Encyclopedia Astronautica
GPS Block 1



gpsblok1.jpg
GPS Block 1
Credit: USAF
American navigation satellite. 11 launches, 1978.02.22 (Navstar 1) to 1985.10.09 (USA 10). GPS Block 1 prototype satellites formed the GPS Demonstration system and were followed by the Block 2 operational system.

The spacecraft was 3-axis stabilized, nadir pointing using reaction wheels. Dual solar arrays supplied over 400 watts (EOL) and charged NiCd batteries. S-Band (SGLS) communications were used for control and telemetry. A UHF channel provided cross-links between spacecraft. A hydrazine propulsion system was used for orbital correction. The payload included two L-Band navigation signals at 1575.42 MHz (L1) and 1227.60 MHz (L2)

Block I satellites cost $ 20 million each. In 1974 Rockwell was awarded a contract to build 8 satellites. A 1978 contract amendment added 4 additional satellites. This was subsequently modified in 1981 for the twelfth satellite to be produced as the first GPS Block 2 qualification model.

Electric System: 0.40 average kW.

AKA: Global Positioning System; Navstar.
Gross mass: 759 kg (1,673 lb).
Span: 5.30 m (17.30 ft).
First Launch: 1978.02.22.
Last Launch: 1985.10.09.
Number: 11 .

More... - Chronology...


Associated Countries
Associated Engines
  • Star 27 Thiokol solid rocket engine. 27 kN. Apogee motor used on CTS, GMS, BS, GPS, GOES satellites. In Production. Isp=288s. More...

See also
  • Atlas The Atlas rocket, originally developed as America's first ICBM, was the basis for most early American space exploration and was that country's most successful medium-lift commercial launch vehicle. It launched America's first astronaut into orbit; the first generations of spy satellites; the first lunar orbiters and landers; the first probes to Venus, Mars, Mercury, Jupiter, and Saturn; and was America's most successful commercial launcher of communications satellites. Its innovative stage-and-a-half and 'balloon tank' design provided the best dry-mass fraction of any launch vehicle ever built. It was retired in 2004 after 576 launches in a 47-year career. More...

Associated Launch Vehicles
  • Atlas The Atlas rocket, originally developed as America's first ICBM, was the basis for most early American space exploration and was that country's most successful medium-lift commercial launch vehicle. It launched America's first astronaut into orbit; the first generations of spy satellites; the first lunar orbiters and landers; the first probes to Venus, Mars, Mercury, Jupiter, and Saturn; and was America's most successful commercial launcher of communications satellites. Its innovative stage-and-a-half and 'balloon tank' design provided the best dry-mass fraction of any launch vehicle ever built. It was retired in 2004 after 576 launches in a 47-year career. More...
  • Atlas E American intercontinental ballistic missile. Initial fully operational version of Atlas ICBM. Differed in guidance system from Atlas F. Deployed as missiles from 1960 to 1966. After retirement, the ICBM's were refurbished and used over twenty years as space launch vehicles. More...
  • Atlas F American intercontinental ballistic missile. Final operational version of Atlas ICBM. Differed in guidance systems. Deployed as missiles from 1961 to 1966. After retirement, the ICBM's were refurbished and used for over thirty years as space launch vehicles. More...
  • Atlas F/SVS American orbital launch vehicle. Atlas F + 1 x Star 37E + 1 x Star 37E upper stages. More...
  • Atlas E/SVS American orbital launch vehicle. Atlas E + 1 x Star 37E + 1 x Star 37E upper stages. More...
  • Atlas E/SGS-2 American orbital launch vehicle. Atlas E + 1 x Star 48 + 1 x Star 48 upper stages. More...

Associated Manufacturers and Agencies
  • USAF American agency overseeing development of rockets and spacecraft. United States Air Force, USA. More...
  • North American American manufacturer of rockets, spacecraft, and rocket engines. North American, Palmdale, El Segundo. Downey, CA, USA More...

Associated Programs
  • Navstar The Navstar GPS (Global Positioning System) program was a joint service effort directed by the United States Department of Defence. Navstar GPS is a space-based radio-positioning system nominally consisting of a 24-satellite constellation that provides navigation and timing information to military and civilian users worldwide. In addition to the satellites, the system consists of a worldwide satellite control network and GPS receiver units that acquire the satellite's signals and translate them into position information. Originally envisioned as primarily a military system, GPS was found to have a wide variety of civilian applications, many of them never conceived by the original system's designers. More...

