ASTEX 1

ASTEX 1 is an active satellite operated by USAF STP (United States), launched on 1971-10-17 from Vandenberg Space Force Base, United States on the ASTEX P71-2 launch. After more than 55 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 710 km and 735 km with an inclination of 92.7°. It travels at approximately 26,986 km/h (7.50 km/s), completing one full orbit every 99 minutes — that’s roughly 14.51 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~25–100 years. Orbital Radar tracks ASTEX 1 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

ASTEX 1 orbits at an average altitude of 723 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 ASTEX 1’s average altitude, there are currently 325 active payloads and 1,889 tracked debris or rocket body fragments — notable neighbours include TERRA, AQUA, ONEWEB-0179. With an inclination of 92.7°, ASTEX 1 passes over latitudes between 92.7°N and 92.7°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 104 share a similar altitude band with ASTEX 1.