OV1-4

OV1-4 is an active satellite operated by USAF OAR (United States), launched on 1966-03-30 from Vandenberg Space Force Base, United States on the OV1-4S launch. After more than 60 years in orbit, it is one of the longest-surviving objects in the space catalogue. It orbits in Low Earth Orbit (LEO) at altitudes between 877 km and 999 km with an inclination of 144.5°. It travels at approximately 26,585 km/h (7.38 km/s), completing one full orbit every 104 minutes — that’s roughly 13.87 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~100–500 years. Orbital Radar tracks OV1-4 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

OV1-4 orbits at an average altitude of 938 km in the upper LEO band, where atmospheric drag is negligible and objects can persist for centuries to millennia. This altitude is used by broadband constellations like OneWeb and by scientific missions requiring stable orbits far from the densest debris bands. Within ±50 km of OV1-4’s average altitude, there are currently 444 active payloads and 1,371 tracked debris or rocket body fragments. With an inclination of 144.5°, OV1-4 passes over latitudes between 144.5°N and 144.5°S, providing near-global coverage including the polar regions. Polar and near-polar orbits are used for reconnaissance, weather monitoring and Earth-observation missions that need to image every part of the planet. United States operates approximately 13,279 active satellites in total, of which 173 share a similar altitude band with OV1-4.