SCOUT D-1 R/B

SCOUT D-1 R/B is a spent rocket body associated with United States, launched on 1977-10-28 from Vandenberg SFB, California on the NNS O-11 launch. With over 49 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 1,059 km and 1,097 km with an inclination of 89.7°. It travels at approximately 26,334 km/h (7.32 km/s), completing one full orbit every 107 minutes — that’s roughly 13.48 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 D-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 D-1 R/B orbits at an average altitude of 1,078 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 D-1 R/B’s average altitude, there are currently 187 active payloads and 411 tracked debris or rocket body fragments — notable neighbours include ONEWEB-0041. With an inclination of 89.7°, SCOUT D-1 R/B passes over latitudes between 89.7°N and 89.7°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 14 share a similar altitude band with SCOUT D-1 R/B.