EPSILON DEB

EPSILON DEB is a tracked piece of space debris attributed to Japan, launched on 2013-09-14 from Uchinoura, Japan on the SPRINT-A launch. After 13 years in orbit, it continues to be tracked by global surveillance networks. It orbits in Low Earth Orbit (LEO) at altitudes between 846 km and 1,114 km with an inclination of 29.7°. It travels at approximately 26,509 km/h (7.36 km/s), completing one full orbit every 105 minutes — that’s roughly 13.75 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~100–500 years. As orbital debris, EPSILON DEB poses a potential collision risk to operational satellites in nearby orbits and is continuously monitored by the U.S. Space Surveillance Network and other tracking systems.

EPSILON DEB orbits at an average altitude of 980 km in the upper LEO band, where atmospheric drag is negligible and objects can persist for centuries to millennia. This altitude is used by broadband constellations like OneWeb and by scientific missions requiring stable orbits far from the densest debris bands. Within ±50 km of EPSILON DEB’s average altitude, there are currently 281 active payloads and 946 tracked debris or rocket body fragments. With an inclination of 29.7°, EPSILON DEB passes over latitudes between 29.7°N and 29.7°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 189 active satellites in total, of which 2 share a similar altitude band with EPSILON DEB.