OPTUS B1 R/B(STAR 63F)

OPTUS B1 R/B(STAR 63F) is a spent rocket body associated with Australia, launched on 1992-08-13 from Xichang, China on the Optus B1 launch. With over 34 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Medium Earth Orbit (MEO) at altitudes between 464 km and 36,040 km with an inclination of 22.9°. It travels at approximately 14,484 km/h (4.02 km/s), completing one full orbit every 10 hours 41 minutes — that’s roughly 2.25 orbits per day. Its orbital eccentricity of 0.7224 gives it a noticeably elliptical path, with significant altitude variation between perigee and apogee. Spent rocket bodies like OPTUS B1 R/B(STAR 63F) are among the largest pieces of uncontrolled space debris and are priority targets for collision avoidance manoeuvres and future active debris removal efforts.

OPTUS B1 R/B(STAR 63F) orbits at an average altitude of 18,252 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 OPTUS B1 R/B(STAR 63F)’s average altitude, there are currently 1 active payload and 36 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 22.9°, OPTUS B1 R/B(STAR 63F) passes over latitudes between 22.9°N and 22.9°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. Australia operates approximately 41 active satellites in total.