Tanja Masson-Zwaan

President Emerita

Tanja Masson-Zwaan is Asst. Professor and Deputy Director of the International Institute of Air and Space Law at Leiden University, and President Emerita of the International Institute of Space Law (IISL).

Tanja advises various bodies on space law issues, teaches and supervises students at Bachelors, Masters and PhD level, carries out research and publishes on a broad range of space law topics. She co-authored the 4th edition of ‘Introduction to Space Law’ (Kluwer 2019) and serves on the Board of Editors of Kluwer’s journal Air and Space Law.

Tanja is member of a team of experts advising the Dutch government on the implementation of the Netherlands Space Activities Act. She attends the annual sessions of the Legal Subcommittee of the UN Committee on the Peaceful Uses of Outer Space as an observer, and co-founded the Hague Space Resources Governance Working Group.


The Dutch Government appointed Tanja as an Arbitrator for space related disputes at the Permanent Court of Arbitration, and as a Member of the Space Learning Group of ICAO.

Memberships and Board Positions

Tanja is an elected member of various professional associations such as the International Academy of Astronautics( IAA), the Académie de l’Air et de l’Espace (AAE) and the International Law Association, including its Space Law Committee and the Netherlands’ Branch NVIR. She was a Member of the Founding Boards of the European Centre for Space Law (ECSL) and of Women in Aerospace-Europe. She serves as Advisor to Secure World Foundation (SWF) and is an Honorary Board Member of Space Generation Advisory Council (SGAC).


Tanja is a recipient of the Distinguished Service Award of the IISL (2001), the Social Sciences Award of the IAA (2008) and the IAF Distinguished Service Award (2015). She is a Member of Honour of the Netherlands Space Society (NVR).

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Nandasiri Jasentuliyana

President Emeritus

Nandasiri (Nandi) Jasentuliyana (also known as Jasenthu Liyana Nanadasiri de Silva) is a Sri Lankan lawyer. He was the Director of the United Nations Office for Outer Space Affairs and the Deputy Director-General, United Nations Office at Vienna. He was also the President of International Institute of Space Law; Executive Secretary of the UN Conference on Nuclear Energy and UN Conference on the Peaceful Uses of Outer Space.

Jasentuliyana had served as a Political Affairs Officer at Department of Political and Security Council Affairs, United Nations; Member Board of Trustees of the International Space University (ISU); Member Board of Trustees at International Academy of Astronautics (IAA); Member Bureau, International Astronautical Federation (IAF); Member Editorial Board of Journal of Space Policy, UK; Member Editorial Board, Journal of Space Law USA; Member, Board of Directors of the International Institute of Air and Space Law, Faculty of Law, University of Leiden and Programme Officer, Asia Foundation.

Educated at Richmond College, Galle, he holds advanced degrees in Law and International Relations from the Universities of Ceylon, London and McGill, and is an Attorney-at-Law. He holds diploma in Aerospace Law from McGill University and a diploma from the Academy of International and Comparative Law.

International Institute of Space Law

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