N-1 DEB

N-1 DEB is a tracked piece of space debris attributed to Japan, launched on 1978-02-16 from TNSTA on the ISS-b launch. With over 48 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 972 km and 1,284 km with an inclination of 69.2°. It travels at approximately 26,246 km/h (7.29 km/s), completing one full orbit every 108 minutes — that’s roughly 13.35 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~500–1,000 years. As orbital debris, N-1 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.

N-1 DEB orbits at an average altitude of 1,128 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 N-1 DEB’s average altitude, there are currently 285 active payloads and 353 tracked debris or rocket body fragments — notable neighbours include ONEWEB-0250, ONEWEB-0527, ONEWEB-0528. With an inclination of 69.2°, N-1 DEB passes over latitudes between 69.2°N and 69.2°S, covering most populated land masses in both hemispheres. This mid-inclination band balances global coverage with efficient launch energy requirements. Japan operates approximately 189 active satellites in total.