PEGASUS R/B

PEGASUS R/B is a spent rocket body associated with United States, launched on 1994-05-19 from Vandenberg SFB, California on the STEP 2 launch. With over 32 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 560 km and 719 km with an inclination of 82.0°. It travels at approximately 27,145 km/h (7.54 km/s), completing one full orbit every 98 minutes — that’s roughly 14.77 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~10–25 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 640 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 PEGASUS R/B’s average altitude, there are currently 747 active payloads and 926 tracked debris or rocket body fragments — notable neighbours include TERRA, AQUA, ONEWEB-0050. With an inclination of 82.0°, PEGASUS R/B passes over latitudes between 82.0°N and 82.0°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 12,413 active satellites in total, of which 329 share a similar altitude band with PEGASUS R/B.