Foreword

This thesis concluded my Master's degree in Law at the University of Oslo, where it was submitted in May 2026. Apart from some light editorial changes, the text appears here as it was originally submitted.

The high seas and outer space are both areas beyond national jurisdiction, each subject to a foundational prohibition on national appropriation and each governed by its own legal regime. To date, however, these two bodies of law have developed largely in isolation from one another. Yet they are physically connected by an increasingly routine practice: the controlled and uncontrolled reentry of space objects into the ocean. With the growth of commercial spaceflight and satellite mega-constellations, splashdown disposal in remote ocean areas, most famously the "spacecraft cemetery" surrounding Point Nemo, has become the space industry's default end-of-life solution, largely unexamined by international environmental law.

The topic of this thesis is the obligations that international law imposes on launching and responsible States with respect to the environmental regulation of such reentries. In particular, I consider whether the Agreement on Marine Biological Diversity of Areas Beyond National Jurisdiction (the BBNJ Agreement), which entered into force on 17 January 2026, closes the normative gap between international space law and the law of the sea, with particular attention to its environmental impact assessment framework, read alongside UNCLOS, the Outer Space Treaty corpus, and customary international law.

I am sincerely and wholeheartedly grateful to my supervisor, Professor Alla Pozdnakova, whose excellent guidance, generous support, and flexibility made this research both possible and a genuine pleasure. Her insight and encouragement have shaped not only this thesis, but the direction of my research beyond it.

Finally, thank you to my partner Maximilian for his unwavering support and patience throughout this project, to my son Leander, who provided a unique and humorous toddler’s perspective on these topics, and to the newest member of our family, Alastair, whose timely arrival provided excellent motivation to finish this thesis early.

Tromsø, 2 July 2026

Reagan Aylmer