COSMOS 839 DEB *

COSMOS 839 DEB * is a tracked piece of space debris attributed to Russia (CIS), launched on 1976-07-08 from PKMTR. After more than 50 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 563 km and 1,945 km with an inclination of 65.7°. It travels at approximately 26,029 km/h (7.23 km/s), completing one full orbit every 111 minutes — that’s roughly 13.02 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is thousands of years. As orbital debris, COSMOS 839 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 839 DEB * orbits at an average altitude of 1,254 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 839 DEB *’s average altitude, there are currently 283 active payloads and 287 tracked debris or rocket body fragments — notable neighbours include ONEWEB-0013, ONEWEB-0017, ONEWEB-0020. With an inclination of 65.7°, COSMOS 839 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.