NNSS 19 (TRANSIT 19)

NNSS 19 (TRANSIT 19) is an active satellite operated by USN NAVAIR (United States), launched on 1970-08-27 from Vandenberg Space Force Base, United States on the NNS O-19 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 938 km and 1,196 km with an inclination of 90.0°. It travels at approximately 26,354 km/h (7.32 km/s), completing one full orbit every 107 minutes — that’s roughly 13.51 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~500–1,000 years. Orbital Radar tracks NNSS 19 (TRANSIT 19) in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

NNSS 19 (TRANSIT 19) orbits at an average altitude of 1,067 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 NNSS 19 (TRANSIT 19)’s average altitude, there are currently 309 active payloads and 582 tracked debris or rocket body fragments — notable neighbours include ONEWEB-0041. With an inclination of 90.0°, NNSS 19 (TRANSIT 19) passes over latitudes between 90.0°N and 90.0°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 13,279 active satellites in total, of which 41 share a similar altitude band with NNSS 19 (TRANSIT 19).