DELTA 1 R/B

DELTA 1 R/B is a spent rocket body associated with United States, launched on 1972-10-15 from Vandenberg Space Force Base, United States on the ITOS D launch. After more than 54 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 916 km and 1,463 km with an inclination of 102.8°. It travels at approximately 26,139 km/h (7.26 km/s), completing one full orbit every 109 minutes — that’s roughly 13.19 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~500–1,000 years. Spent rocket bodies like DELTA 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.

DELTA 1 R/B orbits at an average altitude of 1,190 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 DELTA 1 R/B’s average altitude, there are currently 869 active payloads and 294 tracked debris or rocket body fragments — notable neighbours include ONEWEB-0012, ONEWEB-0010, ONEWEB-0008. With an inclination of 102.8°, DELTA 1 R/B passes over latitudes between 102.8°N and 102.8°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 7 share a similar altitude band with DELTA 1 R/B.