Space trash, or space debris, refers to the collection of defunct satellites, spent rocket stages, and other fragments resulting from collisions or explosions in orbit around Earth. This debris poses a significant threat to active spacecraft and satellites due to the high velocities at which these objects travel, making even small pieces potentially dangerous.

The problem has grown as space activity has increased. There are thousands of pieces of debris larger than a few centimeters and many more smaller fragments. Efforts to mitigate space debris include designing satellites to deorbit at the end of their mission, actively removing debris using various technologies like nets or harpoons, and international agreements to promote best practices.

Managing space debris is crucial for maintaining the safety of space operations and ensuring the long-term sustainability of space activities.