“Where Does the Sky End? Demarcating Airspace and Outer Space: Jurisdictional Challenges in International Law”

By Ishika Trivedi and Anubhav Nag (Himachal Pradesh National Law University)

Introduction

Imagine a privately owned spaceplane took off from State A and then, while crossing State B, a malfunction in the technicalities led to the fall of debris in State B, and then the plane finally landed in State C. The debris caused injuries to civilians in State B. In such a situation, which state will have jurisdiction? Where will airspace end and outer space start? At what point will sovereignty end and freedom start?   

This scenario very precisely highlights the legal vacuum that exists in our law- the jurisdictional challenges- and also emphasizes the real-life importance of delimitation. To delve into the answer of this conflict, we need to first understand what is airspace and what is outerspace?  

Concept of Airspace and Outer Space

To understand airspace and outer space, let us draw an analogy between two fields of international law- i.e. space and sea- since space law borrows certain concepts from maritime law. In 1609, Hugo Grotius gave the concept of Mare Liberum, which meant that the sea is open to all and is a common shared space and the property of none. Thereafter, a lot of disputes arose with technological advancements and other developments, which led John Seldon in 1645 to give the concept of Mare Clausum , which meant that coastal states have sovereignty over their adjacent waters, and it restricted foreign states to exercise rights. This debate led to the urgent need to establish boundaries like territorial sea, high sea and exclusive economic zone, which was done through United Nations Convention on the Law of the Sea (UNCLOS) of 1982. Similarly, it is necessary to establish boundaries in space, and these are called airspace and outer space. Airspace is the column of atmosphere over a state’s land, internal waters and territorial sea and over this the underlying state exercises complete sovereignty. No legal instrument has defined a precise boundary for this. Hence, air law is a realm of sovereignty. Outer space is the space which is beyond the airspace of every nation, and in this space, no state can claim sovereignty. It is commonly known as the global commons.  

Just like the conflict of mare clausum and mere liberum, in around 1918, two theories emerged regarding airspace, too. One was full freedom of air, of Paul Fauchille, the other was complete and exclusive sovereignty and just like the theory of mare clausum, the latter theory of airspace gained support as the principle of sovereignty grew stronger among states.   

(Add a few sentences saying something like -none of these theories have been recognised fundamentally. We will now look at the stance of international organizations regarding this- rn the Int framework is coming out of nowhere)

International Legal Framework:

The first legal framework that needs a mention while taking up a discussion about space law is the UN COPUOS established by UNGA in 1959 to govern the use and exploration of resources of outer space for the common benefit of mankind, it also attempts to establish peace, development and security of space. The UN has also established a body to ensure responsibility and accountability in space called United Nations Office for Outer Space Affairs (UNOOSA).  

The Outer Space Treaty, 1967, adopted by the UN General Assembly in 1966, governs the activities of states in using and exploring the resources in outer space and also includes the moon and other celestial bodies. India is a signatory to this convention.  

Article II of this treaty talks about the extent and sovereignty of outer space and states that ‘Outer space, including the moon and other celestial bodies, is not subject to national appropriation by claim of sovereignty, by means of use or occupation, or by any other means.’ 

Article I of the Convention on International Civil Aviation , commonly called the Chicago Convention, states that ‘contracting States recognize that every State has complete and exclusive sovereignty over the airspace above its territory.’ This is also recognized by the Convention Relating to the Regulation of Aerial Navigation, which is also known as the Paris Convention.   

Need for Delimitation and the Delimitation Debate:

With the advent of aircrafts that operate both within the atmosphere and extra-atmospheric, the absence of clear boundaries led to ambiguity and uncertainty. Looking back there never arose a need to delimit the space since the extraction and exploration of resources was confined only up to a certain height but now since the technology has advanced and there is always a new high reached in the space by different nations, there arose a need to define a boundary up to which a state can intervene in the space and to ensure that it does not trespass into another nations’ airspace. Protection of a nation’s airspace is necessary to ensure the safety and security of the nation.  

Another major factor which led to indispensable need to establish boundary is to determine the jurisdiction of a state. What laws are to be followed when an aircraft is in space? Which nation will have control over such aircraft? In case of a civil or criminal dispute, which state shall exercise jurisdiction? For all these questions to be answered, it was necessary to first determine the boundaries of space.   

Another major issue is the determination of liability for damages caused by private aircraft. Furthermore, it is needed to establish the sovereignty of a nation, particularly because outer space is governed by the principle of non-appropriation. Uncertainty is created in overflight rights, military surveillance, regulating commercial activities and remote sensing activities.   

Despite such an indispensable need and decades of debate, there has been no clear and precise international instrument. However, two approaches are generally followed:  

• Spatial approach: This is also known as the physical approach; it essentially means that there is a need to establish a physical boundary between airspace and outer space. It states that a physical fixed altitude limit is to be kept to separate the boundaries. Several proposals under this approach have been put forward, a few of them are-  

o Kármán Line: The most widely discussed boundary is the Kármán Line, located at approximately 100 kilometres above mean sea level. At this altitude, aerodynamic  

flight becomes impractical, and orbital mechanics govern movement.  

o Orbital approach: This places the border between airspace and outer space at the lowest altitude that an artificial Earth satellite can effectively execute a full round orbit around the planet.  

• Functionalist approach: This approach essentially means that there is no need for a physical boundary, and there is no need for one to exist. It asserts that the delimitation should depend on the kind of activities to be taken up in the space.  

Jurisdiction and Challenges:

The jurisdiction typically depends upon several factors like the launching state, the state of registry, and the nationality of the astronaut, among others. Commonly, under Article VIII of the Outer Space Treaty, a state retains control over its registered aircraft along with the personnel onboard and hence jurisdiction of the state of registry. According to the provisions of the  Convention on International Liability for Damage caused by Space Objects of 1972, and, in particular, its Article II, the launching state has absolute liability to compensate for the damages caused by its space objects on the surface of the Earth or to an aircraft in flight. On the other hand, according to Article III of the Liability Convention, if damages to a space object of one state-party are caused by a space object of another state-party in any location other than the surface of the Earth, the Launching State is only liable if such damages constitute fault of persons it is responsible for. Military and security jurisdiction in matters related to air defence systems and interception of hostile objects is a leading issue. Private companies conducting suborbital flights blur the line between aviation and space activities. Some States have unilaterally defined the boundary between airspace and outer space in their domestic laws, while others have avoided doing so. This lack of uniformity prevents the emergence of customary international law on the issue.  

Way Forward and Conclusion:

The delimitation issue is an urgent one, as there is growing congestion in this field. Among the existing approaches, the functional one seems more practicable as technological advancements blur rigid altitude distinctions. However, a hybrid model is preferable, adopting a presumptive boundary such as the Kármán line (~100 km) while retaining functional flexibility. Diplomatic efforts and consensus binding by international organizations should be done to maintain peace, order, responsibility and accountability. UN has in its policy brief titled ‘For All Humanity- the Future of Outer Space Governance’ made recommendations for a treaty for peace and humanity, space debris, traffic management, resource activities and inclusiveness. The legal status of this ambiguous region must be crystallized to support the next era of human exploration.