International Space Law

In one line

Outer space is free for exploration and use by all States and is not subject to national appropriation, the launching State bears international responsibility for national activities there including those of private companies, and it is absolutely liable for damage caused on the surface of the Earth or to aircraft in flight.

Where airspace stops

No treaty says. The Chicago Convention gives every State complete and exclusive sovereignty over the airspace above its territory in article 1, and the Outer Space Treaty says outer space is not subject to national appropriation in article II. Neither instrument says where the first ends and the second begins, and the question has been on the agenda of the Committee on the Peaceful Uses of Outer Space for decades without resolution.

The two positions.

The spatialist approach would fix a boundary by altitude, and the figure most often proposed is about 100 kilometres, sometimes called the Karman line, on the reasoning that above it aerodynamic flight is impossible and orbital motion begins.

The functionalist approach would ask what the object is doing rather than where it is, so that an object in orbit is governed by space law whatever its altitude and an aircraft by air law.

Why the question has not been settled. States that launch have no interest in a low boundary that would place more of their activity under a permissive regime they already enjoy, and States that are overflown have no interest in a high one. Practice has settled the matter functionally without agreement: nobody protests the passage of a satellite in orbit over their territory, and that acquiescence, in the terms of [Custom], is the nearest thing to an answer the law has.

The Outer Space Treaty, 1967

The Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies, and it is the constitution of the subject.

Article I, the freedom. The exploration and use of outer space, including the Moon and other celestial bodies, shall be carried out for the benefit and in the interests of all countries, irrespective of their degree of economic or scientific development, and shall be the province of all mankind. Outer space shall be free for exploration and use by all States without discrimination of any kind, on a basis of equality and in accordance with international law, and there shall be free access to all areas of celestial bodies. There shall be freedom of scientific investigation, and States shall facilitate and encourage international cooperation in it.

Province of all mankind is not the same phrase as common heritage of mankind. [The Common Heritage of Mankind] works the difference: province of all mankind states an interest and a purpose; common heritage of mankind, in article 136 of the Convention on the Law of the Sea and article 11 of the Moon Agreement, carries with it non-appropriation, a management institution and benefit-sharing. Confusing the two is a common examination error.