VANGUARD R/B

VANGUARD R/B is a spent rocket body associated with United States, launched on 1958-03-17 from Cape Canaveral Space Force Station, United States. After more than 68 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 657 km and 4,210 km with an inclination of 34.3°. It travels at approximately 24,223 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 0.2018 gives it a noticeably elliptical path, with significant altitude variation between perigee and apogee. Spent rocket bodies like VANGUARD 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.

VANGUARD R/B orbits at an average altitude of 2,434 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 VANGUARD 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 34.3°, VANGUARD R/B passes over latitudes between 34.3°N and 34.3°S, covering the tropical and temperate zones where most of the world’s population resides. Low-to-mid inclination orbits are efficient to reach from equatorial and mid-latitude launch sites. United States operates approximately 13,206 active satellites in total.