COSMOS 397 DEB

COSMOS 397 DEB is a tracked piece of space debris attributed to Russia (CIS), launched on 1971-02-25 from Baikonur Cosmodrome, Kazakhstan on the I2P launch. After more than 55 years in orbit, it is one of the longest-surviving objects in the space catalogue. It orbits in Low Earth Orbit (LEO) at altitudes between 485 km and 894 km with an inclination of 65.3°. It travels at approximately 27,049 km/h (7.51 km/s), completing one full orbit every 99 minutes — that’s roughly 14.61 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~10–25 years. As orbital debris, COSMOS 397 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.

COSMOS 397 DEB orbits at an average altitude of 690 km in the mid-LEO band, where atmospheric drag is minimal but radiation exposure remains manageable. Objects at this altitude persist for decades to centuries, making debris mitigation critical. This regime is popular for remote sensing constellations and scientific instruments that need stable, long-duration orbits. Within ±50 km of COSMOS 397 DEB’s average altitude, there are currently 335 active payloads and 1,448 tracked debris or rocket body fragments — notable neighbours include TERRA, AQUA, ONEWEB-0179. With an inclination of 65.3°, COSMOS 397 DEB passes over latitudes between 65.3°N and 65.3°S, covering most populated land masses in both hemispheres. This mid-inclination band balances global coverage with efficient launch energy requirements. Russia (CIS) operates approximately 1,537 active satellites in total, of which 20 share a similar altitude band with COSMOS 397 DEB.