DIAMANT B-P4 R/B

DIAMANT B-P4 R/B is a spent rocket body associated with France, launched on 1975-02-06 from Guiana Space Centre, French Guiana on the Starlette launch. After more than 51 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 796 km and 1,115 km with an inclination of 49.8°. It travels at approximately 26,554 km/h (7.38 km/s), completing one full orbit every 104 minutes — that’s roughly 13.82 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~100–500 years. Spent rocket bodies like DIAMANT B-P4 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.

DIAMANT B-P4 R/B orbits at an average altitude of 956 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 DIAMANT B-P4 R/B’s average altitude, there are currently 393 active payloads and 1,281 tracked debris or rocket body fragments. With an inclination of 49.8°, DIAMANT B-P4 R/B passes over latitudes between 49.8°N and 49.8°S, covering the tropical and temperate zones where most of the world’s population resides. Low-to-mid inclination orbits are efficient to reach from equatorial and mid-latitude launch sites. France operates approximately 124 active satellites in total.