The spatial and functional delimitations of airspace and outer space: a practical economic question

• Department of Law

The International Law Working Group welcomes Damien Macedo (University of Cambridge) to present his research.

Abstract

Countries exert sovereignty in three dimensions: land and sea boundaries demarcate the latitudinal and longitudinal boundaries, while airspace sovereignty extends vertically. The problem that this paper addresses lies in determining how far this third dimension of sovereignty extends. Numerous authors have raised this question before, beginning a decade before the moon landing and the de facto end of the space race. Now that outer space is growing as a venue for commercial activity in the advent of a 'new space race' that promises significant economic gains for private actors, this paper argues that it is more important than ever to establish clear boundaries for the security and certainty of international economic law.

In airspace, the underlying state has full legal jurisdiction, while outer space is a res communis and may not be subject to state sovereignty. With no fixed international law definition of the boundary between outer space and airspace, nor any uniformly accepted methodology for finding this delimitation, we may be left with a legal vacuum that poses numerous questions for international law, and in particular for private actors in a burgeoning industry. Ambiguity in this context will engender demonstrable economic harms.

There are two different existing proposals for how the international legal community can delimit airspace and outer space: the functional method and the spatial method. The former method looks at what an object’s purpose is, why it was launched, and how it operates to determine whether it qualifies for the airspace or outer space legal regime. The latter method uses a set altitude above which sovereign airspace ends and outer space begins. Each of these comes with its own benefits and drawbacks, but this paper argues that the spatial method is the better solution to the problem of the undefined boundary.