USA 121

USA 121 is an active satellite operated by United States, launched on 1996-05-12 from Vandenberg SFB, California. With over 30 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 451 km and 1,722 km with an inclination of 63.3°. It travels at approximately 26,319 km/h (7.31 km/s), completing one full orbit every 107 minutes — that’s roughly 13.46 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~500–1,000 years. Orbital Radar tracks USA 121 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

USA 121 orbits at an average altitude of 1,087 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 USA 121’s average altitude, there are currently 182 active payloads and 402 tracked debris or rocket body fragments — notable neighbours include ONEWEB-0041. With an inclination of 63.3°, USA 121 passes over latitudes between 63.3°N and 63.3°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 12,339 active satellites in total, of which 12 share a similar altitude band with USA 121.