DELTA 1 R/B

DELTA 1 R/B is a spent rocket body associated with United States, launched on 1963-05-07 from Cape Canaveral Space Force Station, United States on the Telstar 2 launch. After more than 63 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 967 km and 10,778 km with an inclination of 42.8°. It travels at approximately 20,541 km/h (5.71 km/s), completing one full orbit every 3 hours 45 minutes — that’s roughly 6.40 orbits per day. Its orbital eccentricity of 0.4007 gives it a noticeably elliptical path, with significant altitude variation between perigee and apogee. Spent rocket bodies like DELTA 1 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.

DELTA 1 R/B orbits at an average altitude of 5,873 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 DELTA 1 R/B’s average altitude, there are currently 4 active payloads and 8 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 42.8°, DELTA 1 R/B passes over latitudes between 42.8°N and 42.8°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, of which 3 share a similar altitude band with DELTA 1 R/B.