DELTA 1 R/B(2)

DELTA 1 R/B(2) is a spent rocket body associated with United States, launched on 1981-08-03 from Vandenberg SFB, California on the DE A launch. With over 45 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Medium Earth Orbit (MEO) at altitudes between 460 km and 23,219 km with an inclination of 90.9°. It travels at approximately 16,843 km/h (4.68 km/s), completing one full orbit every 6 hours 48 minutes — that’s roughly 3.53 orbits per day. Its orbital eccentricity of 0.6249 gives it a noticeably elliptical path, with significant altitude variation between perigee and apogee. Spent rocket bodies like DELTA 1 R/B(2) 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(2) orbits at an average altitude of 11,840 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. With an inclination of 90.9°, DELTA 1 R/B(2) passes over latitudes between 90.9°N and 90.9°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 12,413 active satellites in total.