Space law is a complex system governing outer space activities which comprises international treaties, conventions, United Nations General Assembly resolutions, as well as rules and regulations of international organisations. This paper will lay the international legal framework of space law, examining key documents like the Outer Space Treaty (OST) of 1967. Beyond this legal framework, the paper explores the militarisation of outer space, scrutinizing the intersection between space law and the evolving military activities taking place in outer space.

The fundamental legal framework of space law is composed of five international treaties and five sets of principles governing outer space. In addition, the UN General Assembly (UNGA) resolutions and the UN Committee for Peaceful Uses of Outer Space (UNCOPUS) documents in outer space serve as subsidiary means for interpreting and applying these treaties and principles. Customary international law also constitutes a component of space law (Xinmin, 2014).

Commencing with the fundamental legal instrument often referred to as the “Magna Carta of space”, the 1967 Outer Space Treaty (OST) underpins the existing framework (Johnson-Freese & Burbach 2019). Pertinently, the OST mandates that parties utilise the Moon and other celestial bodies for peaceful purposes, with the term “peaceful purposes” being subject to varied interpretations due to the dual-use nature of space technology for both civil and military applications (Johnson-Freese & Burbach 2019). Moreover, the treaty establishes a prohibition of the placement of nuclear weapons or other weapons of mass destruction in orbit, on the Moon, or on other celestial bodies. Notably, the OST does not preclude the weaponisation of space but specifically prohibits testing or deploying weapons of mass destruction, except on the Moon and other solid bodies, where no state has demonstrated an inclination for such placement. This may go in hand with the fact that the treaty discourages claims of sovereignty over the Moon, mandates open access to space installations and vehicles to representatives of other states and imposes liability on states for damage caused by objects launched from their territory. Moreover, according to the treaty, all parties agree to conduct outer-space activities in accordance with international law.