PEGASUS R/B

PEGASUS R/B is a spent rocket body associated with United States, launched on 2003-04-28 from Cape Canaveral, Florida on the GALEX launch. With over 23 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 673 km and 681 km with an inclination of 29.0°. It travels at approximately 27,073 km/h (7.52 km/s), completing one full orbit every 98 minutes — that’s roughly 14.65 orbits per day. Its near-circular orbit (eccentricity close to zero) means it maintains a very consistent altitude throughout each revolution. 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 677 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 539 active payloads and 1,253 tracked debris or rocket body fragments — notable neighbours include TERRA, AQUA, LANDSAT 9. With an inclination of 29.0°, PEGASUS R/B passes over latitudes between 29.0°N and 29.0°S, covering the tropical and temperate zones where most of the world’s population resides. Low-to-mid inclination orbits are efficient to reach from equatorial and mid-latitude launch sites. United States operates approximately 12,413 active satellites in total, of which 276 share a similar altitude band with PEGASUS R/B.