Dr. Tanja Masson-Zwaan is Assistant Professor and Deputy Director of the International Institute of Air and Space Law at Leiden University, The Netherlands, and a leading expert in space law. She advises governments and international organisations, teaches worldwide, and co-authored the widely used textbook ‘Introduction to Space Law’. She is President Emerita of the International Institute of Space Law, and serves on various international boards related to space governance and sustainability, including Open Lunar Foundation and the Space Sustainability Rating. She chairs the Board of Editors of Kluwer’s journal Air and Space Law. In recognition of her work, she was appointed Officer in the Order of Orange-Nassau.