What treaty is the main legal framework for ISS partner nations?

The Space Station Intergovernmental Agreement is the main legal framework for ISS partner nations. Usually called the IGA, it sets the governmental foundation for cooperation on the station’s design, development, operation, and use.

The agreement was signed on January 28, 1998, by the United States, Russia, Japan, Canada, and participating European Space Agency member states. It established how partners would share responsibilities, rights, resources, and station components while maintaining the ISS as a peaceful civil project.

The IGA also addresses practical legal issues that arise when many nations operate one orbiting complex. These include jurisdiction and control, criminal matters, intellectual property, liability, and the responsibilities of the participating agencies. NASA and its partners implement the broader agreement through agency-level memoranda and detailed arrangements.

The Outer Space Treaty remains a foundational treaty for international space law, but it is not the ISS-specific partnership agreement. The Moon Agreement and Artemis Accords concern broader lunar or exploration frameworks, not the station’s central legal structure.