Encyclopedia Astronautica
TDRS



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TDRS
Credit: Lockheed-Martin
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STS-6
Deployment of the TDRS by STS-6 Challenger
Credit: NASA
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STS-6
TDRS satellite over African Rift Valley, Kenya, Africa
Credit: NASA
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STS-26
STS-26 Discovery, Orbiter Vehicle (OV) 103, IUS / TDRS-C deployment
Credit: NASA
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STS-26
STS-26 Discovery, Orbiter Vehicle (OV) 103, IUS / TDRS-C deployment
Credit: NASA
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STS-26
STS-26 Discovery, Orbiter Vehicle (OV) 103, IUS / TDRS-C deployment
Credit: NASA
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STS-26
STS-26 Discovery, Orbiter Vehicle (OV) 103, IUS / TDRS-C deployment
Credit: NASA
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STS-26
STS-26 Discovery, Orbiter Vehicle (OV) 103, IUS / TDRS-C deployment
Credit: NASA
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STS-29
STS-29 IUS with TDRS-D drifts above Earth's surface during post deployment
Credit: NASA
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STS-29
STS-29 IUS with TDRS-D after deployment from Discovery, OV-103
Credit: NASA
American military communications satellite. 7 launches, 1983.04.04 (TDRS 1) to 1995.07.13 (TDRS 7). Satellite communications network, for use by Shuttle and US military satellites.

When first launched, the TDRS satellites were the largest, most sophisticated communications satellites ever built. The seventh vehicle in the series was ordered as a replacement when TDRS-2 was lost in the Challenger accident.

The hexagonal spacecraft and payload modules were 3-axis stabilized. The zero momentum biased control system used reaction wheels and Earth sensors. Two solar arrays provided 2 kW BOL (1.7 kW EOL). These arrays had an area of ~ 29 sq. m and were articulated about one axis. Two 40 Ahr NiCd batteries provided power during eclipse. A hydrazine propulsion system with 24 4.45 N thrusters was used for orbit circularization and orbit maintenance. Spacecraft telemetry and commanding were performed via a Ku-band communications system, with emergency backup provided by an S-band system.

Payload included:

  • Two Single Access (SA) antennas - each antenna was a 4.9 m diameter molybdenum wire mesh antenna that could be used for Ku-band and S-band links. Each antenna was steerable in 2-axes and communicates with one target spacecraft at a time.
  • One Multiple Access (MA) S-band antenna array - an electronically steerable phased array consisting of 30 fixed helix antennas. The MA array could receive data from up to 20 user satellites simultaneously, although it could transmit to only one satellite at a time. Twelve of the helices could transmit and receive, with the remainder only able to receive.
  • One Space to Ground Link antenna (SGL) - a 2 meter parabolic antenna operating at Ku-band that provided the communications link between the satellite and the ground. All customer data were sent through this dish, as were all regular TDRS command and telemetry signals. The antenna was gimbaled on two axes.
  • One S-band omni antenna - a conical log spiral antenna used during the satellite's deployment phase and as a backup the event of a spacecraft emergency. This antenna did not support customer links.
  • One small Ku-band and one small C-band antenna were also carried, designed to support communications with Westar satellites, but were no longer used.
  • Transponders:
    • Four (plus 2 spare) 25W Ku-band TWTAs for LP (linearly polarized) zone coverage.
    • Two (plus 2 spare) 1.5W Ku-band TWTAs for CP (circularly polarized) spot coverage.
    • Two (plus 4 spare) 25W Ku-band TWTAs for LP zone coverage.
    • Two (plus 2 spare) 1.5W Ku-band TWTAs for CP spot coverage
    • 12 5W TWTAs for LP C-Band up/downtown (plus 2 spare)
    • 26W S-band SSPAs (used for intersatellite links)
    • Eight (plus 4 spare) 3.5W S-band SSPAs (used for intersatellite links)

Hughes received a contract on 23 February 1995 for TDRS replacement - $ 481.6 million for 3 HS-601 spacecraft with added Ka band. Last launch was originally set for 2002. Program total cost to 1997 was $ 3.3 billion over 10 years.

AKA: Tracking and Data Relay Satellite.
Gross mass: 2,240 kg (4,930 lb).
Span: 17.40 m (57.00 ft).
First Launch: 1983.04.04.
Last Launch: 1995.07.13.
Number: 7 .

More... - Chronology...


Associated Countries
See also
  • Shuttle The manned reusable space system which was designed to slash the cost of space transport and replace all expendable launch vehicles. It did neither, but did keep NASA in the manned space flight business for 30 years. More...

Associated Launch Vehicles
  • Shuttle American winged orbital launch vehicle. The manned reusable space system which was designed to slash the cost of space transport and replace all expendable launch vehicles. It did neither, but did keep NASA in the manned space flight business for 30 years. Redesign of the shuttle with reliability in mind after the Challenger disaster reduced maximum payload to low earth orbit from 27,850 kg to 24,400 kg. More...

