SL-12 R/B(2)

SL-12 R/B(2) is a spent rocket body associated with Russia (CIS), launched on 1998-08-30 from Baikonur, Kazakhstan on the Astra 2A launch. With over 28 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Medium Earth Orbit (MEO) at altitudes between 7,883 km and 35,864 km with an inclination of 14.8°. It travels at approximately 13,524 km/h (3.76 km/s), completing one full orbit every 13 hours 8 minutes — that’s roughly 1.83 orbits per day. Its orbital eccentricity of 0.4953 gives it a noticeably elliptical path, with significant altitude variation between perigee and apogee. 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 21,874 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 1 active payload and 21 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 14.8°, SL-12 R/B(2) passes over latitudes between 14.8°N and 14.8°S, concentrating coverage over equatorial and near-equatorial regions. Low-inclination orbits maximise revisit rates over specific tropical zones. Russia (CIS) operates approximately 1,286 active satellites in total.