COSMOS 397 DEB

COSMOS 397 DEB is a tracked piece of space debris attributed to Russia (CIS), launched on 1971-02-25 from Baikonur Cosmodrome, Kazakhstan on the I2P launch. 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 556 km and 1,959 km with an inclination of 65.7°. It travels at approximately 26,023 km/h (7.23 km/s), completing one full orbit every 111 minutes — that’s roughly 13.01 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is thousands of 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 1,258 km in the uppermost reaches of Low Earth Orbit. At this altitude, orbital decay is effectively zero without active deorbiting, and coverage footprints are significantly larger than lower LEO, though at the cost of higher latency. Within ±50 km of COSMOS 397 DEB’s average altitude, there are currently 236 active payloads and 383 tracked debris or rocket body fragments — notable neighbours include ONEWEB-0013, ONEWEB-0017, ONEWEB-0020. 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 1,537 active satellites in total, of which 5 share a similar altitude band with COSMOS 397 DEB.