 OSCAR 4 with exterior panels removed | |
| Mission type | Communications |
|---|---|
| Operator | Project OSCAR / DoD |
| COSPAR ID | 1965-108C |
| SATCAT no. | 01902 |
| Spacecraft properties | |
| Launch mass | 18.1 kilograms (40 lb) |
| Start of mission | |
| Launch date | 21 December 1965 |
| Rocket | Titan IIIC 3C-8 |
| Launch site | Cape Canaveral LC-41 |
| End of mission | |
| Decay date | 12 April 1976 |
| Orbital parameters | |
| Reference system | Geocentric |
| Regime | Geostationary (planned); Geostationary transfer orbit (actual) |
| Eccentricity | 0.71843 |
| Perigee altitude | 162 kilometers (101 mi) |
| Apogee altitude | 33,561 kilometers (20,854 mi) |
| Inclination | 26.80 degrees |
| Period | 587.4 minutes |
| Epoch | 20 December 1965 |
OSCAR IV (a.k.a. OSCAR 4) was the fourth amateur radio satellite launched by Project OSCAR and the first targeted for Geostationary orbit on 12 December 1965. The satellite was launched piggyback with three United States Air Force satellites on a Titan IIIC launch vehicle. Due to a booster failure, OSCAR 4 was placed in an unplanned and largely unusable Geostationary transfer orbit.