the satellite's solar panels could not be properly sun-pointed, resulting in a loss of satellite power. Vehicle control was regained following the development of a new satellite control system.

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