COSMOS 2251 DEB

COSMOS 2251 DEB is a tracked piece of space debris attributed to Russia (CIS), launched on 1993-06-16 from PKMTR on the Strela-2M launch. With over 33 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 747 km and 1,131 km with an inclination of 74.1°. It travels at approximately 26,584 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. As orbital debris, COSMOS 2251 DEB poses a potential collision risk to operational satellites in nearby orbits and is continuously monitored by the U.S. Space Surveillance Network and other tracking systems.

COSMOS 2251 DEB orbits at an average altitude of 939 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 2251 DEB’s average altitude, there are currently 337 active payloads and 1,143 tracked debris or rocket body fragments. With an inclination of 74.1°, COSMOS 2251 DEB passes over latitudes between 74.1°N and 74.1°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 1,286 active satellites in total, of which 154 share a similar altitude band with COSMOS 2251 DEB.