USA 61

USA 61 is an active satellite operated by NRO / NRL (United States), launched on 1990-06-08 from Cape Canaveral Space Force Station, United States on the SLDCOM 1/INTRUDER 1 launch. With over 36 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 373 km and 1,670 km with an inclination of 63.3°. It travels at approximately 26,435 km/h (7.34 km/s), completing one full orbit every 106 minutes — that’s roughly 13.64 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~500–1,000 years. Orbital Radar tracks USA 61 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

USA 61 orbits at an average altitude of 1,022 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 61’s average altitude, there are currently 463 active payloads and 927 tracked debris or rocket body fragments. With an inclination of 63.3°, USA 61 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 13,340 active satellites in total, of which 43 share a similar altitude band with USA 61.