SL-12 DEB

SL-12 DEB is a tracked piece of space debris attributed to 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 835 km and 17,419 km with an inclination of 66.1°. It travels at approximately 18,257 km/h (5.07 km/s), completing one full orbit every 5 hours 20 minutes — that’s roughly 4.50 orbits per day. Its orbital eccentricity of 0.5350 gives it a noticeably elliptical path, with significant altitude variation between perigee and apogee. As orbital debris, SL-12 DEB poses a potential collision risk to operational satellites in nearby orbits and is continuously monitored by the U.S. Space Surveillance Network and other tracking systems.

SL-12 DEB orbits at an average altitude of 9,127 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 DEB’s average altitude, there are currently 1 active payload and 7 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 66.1°, SL-12 DEB passes over latitudes between 66.1°N and 66.1°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 1,285 active satellites in total.