Bibliography
  • McDowell, Jonathan, Jonathan's Space Home Page (launch records), Harvard University, 1997-present. Web Address when accessed: here.
  • Krebs, Gunter, Gunter's Space Page, University of Frankfurt, 1996. Web Address when accessed: here.
  • JPL Mission and Spacecraft Library, Jet Propulsion Laboratory, 1997. Web Address when accessed: here.
  • Lockheed Martin Coporation, Atlas Family Fact Sheets, September 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...
  • Vandenberg SLC3W Delta, Atlas launch complex. First designated LC1-1 and used to launch Atlas Agena B with Samos payloads. After Samos cancellation, rebuilt in 1963 to support launch of KH-4 Corona spysats atop Thor-Agena. Refurbished in 1973 to accomodate surplus Atlas ICBM's in space launch role. More...
  • Vandenberg SLC3E Atlas V, Atlas launch complex. Atlas test facility, originally designated PALC1-2, then LC1-2, and finally upgraded to a Space Launch Facility in 1966. More...

GPS Block 1 Chronology


1978 February 22 - . 23:44 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC3E. LV Family: Atlas. Launch Vehicle: Atlas F/SVS. LV Configuration: Atlas F/SVS 64F.
  • Navstar 1 - . Payload: GPS SVN 1 / OPS 5111. Mass: 759 kg (1,673 lb). Nation: USA. Agency: USAF. Manufacturer: Seal Beach. Program: Navstar. Class: Navigation. Type: Navigation satellite. Spacecraft: GPS Block 1. USAF Sat Cat: 10684 . COSPAR: 1978-020A. Apogee: 20,560 km (12,770 mi). Perigee: 20,249 km (12,582 mi). Inclination: 64.5000 deg. Period: 727.00 min. Summary: Also known as Navigational Development Satellite 1. Technology prototype of Navstar satellite..

1978 May 13 - . 10:34 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC3E. LV Family: Atlas. Launch Vehicle: Atlas F/SVS. LV Configuration: Atlas F/SVS 49F.
  • Navstar 2 - . Payload: GPS SVN 2 / OPS 5112. Mass: 759 kg (1,673 lb). Nation: USA. Agency: USAF. Manufacturer: Seal Beach. Program: Navstar. Class: Navigation. Type: Navigation satellite. Spacecraft: GPS Block 1. USAF Sat Cat: 10893 . COSPAR: 1978-047A. Apogee: 20,653 km (12,833 mi). Perigee: 19,523 km (12,131 mi). Inclination: 63.6000 deg. Period: 714.20 min. Summary: Also known as Navigational Development Satellite 2. Technology prototype of Navstar satellite..

1978 October 7 - . 00:28 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC3E. LV Family: Atlas. Launch Vehicle: Atlas F/SVS. LV Configuration: Atlas F/SVS 47F.
  • Navstar 3 - . Payload: GPS SVN 3 / OPS 5113. Mass: 759 kg (1,673 lb). Nation: USA. Agency: USAF. Manufacturer: Seal Beach. Program: Navstar. Class: Navigation. Type: Navigation satellite. Spacecraft: GPS Block 1. USAF Sat Cat: 11054 . COSPAR: 1978-093A. Apogee: 20,941 km (13,012 mi). Perigee: 20,706 km (12,866 mi). Inclination: 63.3000 deg. Period: 744.20 min. Summary: Technology prototype of Navstar satellite..

1978 December 11 - . 03:59 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC3E. LV Family: Atlas. Launch Vehicle: Atlas F/SVS. LV Configuration: Atlas F/SVS 39F.
  • Navstar 4 - . Payload: GPS SVN 4 / OPS 5114. Mass: 770 kg (1,690 lb). Nation: USA. Agency: USAF. Manufacturer: Seal Beach. Program: Navstar. Class: Navigation. Type: Navigation satellite. Spacecraft: GPS Block 1. USAF Sat Cat: 11141 . COSPAR: 1978-112A. Apogee: 21,012 km (13,056 mi). Perigee: 20,750 km (12,890 mi). Inclination: 64.6000 deg. Period: 746.50 min. Summary: Global Positioning System. First pre-opertional Navstar satellite..

1980 February 9 - . 23:08 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC3E. LV Family: Atlas. Launch Vehicle: Atlas F/SVS. LV Configuration: Atlas F/SVS 35F.
  • Navstar 5 - . Payload: GPS SVN 5 / OPS 5117. Mass: 770 kg (1,690 lb). Nation: USA. Agency: USAF. Manufacturer: Seal Beach. Program: Navstar. Class: Navigation. Type: Navigation satellite. Spacecraft: GPS Block 1. USAF Sat Cat: 11690 . COSPAR: 1980-011A. Apogee: 20,560 km (12,770 mi). Perigee: 19,805 km (12,306 mi). Inclination: 64.9000 deg. Period: 718.00 min. Summary: Global Positioning System..