Associated Manufacturers and Agencies
  • NASA American agency overseeing development of rockets and spacecraft. National Aeronautics and Space Administration, USA, USA. More...
  • Contel American agency overseeing development of spacecraft. Contel, USA. More...
  • TRW American manufacturer of rockets, spacecraft, and rocket engines. TRW Corporation, Redondo Beach, CA, USA. More...

Associated Programs
  • STS The Space Transportation System (Space Shuttle) was conceived originally as a completely reusable system that would provide cheap, routine access to space and replace all American and civilian military launch vehicles. Crippled by technological overreach, political compromise, and budget limitations, it instead ended up costing more than the expendable rockets it was to have replaced. STS sucked the money out of all other NASA projects for half a century. The military abandoned its use after the Challenger shuttle explosion in the 1980's. 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.
  • NASA Report, TDRS-I Press Kit, Web Address when accessed: here.
  • NASA Report, TDRSS Information Package, Web Address when accessed: here.
  • NASA Report, TDRS H,I, J Fact Sheet, Web Address when accessed: here.

Associated Launch Sites
  • Cape Canaveral America's largest launch center, used for all manned launches. Today only six of the 40 launch complexes built here remain in use. Located at or near Cape Canaveral are the Kennedy Space Center on Merritt Island, used by NASA for Saturn V and Space Shuttle launches; Patrick AFB on Cape Canaveral itself, operated the US Department of Defense and handling most other launches; the commercial Spaceport Florida; the air-launched launch vehicle and missile Drop Zone off Mayport, Florida, located at 29.00 N 79.00 W, and an offshore submarine-launched ballistic missile launch area. All of these take advantage of the extensive down-range tracking facilities that once extended from the Cape, through the Caribbean, South Atlantic, and to South Africa and the Indian Ocean. More...
  • Cape Canaveral LC39B Shuttle, Saturn V, Saturn I launch complex. LC39A and LC39B, part of the Kennedy Space Center, were built on Merritt Island (north/northwest of the Cape) to support the Saturn V/Apollo lunar landing program in 1963-1966. The sites were modified in the last half of the 1970s to support the manned Space Shuttle program. More...
  • Cape Canaveral LC39A Shuttle, Saturn V launch complex. LC39A and LC39B, part of the Kennedy Space Center, were built on Merritt Island (north/northwest of the Cape) to support the Saturn V/Apollo lunar landing program. The sites were modified in the last half of the 1970s to support the manned Space Shuttle program. Construction began in December 1963. Complex 39A was completed on 4 October 1965. Complex 39A supported two unmanned and nine manned Saturn V/Apollo missions between 9 November 1967 and 8 December 1972. The site also supported the launch of the Skylab space station on 14 May 1973. Both complexes were modified to support Space Shuttle missions later on. Complex 39A supported the first Space Shuttle launch on 12 April 1981. More...

TDRS Chronology


1983 April 4 - . 18:30 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC39A. LV Family: Shuttle. Launch Vehicle: Shuttle. LV Configuration: Space Shuttle STS-6.
  • TDRS 1 - . Payload: TDRS A. Mass: 2,268 kg (5,000 lb). Nation: USA. Agency: NASA Greenbelt. Program: STS. Class: Communications. Type: Civilian communications satellite. Spacecraft: TDRS. USAF Sat Cat: 13969 . COSPAR: 1983-026B. Apogee: 35,976 km (22,354 mi). Perigee: 35,835 km (22,266 mi). Inclination: 7.4000 deg. Period: 1,442.20 min. Element of satellite communications network, deployed from STS-6 5 April 1983. Spacecraft engaged in practical applications and uses of space technology such as weather or communication (US Cat C). Positioned in geosynchronous orbit at 67 deg W in 1983; 41 deg W in 1983-1989; 79 deg W in 1989-1990; 170 deg W in 1990-1993; 85 deg E in 1994-1995; 49 deg W in 1996-on. As of 5 September 2001 located at 49.36 deg W drifting at 0.010 deg E per day. As of 2007 Mar 9 located at 48.98W drifting at 0.029W degrees per day.

1986 January 28 - . 16:38 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC39B. LV Family: Shuttle. Launch Vehicle: Shuttle. LV Configuration: Space Shuttle 51-L. FAILURE: Failure.
  • TDRS B - . Payload: TDRS B. Nation: USA. Agency: NASA. Program: STS. Class: Communications. Type: Civilian communications satellite. Spacecraft: TDRS. COSPAR: F860128C. Apogee: 15 km (9 mi).

