Outer Space Treaty
The Outer Space Treaty, formally the Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies, is a multilateral treaty that forms the basis of international space law. Negotiated and drafted under the auspices of the United Nations, it was opened for signature in the United States, the United Kingdom, and the Soviet Union on 27 January 1967, entering into force on 10 October 1967. As of February 2022, 112 countries are parties to the treaty—including all major spacefaring nations—and another 23 are signatories. The Outer Space Treaty was spurred by the development of intercontinental ballistic missiles in the 1950s, which could reach targets through outer space. The Soviet Union's launch of Sputnik, the first artificial satellite, in October 1957, followed by a subsequent arms race with the United States, hastened proposals to prohibit the use of outer space for military purposes.
