Asked by: Tom Hampton, Townsville, Australia
Technically, spacecraft remain the property of the launching nation, but current international law is much more concerned with who is responsible for the damage and pollution at the crash site. When Skylab debris hit Australia in 1979, NASA allowed local residents to keep any pieces they found.
China lost control of Tiangong-1 in March 2016, so plans to deliberately de-orbit it were abandoned. Instead, its orbit decayed and most of the station burnt up during atmospheric re-entry on 2 April 2018 over the Pacific Ocean, north-west of Tahiti.
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