When did the Outer Space Treaty enter into force?
The Outer Space Treaty entered into force on the 10th of October 1967. It opened for signature in the United States, the United Kingdom, and the Soviet Union on the 27th of January 1967.
The Outer Space Treaty entered into force on the 10th of October 1967. It opened for signature in the United States, the United Kingdom, and the Soviet Union on the 27th of January 1967.
Article II of the Outer Space Treaty explicitly forbids any government from appropriating a celestial body such as the Moon or a planet. This prohibition applies whether by declaration, use, occupation, or any other means.
As of October 2025, 118 countries are parties to the Outer Space Treaty while another 20 have signed but not completed ratification. Multiple dates indicate the different days in which states submitted their signature or deposition.
The Outer Space Treaty was created because intercontinental ballistic missiles could now reach targets through outer space following the launch of Sputnik in October 1957. The United States and the Soviet Union entered an arms race that threatened to spill into the cosmos leading to U.N. resolutions prohibiting weapons of mass destruction.
Private U.S. companies lobbied the government which introduced the U.S. Commercial Space Launch Competitiveness Act of 2015 to legalize space mining despite the ambiguity of the original treaty. Similar national legislation to legalize the appropriation of extraterrestrial resources are now being introduced by other countries including Luxembourg, Japan, China, India, and Russia.