Geosat
| Artist's interpretation of the Geosat satellite | |
| Mission type | Earth science | 
|---|---|
| Operator | United States Navy | 
| COSPAR ID | 1985-021A | 
| SATCAT no. | 15595 | 
| Mission duration | 5 Years | 
| Spacecraft properties | |
| Dry mass | 635.0 kilograms (1,399.9 lb) | 
| Start of mission | |
| Launch date | March 13, 1985, 02:00 UTC | 
| Rocket | Atlas E OIS | 
| Launch site | Vandenberg SLC-3W | 
| End of mission | |
| Deactivated | January 1990 | 
| Orbital parameters | |
| Reference system | Geocentric | 
| Regime | LEO | 
| Semi-major axis | 7,146.2 kilometres (4,440.4 mi) | 
| Eccentricity | 0.00398 | 
| Perigee altitude | 757 kilometres (470 mi) | 
| Apogee altitude | 814 kilometres (506 mi) | 
| Inclination | 108.0596 degrees | 
| Period | 100.6 minutes | 
| RAAN | 309.0682 degrees | 
| Argument of perigee | 276.8275 degrees | 
| Mean anomaly | 131.8715 degrees | 
| Mean motion | 14.37442186 | 
| Epoch | 9 December 2013 | 
| Revolution no. | 50565 | 
The GEOSAT (GEOdetic SATellite) was a U.S. Navy Earth observation satellite, launched on March 12, 1985 into an 800 km, 108° inclination orbit, with a nodal period of about 6040 seconds. The satellite carried a radar altimeter capable of measuring the distance from the satellite to sea surface with a relative precision of about 5 cm. The initial phase was an 18-month classified Geodetic Mission (GM) have a ground-track with a near-23-day repeat with closure to within 50 kilometers. The effect of atmospheric drag was such that by fall 1986 GEOSAT was in an almost exact 23-day repeat orbit.