Space Law and Orbital Territory

The legal architecture of outer space rests on the Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies, known as the Outer Space Treaty (OST), opened for signature on January 27, 1967 and entered into force on October 10, 1967 after ratification by the United States, the Soviet Union, and the United Kingdom, its three original depositary governments. Article II declares that outer space, including the Moon and other celestial bodies, is "not subject to national appropriation by claim of sovereignty, by means of use or occupation, or by any other means," establishing space as a global commons akin to the high seas. Article IV bans placing nuclear weapons or other weapons of mass destruction in orbit or on celestial bodies and restricts the Moon and other bodies to peaceful purposes, while Article VI makes states internationally responsible for national space activities, including those of private companies operating under their jurisdiction, and requires authorization and continuing supervision of non-governmental actors. As of the mid-2020s the treaty had well over 110 states parties, including every major spacefaring nation, making it the single most consequential instrument in space law despite its brevity.