H-2A R/B

H-2A R/B is a spent rocket body associated with Japan, launched on 2016-02-17 from TNSTA on the ASTRO-H launch. After 10 years in orbit, it continues to be tracked by global surveillance networks. It orbits in Low Earth Orbit (LEO) at altitudes between 390 km and 394 km with an inclination of 30.6°. It travels at approximately 27,638 km/h (7.68 km/s), completing one full orbit every 92 minutes — that’s roughly 15.58 orbits per day. Its near-circular orbit (eccentricity close to zero) means it maintains a very consistent altitude throughout each revolution. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is months to ~1 year. Spent rocket bodies like H-2A 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.

H-2A R/B orbits at an average altitude of 392 km in the lower reaches of Low Earth Orbit, where atmospheric drag is significant and orbital lifetimes are measured in months to a few years. This is the busiest corridor in space — home to crewed spacecraft, rapid-revisit imaging satellites and the densest part of the Starlink constellation. Within ±50 km of H-2A R/B’s average altitude, there are currently 1,307 active payloads and 81 tracked debris or rocket body fragments — notable neighbours include STARLINK-1008, STARLINK-1012, STARLINK-1020. This makes it one of the more crowded altitude bands, containing roughly 7.5% of all active satellites. With an inclination of 30.6°, H-2A R/B passes over latitudes between 30.6°N and 30.6°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. Japan operates approximately 190 active satellites in total, of which 7 share a similar altitude band with H-2A R/B.