DELTA 1 R/B(2) *

DELTA 1 R/B(2) * is a spent rocket body associated with United States, launched on 1966-10-26 from Cape Canaveral, Florida on the INTELSAT II F-1 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 421 km and 21,238 km with an inclination of 17.8°. It travels at approximately 17,330 km/h (4.81 km/s), completing one full orbit every 6 hours 14 minutes — that’s roughly 3.85 orbits per day. Its orbital eccentricity of 0.6051 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 10,830 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(2) *’s average altitude, there are currently 2 active payloads and 4 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 17.8°, DELTA 1 R/B(2) * passes over latitudes between 17.8°N and 17.8°S, concentrating coverage over equatorial and near-equatorial regions. Low-inclination orbits maximise revisit rates over specific tropical zones. United States operates approximately 12,413 active satellites in total.