DIADEME 2

DIADEME 2 is an active satellite operated by CNES (France), launched on 1967-02-15 from Hammaguir, Algeria on the Diademe D-1D launch. After more than 59 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 577 km and 1,625 km with an inclination of 39.4°. It travels at approximately 26,294 km/h (7.30 km/s), completing one full orbit every 107 minutes — that’s roughly 13.42 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~500–1,000 years. Orbital Radar tracks DIADEME 2 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

DIADEME 2 orbits at an average altitude of 1,101 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 DIADEME 2’s average altitude, there are currently 437 active payloads and 504 tracked debris or rocket body fragments — notable neighbours include ONEWEB-0041. With an inclination of 39.4°, DIADEME 2 passes over latitudes between 39.4°N and 39.4°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, of which 2 share a similar altitude band with DIADEME 2.