COSMOS 651

COSMOS 651 is an active satellite operated by Soviet Navy (Russia (CIS)), launched on 1974-05-15 from Baikonur Cosmodrome, Kazakhstan on the US-A reactor launch. After more than 52 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 891 km and 945 km with an inclination of 65.0°. It travels at approximately 26,622 km/h (7.39 km/s), completing one full orbit every 103 minutes — that’s roughly 13.93 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~100–500 years. Orbital Radar tracks COSMOS 651 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

COSMOS 651 orbits at an average altitude of 918 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 COSMOS 651’s average altitude, there are currently 317 active payloads and 1,418 tracked debris or rocket body fragments. With an inclination of 65.0°, COSMOS 651 passes over latitudes between 65.0°N and 65.0°S, covering most populated land masses in both hemispheres. This mid-inclination band balances global coverage with efficient launch energy requirements. Russia (CIS) operates approximately 1,553 active satellites in total, of which 67 share a similar altitude band with COSMOS 651.