Although legal principles to govern space were discussed as early as the mid-1950s, they were not formalized until the Outer Space Treaty (OST) 1967 was adopted and came into force. The OST establishes a number of principles affecting the placement of weapons in outer space. In particular it provides that “the Moon and other celestial bodies shall be used exclusively for peaceful purposes” and prohibits the testing of any types of weapons on such bodies. More generally the OST forbids the placement of nuclear weapons or other weapons of mass destruction in outer space. In addition there are a number of disarmament treaties and agreements emanating from the United Nations Office for Disarmament Affairs and the Conference on Disarmament that are relevant to weapons in space.
Although the disarmament provisions and international humanitarian laws place some restrictions on the use or manner of use of space weapons, none prohibit space weaponization. The absence of such prohibition is not due to many attempts over the years to prevent an arms race in space. Notable among these are Prevention of an Arms Race in Space Draft Treaty and the Prevention of the Placement of Weapons in Space Draft Treaty.
In considering the laws affecting space weapons a fundamental question that arises is what constitutes a weapon and does its placement in space breach the requirement that outer space be used exclusively for peaceful purposes? As an example, does a satellite used to control and direct an armed drone breach the peaceful use provision of the OST? There may be risks that without international norms governments and substate groups may acquire and use armed drones in ways that threaten regional stability, laws of war, and the role of domestic rule of law in decisions to use force.
Given their orbital velocity, any object in space could be a weapon with capability to destroy a satellite or other space object. There is also a growing population of dual-use satellites with military as well as civilian applications. These present great difficulty in arriving at a workable definition of a space weapon in the formulation of a generally acceptable treaty. In addition, there are divergent views of the meaning of peaceful use. Some, in particular the United States, consider the meaning to be “nonaggressive” rather than “nonmilitary.”
Chinese and US Kinetic Energy Space Weapons and Arms Control
