SL-12 R/B(2)

SL-12 R/B(2) is a spent rocket body associated with Russia (CIS), launched on 1987-09-16 from Baikonur, Kazakhstan on the Uragan No. 33L launch. With over 39 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Medium Earth Orbit (MEO) at altitudes between 19,083 km and 19,127 km with an inclination of 65.6°. It travels at approximately 14,240 km/h (3.96 km/s), completing one full orbit every 11 hours 15 minutes — that’s roughly 2.13 orbits per day. 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) orbits at an average altitude of 19,105 km in Medium Earth Orbit, the region between LEO and GEO (2,000–35,786 km). MEO’s higher altitude gives each satellite a much larger ground footprint than LEO, meaning fewer spacecraft are needed for global coverage — but signal latency is higher and radiation from the Van Allen belts is a significant design constraint. Within ±50 km of SL-12 R/B(2)’s average altitude, there are currently 142 active payloads and 50 tracked debris or rocket body fragments — notable neighbours include COSMOS 1413 (GLONASS), COSMOS 1414 (GLONASS), COSMOS 1415 (GLONASS). With an inclination of 65.6°, SL-12 R/B(2) passes over latitudes between 65.6°N and 65.6°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 142 share a similar altitude band with SL-12 R/B(2).