SCOUT A-1 R/B

SCOUT A-1 R/B is a spent rocket body associated with United States, launched on 1973-10-30 from Vandenberg Space Force Base, United States on the NNS O-20 launch. After more than 53 years in orbit, it is one of the longest-surviving objects in the space catalogue. It orbits in Low Earth Orbit (LEO) at altitudes between 883 km and 1,118 km with an inclination of 89.9°. It travels at approximately 26,472 km/h (7.35 km/s), completing one full orbit every 105 minutes — that’s roughly 13.70 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~500–1,000 years. Spent rocket bodies like SCOUT A-1 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.

SCOUT A-1 R/B orbits at an average altitude of 1,001 km in the upper LEO band, where atmospheric drag is negligible and objects can persist for centuries to millennia. This altitude is used by broadband constellations like OneWeb and by scientific missions requiring stable orbits far from the densest debris bands. Within ±50 km of SCOUT A-1 R/B’s average altitude, there are currently 290 active payloads and 1,060 tracked debris or rocket body fragments. With an inclination of 89.9°, SCOUT A-1 R/B passes over latitudes between 89.9°N and 89.9°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 13,206 active satellites in total, of which 69 share a similar altitude band with SCOUT A-1 R/B.