This article discusses the normative essence of the principle of non-appropriation in outer space as envisaged in Article II of the Outer Space Treaty, as well as its standing under customary international law. The analysis is structured with reference to the general public international law framework that governs the acquisition of territory by states, following the territorially based paradigm still prevalent in international law theory in stressing that the non-appropriation principle is indeed a norm of most increased significance within the corpus juris spatialis, i.e. the Grundnorm of international space law.
