SL-8 R/B

SL-8 R/B is a spent rocket body associated with Russia (CIS), launched on 1994-09-27 from PKMTR on the Vektor launch. With over 32 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 369 km and 1,213 km with an inclination of 83.0°. It travels at approximately 26,857 km/h (7.46 km/s), completing one full orbit every 101 minutes — that’s roughly 14.30 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~25–100 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 791 km in the mid-LEO band, where atmospheric drag is minimal but radiation exposure remains manageable. Objects at this altitude persist for decades to centuries, making debris mitigation critical. This regime is popular for remote sensing constellations and scientific instruments that need stable, long-duration orbits. Within ±50 km of SL-8 R/B’s average altitude, there are currently 426 active payloads and 2,196 tracked debris or rocket body fragments — notable neighbours include NOAA 20, ONEWEB-0179, ONEWEB-0455. 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 1,288 active satellites in total, of which 62 share a similar altitude band with SL-8 R/B.