Summary

Multilateral agreement signed and ratified between the U.S., U.S.S.R., and U.K. banning:

...placement of nuclear weapons or "weapons of mass destruction" in orbit around the Earth.

...installation of nuclear weapons or "weapons of mass destruction" on the moon, on any other celestial body, or in outer space

...use of the moon or any celestial body for military purposes, including weapons testing of any kind.

Ninty five nations have ratified the treaty. The treaty entered into force on October 10, 1963.

Narrative

The Outer Space Treaty, as it is known, was the second of the so-called "nonarmament" treaties; its concepts and some of its provisions were modeled on its predecessor, the Antarctic Treaty. Like that Treaty it sought to prevent "a new form of colonial competition" and the possible damage that self-seeking exploitation might cause.

In early 1957, even before the launching of Sputnik in October, developments in rocketry led the United States to propose international verification of the testing of space objects. The development of an inspection system for outer space was part of a Western proposal for partial disarmament put forward in August 1957. The Soviet Union, however, which was in the midst of testing its first ICBM and was about to orbit its first Earth satellite, did not accept these proposals.

Between 1959 and 1962 the Western powers made a series of proposals to bar the use of outer space for military purposes. Their successive plans for general and complete disarmament included provisions to ban the orbiting and stationing in outer space of weapons of mass destruction. Addressing the General Assembly on September 22, 1960, President Eisenhower proposed that the principles of the Antarctic Treaty be applied to outer space and celestial bodies.

Soviet plans for general and complete disarmament between 1960 and 1962 included provisions for ensuring the peaceful use of outer space. The Soviet Union, however, would not separate outer space from other disarmament issues, nor would it agree to restrict outer space to peaceful uses unless U.S. foreign bases at which short-range and medium-range missiles were stationed were eliminated also.

The Western powers declined to accept the Soviet approach; the linkage, they held, would upset the military balance and weaken the security of the West.

After the signing of the Limited Test Ban Treaty, the Soviet Unions position changed. It ceased to link an agreement on outer space with the question of foreign bases. On September 19, 1963, Foreign Minister Gromyko told the General Assembly that the Soviet Union wished to conclude an agreement banning the orbiting of objects carrying nuclear weapons. Ambassador Stevenson stated that the United States had no intention of orbiting weapons of mass destruction, installing them on celestial bodies or stationing them in outer space. The General Assembly unanimously adopted a resolution on October 17, 1963, welcoming the Soviet and U.S. statements and calling upon all states to refrain from introducing weapons of mass destruction into outer space.

The United States supported the resolution, despite the absence of any provisions for verification; the capabilities of its space-tracking systems, it was estimated, were adequate for detecting launchings and devices in orbit.

Seeking to sustain the momentum for arms control agreements, the United States in 1965 and 1966 pressed for a Treaty that would give further substance to the U.N. resolution.

On June 16, 1966, both the United States and the Soviet Union submitted draft treaties. The U.S. draft dealt only with celestial bodies; the Soviet draft covered the whole outer space environment. The United States accepted the Soviet position on the scope of the Treaty, and by September agreement had been reached in discussions at Geneva on most Treaty provisions. Differences on the few remaining issues -- chiefly involving access to facilities on celestial bodies, reporting on space activities, and the use of military equipment and personnel in space exploration -- were satisfactorily resolved in private consultations during the General Assembly session by December.

On the 19th of that month the General Assembly approved by acclamation a resolution commending the Treaty. It was opened for signature at Washington, London, and Moscow on January 27, 1967. On April 25 the Senate gave unanimous consent to its ratification, and the Treaty entered into force on October 10, 1967.

The substance of the arms control provisions is in Article IV. This article restricts activities in two ways:

First , it contains an undertaking not to place in orbit around the Earth, install on the moon or any other celestial body, or otherwise station in outer space, nuclear or any other weapons of mass destruction.

Second , it limits the use of the moon and other celestial bodies exclusively to peaceful purposes and expressly prohibits their use for establishing military bases, installation, or fortifications; testing weapons of any kind; or conducting military maneuvers.

After the Treaty entered into force, the United States and the Soviet Union collaborated in jointly planned and manned space enterprises.

Source: Department of State