INSAT 1B R/B(PAM-D)

INSAT 1B R/B(PAM-D) is a spent rocket body associated with United States, launched on 1983-08-30 from Cape Canaveral Space Force Station, United States on the OV-099 PAM deploy launch. With over 43 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Medium Earth Orbit (MEO) at altitudes between 302 km and 19,319 km with an inclination of 24.4°. It travels at approximately 17,867 km/h (4.96 km/s), completing one full orbit every 5 hours 42 minutes — that’s roughly 4.21 orbits per day. Its orbital eccentricity of 0.5876 gives it a noticeably elliptical path, with significant altitude variation between perigee and apogee. Spent rocket bodies like INSAT 1B R/B(PAM-D) are among the largest pieces of uncontrolled space debris and are priority targets for collision avoidance manoeuvres and future active debris removal efforts.

INSAT 1B R/B(PAM-D) orbits at an average altitude of 9,811 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 INSAT 1B R/B(PAM-D)’s average altitude, there are currently 0 active payloads and 11 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 24.4°, INSAT 1B R/B(PAM-D) passes over latitudes between 24.4°N and 24.4°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 13,201 active satellites in total.