The Convention on International Liability for Damage Caused by Space Objects is an international treaty, or act, that establishes rules for state responsibility for space-related damage. It originated from negotiations by the Legal Subcommittee between 1963 and 1972, was agreed upon by the UN General Assembly in 1971 (Resolution 2777 (XXVI)), and entered into force on September 1, 1972. The Convention was created to elaborate on Article VII of the Outer Space Treaty of 1967 and solve the problem of ensuring prompt, full, and equitable compensation for victims of damage caused by space objects.
The mechanism of the Convention hinges on two types of liability based on where the damage occurs. A Launching State—defined in Article I as a state that launches, procures the launching, or from whose territory or facility a space object is launched—is held to absolute liability for damage caused on the surface of the Earth or to aircraft in flight (Article II). This means the claimant state does not need to prove fault. However, liability is based on fault for damage caused elsewhere than on the Earth's surface, such as in outer space, to another state's space object (Article III). When two or more states jointly launch a space object, they are held jointly and severally liable for any damage caused (Article V). The only exoneration from absolute liability is if the launching State proves gross negligence or intent to cause damage by the claimant State (Article VI). The Convention connects directly to the Outer Space Treaty of 1967. Since its entry into force, the core liability provisions have remained the same, with the only claim filed under the Convention being Canada's claim against the Soviet Union following the 1978 crash of the nuclear-powered satellite Kosmos 954.