SL-8 DEB

SL-8 DEB is a tracked piece of space debris attributed to Russia (CIS), launched on 1970-12-02 from PKMTR on the Ionosfernaya Stantsiya N launch. After more than 56 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 922 km and 929 km with an inclination of 74.0°. It travels at approximately 26,608 km/h (7.39 km/s), completing one full orbit every 104 minutes — that’s roughly 13.91 orbits per day. Its near-circular orbit (eccentricity close to zero) means it maintains a very consistent altitude throughout each revolution. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~100–500 years. As orbital debris, SL-8 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.

SL-8 DEB orbits at an average altitude of 926 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 SL-8 DEB’s average altitude, there are currently 247 active payloads and 1,177 tracked debris or rocket body fragments. With an inclination of 74.0°, SL-8 DEB passes over latitudes between 74.0°N and 74.0°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 66 share a similar altitude band with SL-8 DEB.