SL-12 DEB

SL-12 DEB is a tracked piece of space debris attributed to Russia (CIS), launched on 1989-12-27 from Baikonur, Kazakhstan on the Al'tair No. 14L launch. With over 37 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Medium Earth Orbit (MEO) at altitudes between 650 km and 5,506 km with an inclination of 46.1°. It travels at approximately 23,382 km/h (6.49 km/s), completing one full orbit every 2 hours 33 minutes — that’s roughly 9.44 orbits per day. Its orbital eccentricity of 0.2570 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 3,078 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 6 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 46.1°, SL-12 DEB passes over latitudes between 46.1°N and 46.1°S, covering the tropical and temperate zones where most of the world’s population resides. Low-to-mid inclination orbits are efficient to reach from equatorial and mid-latitude launch sites. Russia (CIS) operates approximately 1,285 active satellites in total.