ATLAS H R/B

ATLAS H R/B is a spent rocket body associated with United States, launched on 1986-02-09 from Vandenberg SFB, California on the PARCAE 8 launch. With over 40 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 766 km and 1,200 km with an inclination of 63.3°. It travels at approximately 26,504 km/h (7.36 km/s), completing one full orbit every 105 minutes — that’s roughly 13.75 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~100–500 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 983 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 300 active payloads and 942 tracked debris or rocket body fragments. 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 88 share a similar altitude band with ATLAS H R/B.