SL-12 DEB

SL-12 DEB is a tracked piece of space debris attributed to Russia (CIS), launched on 1985-05-30 from Baikonur, Kazakhstan on the Tselina-2 launch. With over 41 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 707 km and 777 km with an inclination of 66.6°. It travels at approximately 26,949 km/h (7.49 km/s), completing one full orbit every 100 minutes — that’s roughly 14.45 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~25–100 years. 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 742 km in the mid-LEO band, where atmospheric drag is minimal but radiation exposure remains manageable. Objects at this altitude persist for decades to centuries, making debris mitigation critical. This regime is popular for remote sensing constellations and scientific instruments that need stable, long-duration orbits. Within ±50 km of SL-12 DEB’s average altitude, there are currently 366 active payloads and 1,896 tracked debris or rocket body fragments — notable neighbours include LANDSAT 9. With an inclination of 66.6°, SL-12 DEB passes over latitudes between 66.6°N and 66.6°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 1,285 active satellites in total, of which 47 share a similar altitude band with SL-12 DEB.