Spacecraft Hazards

Defunct satellites, spent rocket stages, and fragments left in Earth orbit. Travelling at kilometres per second, even a small piece can destroy a working spacecraft, and collisions create more debris — a growing hazard in low Earth orbit.

Tiny natural particles — grains of comet and asteroid dust — moving at tens of kilometres per second. They erode surfaces and can puncture spacecraft; together with orbital debris they define the impact hazard for spacecraft.

The build-up of electric charge on a spacecraft as it moves through the space plasma, especially during geomagnetic storms. A sudden discharge can damage electronics — a leading cause of space-weather-related spacecraft anomalies.

Single oxygen atoms that dominate the thin atmosphere of low Earth orbit. Highly reactive, atomic oxygen slowly erodes exposed spacecraft materials, a design concern for anything operating for long periods in LEO.

The ionised gas that pervades near-Earth space, from the ionosphere out through the magnetosphere. Its density and energy govern spacecraft charging, radio propagation, and the behaviour of the radiation belts.