USA 56

USA 56 is an active satellite operated by United States, launched on 1990-04-11 from Vandenberg SFB, California. With over 36 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 596 km and 678 km with an inclination of 89.9°. It travels at approximately 27,150 km/h (7.54 km/s), completing one full orbit every 97 minutes — that’s roughly 14.78 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~10–25 years. Orbital Radar tracks USA 56 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

USA 56 orbits at an average altitude of 637 km in the mid-LEO band, where atmospheric drag is minimal but radiation exposure remains manageable. Objects at this altitude persist for decades to centuries, making debris mitigation critical. This regime is popular for remote sensing constellations and scientific instruments that need stable, long-duration orbits. Within ±50 km of USA 56’s average altitude, there are currently 761 active payloads and 896 tracked debris or rocket body fragments — notable neighbours include AQUA, ONEWEB-0050. With an inclination of 89.9°, USA 56 passes over latitudes between 89.9°N and 89.9°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 12,339 active satellites in total, of which 328 share a similar altitude band with USA 56.