SL-8 R/B

SL-8 R/B is a spent rocket body associated with Russia (CIS), launched on 1981-12-17 from PKMTR on the RS-3 launch. With over 45 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 1,652 km and 1,786 km with an inclination of 83.0°. It travels at approximately 25,270 km/h (7.02 km/s), completing one full orbit every 2 hours 1 minutes — that’s roughly 11.92 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is thousands of years. Spent rocket bodies like SL-8 R/B are among the largest pieces of uncontrolled space debris and are priority targets for collision avoidance manoeuvres and future active debris removal efforts.

SL-8 R/B orbits at an average altitude of 1,719 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 SL-8 R/B’s average altitude, there are currently 14 active payloads and 50 tracked debris or rocket body fragments. This is a relatively sparse altitude band, containing less than 1% of all active satellites. With an inclination of 83.0°, SL-8 R/B passes over latitudes between 83.0°N and 83.0°S, providing near-global coverage including the polar regions. Polar and near-polar orbits are used for reconnaissance, weather monitoring and Earth-observation missions that need to image every part of the planet. Russia (CIS) operates approximately 1,286 active satellites in total, of which 3 share a similar altitude band with SL-8 R/B.