ATLAS H R/B

ATLAS H R/B is a spent rocket body associated with United States, launched on 1987-05-15 from Vandenberg SFB, California on the PARCAE 9 launch. With over 39 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 545 km and 1,590 km with an inclination of 63.3°. It travels at approximately 26,353 km/h (7.32 km/s), completing one full orbit every 107 minutes — that’s roughly 13.51 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~500–1,000 years. Spent rocket bodies like ATLAS H 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.

ATLAS H R/B orbits at an average altitude of 1,068 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 ATLAS H R/B’s average altitude, there are currently 187 active payloads and 429 tracked debris or rocket body fragments — notable neighbours include ONEWEB-0041. With an inclination of 63.3°, ATLAS H R/B passes over latitudes between 63.3°N and 63.3°S, covering most populated land masses in both hemispheres. This mid-inclination band balances global coverage with efficient launch energy requirements. United States operates approximately 12,413 active satellites in total, of which 14 share a similar altitude band with ATLAS H R/B.