SERT 2

SERT 2 is an active satellite operated by NASA LeRC (United States), launched on 1970-02-04 from Vandenberg Space Force Base, United States on the SERT 2 launch. After more than 56 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 1,037 km and 1,043 km with an inclination of 99.3°. It travels at approximately 26,402 km/h (7.33 km/s), completing one full orbit every 106 minutes — that’s roughly 13.59 orbits per day. Its near-circular orbit (eccentricity close to zero) means it maintains a very consistent altitude throughout each revolution. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~500–1,000 years. Orbital Radar tracks SERT 2 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

SERT 2 orbits at an average altitude of 1,040 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 SERT 2’s average altitude, there are currently 333 active payloads and 689 tracked debris or rocket body fragments — notable neighbours include ONEWEB-0041. With an inclination of 99.3°, SERT 2 passes over latitudes between 99.3°N and 99.3°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 13,276 active satellites in total, of which 40 share a similar altitude band with SERT 2.