THOR AGENA D R/B

THOR AGENA D R/B is a spent rocket body associated with United States, launched on 1965-03-09 from Vandenberg Space Force Base, United States on the Secor Type II S/N 1 launch. After more than 61 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 884 km and 919 km with an inclination of 70.1°. It travels at approximately 26,652 km/h (7.40 km/s), completing one full orbit every 103 minutes — that’s roughly 13.98 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~100–500 years. Spent rocket bodies like THOR AGENA D 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.

THOR AGENA D R/B orbits at an average altitude of 902 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 THOR AGENA D R/B’s average altitude, there are currently 264 active payloads and 1,584 tracked debris or rocket body fragments. With an inclination of 70.1°, THOR AGENA D R/B passes over latitudes between 70.1°N and 70.1°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 13,206 active satellites in total, of which 112 share a similar altitude band with THOR AGENA D R/B.