Liability Convention

The Convention on International Liability for Damage Caused by Space Objects, commonly called the Liability Convention, was opened for signature on 29 March 1972 and entered into force on 1 September 1972. It elaborates the liability principle first stated in Article VII of the 1967 Outer Space Treaty and is one of the five core UN space treaties negotiated through the Committee on the Peaceful Uses of Outer Space (COPUOS).

The treaty establishes two distinct liability standards:

• Absolute liability (Article II) applies when a space object causes damage on the surface of the Earth or to aircraft in flight. The launching state pays regardless of fault.
• Fault-based liability (Article III) applies when damage occurs in outer space to another state's space object or persons aboard it. The claimant must show fault.

A "launching state" is broadly defined (Article I) as a state that launches, procures the launch, or from whose territory or facility a space object is launched — meaning multiple states can be jointly and severally liable for a single mission. Claims are presented through diplomatic channels (Article IX), not domestic courts, and if not settled within one year either party may request a Claims Commission (Articles XIV–XX). Compensation is determined according to international law and principles of justice and equity (Article XII), aimed at restoring the claimant to the condition that would have existed had the damage not occurred.

The Convention's only formal invocation to date was by Canada following the 1978 crash of the Soviet nuclear-powered satellite Kosmos 954 in the Northwest Territories. Canada presented a claim of roughly CAD 6 million for cleanup costs; the USSR paid CAD 3 million in a 1981 settlement without formally acknowledging liability under the treaty.

Critics note that the Convention was designed for a state-centric era and fits awkwardly with the rise of commercial operators, mega-constellations, and orbital debris, where causation is hard to prove and the fault standard in orbit has never been tested.