SL-8 R/B

SL-8 R/B is a spent rocket body associated with Russia (CIS), launched on 1983-04-12 from PKMTR on the Strela-2M launch. With over 43 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 762 km and 770 km with an inclination of 74.0°. It travels at approximately 26,904 km/h (7.47 km/s), completing one full orbit every 100 minutes — that’s roughly 14.38 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 ~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 766 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 386 active payloads and 2,096 tracked debris or rocket body fragments — notable neighbours include ONEWEB-0179, ONEWEB-0455. With an inclination of 74.0°, SL-8 R/B 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 1,287 active satellites in total, of which 50 share a similar altitude band with SL-8 R/B.