PEGASUS R/B

PEGASUS R/B is a spent rocket body associated with United States, launched on 2006-03-22 from Vandenberg Space Force Base, United States on the Space Technology 5 launch. With over 20 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Medium Earth Orbit (MEO) at altitudes between 292 km and 2,688 km with an inclination of 105.5°. It travels at approximately 25,635 km/h (7.12 km/s), completing one full orbit every 116 minutes — that’s roughly 12.44 orbits per day. Its orbital eccentricity of 0.1524 gives it a noticeably elliptical path, with significant altitude variation between perigee and apogee. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is thousands of years. Spent rocket bodies like PEGASUS R/B are among the largest pieces of uncontrolled space debris and are priority targets for collision avoidance manoeuvres and future active debris removal efforts.

PEGASUS R/B orbits at an average altitude of 1,490 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 PEGASUS R/B’s average altitude, there are currently 384 active payloads and 406 tracked debris or rocket body fragments. With an inclination of 105.5°, PEGASUS R/B passes over latitudes between 105.5°N and 105.5°S, providing near-global coverage including the polar regions. Polar and near-polar orbits are used for reconnaissance, weather monitoring and Earth-observation missions that need to image every part of the planet. United States operates approximately 13,201 active satellites in total, of which 12 share a similar altitude band with PEGASUS R/B.