VANGUARD R/B

VANGUARD R/B is a spent rocket body associated with United States, launched on 1959-02-17 from Cape Canaveral Space Force Station, United States. After more than 67 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 554 km and 3,284 km with an inclination of 32.9°. It travels at approximately 24,963 km/h (6.93 km/s), completing one full orbit every 2 hours 5 minutes — that’s roughly 11.49 orbits per day. Its orbital eccentricity of 0.1647 gives it a noticeably elliptical path, with significant altitude variation between perigee and apogee. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is thousands of years. 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 1,919 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 5 active payloads and 27 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 32.9°, VANGUARD R/B passes over latitudes between 32.9°N and 32.9°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.