THOR AGENA D R/B

THOR AGENA D R/B is a spent rocket body associated with United States, launched on 1966-06-24 from Vandenberg Space Force Base, United States on the Pageos A launch. After more than 60 years in orbit, it is one of the longest-surviving objects in the space catalogue. It orbits in Medium Earth Orbit (MEO) at altitudes between 4,178 km and 4,279 km with an inclination of 87.0°. It travels at approximately 22,076 km/h (6.13 km/s), completing one full orbit every 3 hours 1 minutes — that’s roughly 7.95 orbits per day. Spent rocket bodies like THOR AGENA D R/B are among the largest pieces of uncontrolled space debris and are priority targets for collision avoidance manoeuvres and future active debris removal efforts.

THOR AGENA D R/B orbits at an average altitude of 4,229 km in Medium Earth Orbit, the region between LEO and GEO (2,000–35,786 km). MEO’s higher altitude gives each satellite a much larger ground footprint than LEO, meaning fewer spacecraft are needed for global coverage — but signal latency is higher and radiation from the Van Allen belts is a significant design constraint. Within ±50 km of THOR AGENA D R/B’s average altitude, there are currently 0 active payloads and 3 tracked debris or rocket body fragments. This is a relatively sparse altitude band, containing less than 1% of all active satellites. With an inclination of 87.0°, THOR AGENA D R/B passes over latitudes between 87.0°N and 87.0°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 13,206 active satellites in total.