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 680 km and 838 km with an inclination of 73.9°. It travels at approximately 26,917 km/h (7.48 km/s), completing one full orbit every 100 minutes — that’s roughly 14.40 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~25–100 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 759 km in the mid-LEO band, where atmospheric drag is minimal but radiation exposure remains manageable. Objects at this altitude persist for decades to centuries, making debris mitigation critical. This regime is popular for remote sensing constellations and scientific instruments that need stable, long-duration orbits. Within ±50 km of COSMOS 2251 DEB’s average altitude, there are currently 358 active payloads and 2,029 tracked debris or rocket body fragments — notable neighbours include ONEWEB-0179. With an inclination of 73.9°, COSMOS 2251 DEB passes over latitudes between 73.9°N and 73.9°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 46 share a similar altitude band with COSMOS 2251 DEB.