SL-12 R/B(2)

SL-12 R/B(2) is a spent rocket body associated with Russia (CIS), launched on 1975-12-22 from Baikonur, Kazakhstan on the Gran' No. 11L launch. After more than 51 years in orbit, it is one of the longest-surviving objects in the space catalogue. It orbits in Geostationary Orbit (GEO) at altitudes between 35,659 km and 35,780 km with an inclination of 2.5°. It travels at approximately 11,078 km/h (3.08 km/s), completing one full orbit every ~24 hours (geosynchronous) — that’s roughly 1.01 orbits per day. At geostationary altitude, there is no meaningful atmospheric drag — this object will remain in orbit indefinitely unless actively deorbited. Spent rocket bodies like SL-12 R/B(2) are among the largest pieces of uncontrolled space debris and are priority targets for collision avoidance manoeuvres and future active debris removal efforts.

SL-12 R/B(2) occupies geostationary orbit at approximately 35,786 km above the equator, where its orbital period matches the Earth’s 24-hour rotation. From the ground, it appears to hover over a fixed point — ideal for broadcast television, weather monitoring and wideband communications. With an inclination of 2.5°, it traces a small figure-of-eight pattern relative to the equator rather than remaining perfectly stationary, which can indicate aging stationkeeping fuel or a deliberate inclined-orbit strategy. Within ±50 km of SL-12 R/B(2)’s average altitude, there are currently 29 active payloads and 30 tracked debris or rocket body fragments. Russia (CIS) operates approximately 1,286 active satellites in total, of which 11 share a similar altitude band with SL-12 R/B(2).