SL-6 DEB

SL-6 DEB is a tracked piece of space debris attributed to Russia (CIS), launched on 1981-09-11 from PKMTR on the Molniya-3 No. 28 launch. With over 45 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Medium Earth Orbit (MEO) at altitudes between 726 km and 13,685 km with an inclination of 63.0°. It travels at approximately 19,506 km/h (5.42 km/s), completing one full orbit every 4 hours 23 minutes — that’s roughly 5.48 orbits per day. Its orbital eccentricity of 0.4773 gives it a noticeably elliptical path, with significant altitude variation between perigee and apogee. As orbital debris, SL-6 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-6 DEB orbits at an average altitude of 7,206 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-6 DEB’s average altitude, there are currently 2 active payloads and 5 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 63.0°, SL-6 DEB passes over latitudes between 63.0°N and 63.0°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.