1980 April 26 - . 22:00 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC3E. LV Family: Atlas. Launch Vehicle: Atlas F/SVS. LV Configuration: Atlas F/SVS 34F.
  • Navstar 6 - . Payload: GPS SVN 6 / OPS 5118. Mass: 770 kg (1,690 lb). Nation: USA. Agency: USAF. Manufacturer: Seal Beach. Program: Navstar. Class: Navigation. Type: Navigation satellite. Spacecraft: GPS Block 1. USAF Sat Cat: 11783 . COSPAR: 1980-032A. Apogee: 20,471 km (12,720 mi). Perigee: 19,387 km (12,046 mi). Inclination: 62.8000 deg. Period: 707.80 min. Summary: Global Positioning System..

1981 December 19 - . 01:10 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC3E. LV Family: Atlas. Launch Vehicle: Atlas E/SVS. LV Configuration: Atlas E/SVS 76E. FAILURE: Failure.. Failed Stage: 1.
  • Navstar 7 - . Payload: GPS SVN 7. Mass: 770 kg (1,690 lb). Nation: USA. Agency: USAF. Manufacturer: Seal Beach. Program: Navstar. Class: Navigation. Type: Navigation satellite. Spacecraft: GPS Block 1. Decay Date: 1981-12-18 . COSPAR: F811219A. Summary: Global Positioning System..

1983 July 14 - . 10:21 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC3W. LV Family: Atlas. Launch Vehicle: Atlas E/SGS-2. LV Configuration: Atlas E/SGS-2 75E.
  • Navstar 8 - . Payload: GPS SVN 8 / OPS 9794. Mass: 770 kg (1,690 lb). Nation: USA. Agency: USAF. Manufacturer: Seal Beach. Program: Navstar. Class: Navigation. Type: Navigation satellite. Spacecraft: GPS Block 1. USAF Sat Cat: 14189 . COSPAR: 1983-072A. Apogee: 21,229 km (13,191 mi). Perigee: 20,757 km (12,897 mi). Inclination: 64.2000 deg. Period: 751.10 min. Summary: Global Positioning System..

1984 June 13 - . 11:37 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC3W. LV Family: Atlas. Launch Vehicle: Atlas E/SGS-2. LV Configuration: Atlas E/SGS-2 42E.
  • USA 1 - . Payload: GPS SVN 9. Mass: 770 kg (1,690 lb). Nation: USA. Agency: USAF. Manufacturer: Seal Beach. Program: Navstar. Class: Navigation. Type: Navigation satellite. Spacecraft: GPS Block 1. USAF Sat Cat: 15039 . COSPAR: 1984-059A. Apogee: 21,194 km (13,169 mi). Perigee: 20,681 km (12,850 mi). Inclination: 64.2000 deg. Period: 748.80 min. Summary: Global Positioning System..

1984 September 8 - . 21:41 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC3W. LV Family: Atlas. Launch Vehicle: Atlas E/SGS-2. LV Configuration: Atlas E/SGS-2 14E.
  • USA 5 - . Payload: GPS SVN 10. Mass: 770 kg (1,690 lb). Nation: USA. Agency: USAF. Manufacturer: Seal Beach. Program: Navstar. Class: Navigation. Type: Navigation satellite. Spacecraft: GPS Block 1. USAF Sat Cat: 15271 . COSPAR: 1984-097A. Apogee: 21,203 km (13,174 mi). Perigee: 20,612 km (12,807 mi). Inclination: 61.9000 deg. Period: 747.60 min. Summary: Global Positioning System..

1985 October 9 - . 02:53 GMT - . Launch Site: Vandenberg. Launch Complex: Vandenberg SLC3W. LV Family: Atlas. Launch Vehicle: Atlas E/SGS-2. LV Configuration: Atlas E/SGS-2 55E.
  • USA 10 - . Payload: GPS SVN 11. Mass: 770 kg (1,690 lb). Nation: USA. Agency: USAF. Manufacturer: Seal Beach. Program: Navstar. Class: Navigation. Type: Navigation satellite. Spacecraft: GPS Block 1. USAF Sat Cat: 16129 . COSPAR: 1985-093A. Apogee: 21,673 km (13,466 mi). Perigee: 20,765 km (12,902 mi). Inclination: 65.0000 deg. Period: 760.40 min. Summary: Global Positioning System..

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