USA 18

USA 18 is an active satellite operated by NRO / NRL (United States), launched on 1986-02-09 from Vandenberg Space Force Base, United States on the PARCAE 8 launch. With over 40 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 373 km and 1,459 km with an inclination of 63.3°. It travels at approximately 26,625 km/h (7.40 km/s), completing one full orbit every 103 minutes — that’s roughly 13.94 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~100–500 years. Orbital Radar tracks USA 18 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

USA 18 orbits at an average altitude of 916 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 18’s average altitude, there are currently 276 active payloads and 1,397 tracked debris or rocket body fragments. With an inclination of 63.3°, USA 18 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 13,204 active satellites in total, of which 133 share a similar altitude band with USA 18.