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. With over 41 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 664 km and 801 km with an inclination of 66.6°. It travels at approximately 26,967 km/h (7.49 km/s), completing one full orbit every 99 minutes — that’s roughly 14.48 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 733 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 359 active payloads and 1,849 tracked debris or rocket body fragments — notable neighbours include TERRA, AQUA, 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 1,286 active satellites in total, of which 43 share a similar altitude band with SL-12 DEB.