SCOUT X-4 DEB

SCOUT X-4 DEB is a tracked piece of space debris attributed to United States, launched on 1965-11-19 from Wallops Flight Facility / MARS, United States on the Solar Explorer A launch. After more than 61 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 627 km and 743 km with an inclination of 59.7°. It travels at approximately 27,058 km/h (7.52 km/s), completing one full orbit every 98 minutes — that’s roughly 14.63 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~10–25 years. As orbital debris, SCOUT X-4 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.

SCOUT X-4 DEB orbits at an average altitude of 685 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 SCOUT X-4 DEB’s average altitude, there are currently 341 active payloads and 1,401 tracked debris or rocket body fragments — notable neighbours include TERRA, AQUA, ONEWEB-0179. With an inclination of 59.7°, SCOUT X-4 DEB passes over latitudes between 59.7°N and 59.7°S, covering most populated land masses in both hemispheres. This mid-inclination band balances global coverage with efficient launch energy requirements. United States operates approximately 13,196 active satellites in total, of which 98 share a similar altitude band with SCOUT X-4 DEB.