ESA’s involvement in the International Space Station (ISS) is without a doubt one of the Agency’s most significant projects to this date. Whilst being an astronaut is a dream many space enthusiasts strive toward, as showcased by the number of applications for the Agency’s last astronaut selection, there is also a complex legal and political structure serving as the basis for continued cooperation on the ISS. The multi-level legal structure consists of the ISS Intergovernmental Agreement, Memoranda of Understandings, bilateral Implementing Arrangements, as well as non-legally binding sets of standards such as the Crew Code of Conduct (CCOC) for International Space Station Crews. ESA astronauts travelling to the ISS must adhere not only to ESA’s own personnel policy, but to various other provisions, flight rules and disciplinary requirements set forth by the aforementioned legal framework.

All European Partner States to the IGA are considered to constitute the ‘European Partner’ to the ISS cooperation, represented by ESA as Cooperating Agency. In this capacity, ESA not only liaises and concludes Memoranda of Understanding and Implementing Arrangements connected to the ISS, but also takes appropriate measures through its delegate bodies to make sure that the non-binding instruments, inter alia the COCC, are applicable to European astronauts. The European Partner retains jurisdiction and control over the European research facility, namely the Columbus laboratory, and utilises equipment and facilities of the ISS as defined by the exchange with the other Partners.

The ISS can be considered a truly successful example of international cooperation in outer space activities and the milestone for the Lunar Gateway project – an ambitious endeavour for an intergovernmental space station in lunar vicinity. So far, four out of the five Cooperating Agencies currently collaborating on the ISS project have committed to the project. In October 2020, ESA’s Director General signed a Memorandum of Understanding with NASA that builds on the existing legal framework to further collaboration on a human outpost placed in Moon orbit, which will promote the exploration and peaceful use of outer space. 

For NASA, the Gateway is part of its Artemis programme. It is paramount to however distinguish the aforementioned Memorandum of Understanding between ESA and NASA from the Artemis Accords, a set of principles in the form of a political commitment, presented by the US to other states. While some of its member states have undertaken this step, ESA is not a signatory of the Artemis Accords. This is however not necessary for the continuous cooperation, as outlined above, which will allow for joint exploration of the Lunar surface.