SL-12 R/B(AUX MOTOR)

SL-12 R/B(AUX MOTOR) is a spent rocket body associated with Russia (CIS), launched on 1985-05-17 from Baikonur, Kazakhstan on the Uragan No. 20L launch. With over 41 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Medium Earth Orbit (MEO) at altitudes between 323 km and 16,129 km with an inclination of 51.8°. It travels at approximately 18,812 km/h (5.23 km/s), completing one full orbit every 4 hours 53 minutes — that’s roughly 4.92 orbits per day. Its orbital eccentricity of 0.5414 gives it a noticeably elliptical path, with significant altitude variation between perigee and apogee. Spent rocket bodies like SL-12 R/B(AUX MOTOR) 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(AUX MOTOR) orbits at an average altitude of 8,226 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(AUX MOTOR)’s average altitude, there are currently 0 active payloads and 4 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 51.8°, SL-12 R/B(AUX MOTOR) passes over latitudes between 51.8°N and 51.8°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.