Space debris is any human-made object in orbit that no longer serves a useful function. From dead satellites and spent rocket stages to paint flakes and coolant droplets, the debris population is large, growing, and consequential for every active operator.
Space debris is any human-made object in orbit that no longer serves a useful function. From dead satellites and spent rocket stages to paint flakes and coolant droplets, the debris population is large, growing, and consequential for every active operator.
The three tiers represent very different operational realities. Objects above 10 cm are individually tracked and avoidance maneuvers are possible. Objects 1–10 cm are too small to track individually but large enough to be mission-ending on impact. Objects below 1 cm are statistically modelled — shielding is the only mitigation.
In LEO, typical collision velocities are 7–15 km/s — up to 40× the speed of sound. At those speeds, kinetic energy scales with velocity squared.
Three events account for a disproportionate share of the current tracked debris catalog.
The US Space Surveillance Network (SSN) uses a global network of radar and optical sensors to maintain the public catalog.
In Orbital Radar, debris objects appear in the catalog with the same tracking data as active satellites — because operationally, the distinction only matters until the moment of impact. Conjunction warnings, TLE age, and altitude band all matter as much for debris as for active objects.