1988 September 29 - . 15:37 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC39B. LV Family: Shuttle. Launch Vehicle: Shuttle. LV Configuration: Space Shuttle STS-26R.
  • TDRS 3 - . Payload: TDRS C. Mass: 2,200 kg (4,800 lb). Nation: USA. Agency: NASA Greenbelt. Program: STS. Class: Communications. Type: Civilian communications satellite. Spacecraft: TDRS. USAF Sat Cat: 19548 . COSPAR: 1988-091B. Apogee: 35,796 km (22,242 mi). Perigee: 35,774 km (22,228 mi). Inclination: 0.5000 deg. Period: 1,436.10 min. NASA communications; 171 deg W; deployed from STS-26 . Spacecraft engaged in practical applications and uses of space technology such as weather or communication (US Cat C). Positioned in geosynchronous orbit at 151 deg W in 1988; 171 deg W in 1989-1990; 174 deg W in 1990-1991; 62 deg W in 1991-1994;171 deg W in 1994-1995; 85 deg E in 1995-1999 As of 26 August 2001 located at 85.17 deg E drifting at 0.007 deg E per day. As of 2007 Mar 10 located at 84.98E drifting at 0.004W degrees per day.

1989 March 13 - . 14:57 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC39B. LV Family: Shuttle. Launch Vehicle: Shuttle. LV Configuration: Space Shuttle STS-29R.
  • TDRS 4 - . Payload: TDRS D. Mass: 2,120 kg (4,670 lb). Nation: USA. Agency: NASA Greenbelt. Program: STS. Class: Communications. Type: Civilian communications satellite. Spacecraft: TDRS. USAF Sat Cat: 19883 . COSPAR: 1989-021B. Apogee: 35,803 km (22,246 mi). Perigee: 35,773 km (22,228 mi). Inclination: 4.6000 deg. Period: 1,436.20 min. Deployed from STS 29 13 March 1989; NASA communications; 41 deg W. Spacecraft engaged in practical applications and uses of space technology such as weather or communication (US Cat C). Positioned in geosynchronous orbit at 41 deg W in 1989-1999 As of 5 September 2001 located at 41.04 deg W drifting at 0.010 deg W per day. As of 2007 Mar 10 located at 45.81W drifting at 0.008W degrees per day.

1991 August 2 - . 15:02 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC39A. LV Family: Shuttle. Launch Vehicle: Shuttle. LV Configuration: Space Shuttle STS-43.
  • TDRS 5 - . Payload: TDRS E. Mass: 2,200 kg (4,800 lb). Nation: USA. Agency: NASA Greenbelt. Program: STS. Class: Communications. Type: Civilian communications satellite. Spacecraft: TDRS. USAF Sat Cat: 21639 . COSPAR: 1991-054B. Apogee: 35,790 km (22,230 mi). Perigee: 35,783 km (22,234 mi). Inclination: 0.0000 deg. Period: 1,436.10 min. NASA communications; 174 deg W; deployed from STS-43 8/2/91. Spacecraft engaged in research and exploration of the upper atmosphere or outer space (US Cat B). Positioned in geosynchronous orbit at 174 deg W in 1991-1999 As of 1 September 2001 located at 174.28 deg W drifting at 0.011 deg E per day. As of 2007 Mar 10 located at 171.61W drifting at 0.006W degrees per day.

1993 January 13 - . 13:59 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC39B. LV Family: Shuttle. Launch Vehicle: Shuttle. LV Configuration: Space Shuttle STS-54.
  • TDRS 6 - . Payload: TDRS F. Mass: 2,530 kg (5,570 lb). Nation: USA. Agency: NASA Greenbelt. Program: STS. Class: Communications. Type: Civilian communications satellite. Spacecraft: TDRS. USAF Sat Cat: 22314 . COSPAR: 1993-003B. Apogee: 35,792 km (22,240 mi). Perigee: 35,779 km (22,231 mi). Inclination: 0.7000 deg. Period: 1,436.10 min. NASA communications; deployed from STS-54 1/13/93. Spacecraft engaged in research and exploration of the upper atmosphere or outer space (US Cat B). Positioned in geosynchronous orbit at 150 deg W in 1993; 138 deg W in 1993; 46 deg W in 1994-1999 As of 5 September 2001 located at 46.99 deg W drifting at 0.017 deg W per day. As of 2007 Mar 8 located at 173.51W drifting at 0.006E degrees per day.

1995 July 13 - . 13:41 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC39B. Launch Platform: MLP2. LV Family: Shuttle. Launch Vehicle: Shuttle. LV Configuration: Space Shuttle STS-70.
  • TDRS 7 - . Payload: TDRS G. Mass: 2,120 kg (4,670 lb). Nation: USA. Agency: NASA Greenbelt. Program: STS. Class: Communications. Type: Civilian communications satellite. Spacecraft: TDRS. USAF Sat Cat: 23613 . COSPAR: 1995-035B. Apogee: 35,797 km (22,243 mi). Perigee: 35,776 km (22,230 mi). Inclination: 5.3000 deg. Period: 1,436.10 min. NASA communications; deployed from STS-70 on 7/13/95. Stationed at 149.8 deg W. Positioned in geosynchronous orbit at 150 deg W in 1995-1996; 171 deg W in 1996-1999 As of 3 September 2001 located at 171.48 deg W drifting at 0.017 deg W per day. As of 2007 Mar 11 located at 150.85W drifting at 0.002E degrees per day.

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