Thousands of pieces of debris orbit Earth, from tiny paint flecks to dead satellites. Even a small fragment can damage spacecraft because it travels at high speed. To reduce new debris, some missions plan to deorbit satellites at the end of their life. Engineers also track larger objects so active satellites can move out of the way. Cleaning up old debris is difficult because grabbing a fast moving object is risky. Space agencies discuss guidelines to keep orbits usable for the future.