OV1-9 R/B

OV1-9 R/B is a spent rocket body associated with United States, launched on 1966-12-11 from Vandenberg Space Force Base, United States on the OV1-9 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 476 km and 4,386 km with an inclination of 99.1°. It travels at approximately 24,226 km/h (6.73 km/s), completing one full orbit every 2 hours 17 minutes — that’s roughly 10.50 orbits per day. Its orbital eccentricity of 0.2221 gives it a noticeably elliptical path, with significant altitude variation between perigee and apogee. Spent rocket bodies like OV1-9 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.

OV1-9 R/B orbits at an average altitude of 2,431 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 OV1-9 R/B’s average altitude, there are currently 0 active payloads and 9 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 99.1°, OV1-9 R/B passes over latitudes between 99.1°N and 99.1°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.