Frans von der Dunk is Director of Space Law Research at the International Institute of Air and Space Law, Leiden University. He advises governments, international organisations, space agencies and companies on matters of space law and policy. He was awarded the Distinguished Service Award of the International Institute of Space Law (IISL) of the International Astronautical Federation (IAF) in Vancouver, in October 2004.Marcel Brus is Professor of Public International Law and Academic Director of the LL.M. Programme in International Law and the Law of International Organisations at the University of Groningen, The Netherlands.