COSMOS 397 DEB

COSMOS 397 DEB is a tracked piece of space debris attributed to Russia (CIS), launched on 1971-02-25 from Baikonur, Kazakhstan. After more than 55 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 516 km and 1,108 km with an inclination of 65.7°. It travels at approximately 26,818 km/h (7.45 km/s), completing one full orbit every 101 minutes — that’s roughly 14.24 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~100–500 years. As orbital debris, COSMOS 397 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 397 DEB orbits at an average altitude of 812 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 397 DEB’s average altitude, there are currently 423 active payloads and 2,306 tracked debris or rocket body fragments — notable neighbours include NOAA 20, ONEWEB-0179, ONEWEB-0455. With an inclination of 65.7°, COSMOS 397 DEB passes over latitudes between 65.7°N and 65.7°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 84 share a similar altitude band with COSMOS 397 DEB.