Legal aspects of the use of (micro)reactors in space

Abstract This article aims to outline the legal framework for the current and future use of nuclear technology in spaceflight. Whereas binding international space law is enshrined in a system of treaties, foremost the Outer Space Treaty, this does not contain any particular provisions on the use of nuclear technologies. What we may call “nuclear law in space” is based on UN General Assembly Resolution 47/68 and the COPUOS/IAEA Safety Framework of 2009. Both documents require justification for the use of nuclear technology in space. For those uses which are justified, they contain requirements for safety and radiation protection which have thus far provided a good basis for the use of nuclear technology in space. With the advent of new nuclear technologies, however, such as modern (micro)reactors, they are considered to potentially require further development. There is no fundamental obstacle to such adjustments as long as the generic intentions of these regulations – prevention of damage to humans and to the Earth’s biosphere and prevention of contamination in outer space – are respected. Indeed, it may be assumed that novel nuclear technologies may warrant such protection even more effectively than existing ones.