OPS 5111
A Block I GPS satellite (Navstar 1) | |
| Names | Navstar 1 NDS-1 GPS I-1 GPS SVN-1 |
|---|---|
| Mission type | Navigation Technology |
| Operator | U.S. Air Force |
| COSPAR ID | 1978-020A |
| SATCAT no. | 10684 |
| Mission duration | 5 years (planned) 7.25 years (achieved) |
| Spacecraft properties | |
| Spacecraft | Navstar |
| Spacecraft type | GPS Block I |
| Manufacturer | Rockwell Space Systems |
| Launch mass | 758 kg (1,671 lb) |
| Dimensions | Solar panel span: 5.3 m (17.4 ft) |
| Power | 400 watts |
| Start of mission | |
| Launch date | 22 February 1978, 23:44:00 UTC |
| Rocket | Atlas F / SGS-1 (Atlas-64F) |
| Launch site | Vandenberg, SLC-3E |
| Contractor | Convair General Dynamics |
| Entered service | 29 March 1978 |
| End of mission | |
| Deactivated | 17 July 1985 |
| Orbital parameters | |
| Reference system | Geocentric orbit |
| Regime | Medium Earth orbit (Semi-synchronous) |
| Perigee altitude | 20,095 km (12,486 mi) |
| Apogee altitude | 20,308 km (12,619 mi) |
| Inclination | 63.3° |
| Period | 718.70 minutes |
OPS 5111, also known as Navstar 1, NDS-1, GPS I-1 and GPS SVN-1, was an American navigation satellite launched in 1978 as part of the Global Positioning System development program. It was the first GPS satellite to be launched, and one of eleven Block I demonstration satellites.