GPS Block 1
Part of the Global Positioning System (GPS) program
GPS Block 1 satellites formed the GPS Demonstration system and were followed by the Block 2 operational system.
Spacecraft
3-Axis stabilized, nadir pointing using reaction wheels. Dual solar arrays supply over 400 watts (EOL). NiCd batteries. S-Band (SGLS) communications for control and telemetry. UHF cross-link between spacecraft. Hydrazine propulsion system.
Payload
Two L-Band navigation signals at 1575.42 MHz (L1) and 1227.60 MHz (L2)
| Country of Origin | United States |
| Customer/User | U.S. Air Force |
| Manufacturer(s) | Rockwell Space Systems |
| Size | 5.3 m across with solar panels deployed |
| Orbit | 20,200 km circular (12 hour period) 63 deg inclination, 6 orbit planes |
| Design Life | 5 years |
Launch Facts
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| Name | Int'l Desig. | Date | Site | Vehicle | Orbit | Mass(kg) |
| Notes | ||||||
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| GPS 1-1 (Navstar 1) | 1978-020A | 2/22/78 | WSMC | Atlas F | MEO | 450 |
| Also known as Navigational Development Satellite 1; 1st generation Global Positioning System | ||||||
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| GPS 1-2 (Navstar 2) | 1978-047A | 5/13/78 | WSMC | Atlas F | MEO | 453 |
| Also known as Navigational Development Satellite 2; 1st generation Global Positioning System | ||||||
| ||||||
| GPS 1-3 (Navstar 3) | 1978-093A | 10/7/78 | WSMC | Atlas F | MEO | 450 |
| 1st generation Global Positioning System | ||||||
| ||||||
| GPS 1-4 (Navstar 4) | 1978-112A | 12/11/78 | WSMC | Atlas F | MEO | 450 |
| 1st generation Global Positioning System | ||||||
| ||||||
| GPS 1-5 (Navstar 5) | 1980-011A | 2/9/80 | WSMC | Atlas F | MEO | 433 |
| 1st generation Global Positioning System | ||||||
| ||||||
| GPS 1-6 (Navstar 6) | 1980-032A | 4/26/80 | WSMC | Atlas F | MEO | 450 |
| 1st generation Global Positioning System | ||||||
| ||||||
| GPS 1-7 (Navstar 7) | none | 12/18/81 | WSMC | Atlas E | FTO | 163 |
| 1st generation Global Positioning System | ||||||
| ||||||
| GPS 1-8 (Navstar 8) | 1983-072A | 7/14/83 | WSMC | Atlas E | MEO | 163 |
| 1st generation Global Positioning System | ||||||
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| GPS 1-9 (Navstar 9) | 1984-059A | 6/13/84 | WSMC | Atlas E | MEO | 433 |
| 1st generation Global Positioning System | ||||||
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| GPS 1-10 (USA 5) | 1984-097A | 9/8/84 | WSMC | Atlas E | MEO | 770 |
| Also known as Navstar 10; 1st generation Global Positioning System | ||||||
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| GPS 1-11 (USA 10) | 1985-093A | 10/9/85 | WSMC | Atlas E | MEO | 163 |
| Also known as Navstar 11; 1st generation Global Positioning System | ||||||
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