Sky's the limit?

Land ownership in Scotland traces back to Roman law, where the ad coelum doctrine suggested that the owner of a property had rights “all the way to Heaven and all the way to Hell”. 

Whilst this may imply that a property owner has all the rights to the airspace above it, the concept is more nuanced. Property owners have the right to peaceful enjoyment of their property, including their airspace, and entering another’s airspace through signs, wires, or cranes without permission can be trespassing. Furthermore, specific regulations apply to certain sectors – for example, drone operators should not fly their drones within 50m of people or property without their consent. To do so may be considered a violation of Civil Aviation Authority (“CAA”) regulations, alongside constituting a breach of the right to peaceful enjoyment of property or even trespassing.

Yet these rights and prohibitions are often qualified. Aircraft have the right to fly over land at a reasonable height, subject to certain restrictions and regulations. Moreover, planning regulations may limit the height of tall structures to avoid interfering with the rights of neighbouring landowners. Additionally, it is clear from Bernstein v Skyviews & General Ltd [1978] 1 QB 479 (an unsuccessful damages claim for trespassing in airspace) that rights in airspace extend only up to a height necessary for ordinary use and enjoyment of land. Ownership does not extend to the “Heavens”.

Who “owns” the airspace above your property?

Under the Chicago Convention on International Civil Aviation 1944, which has been ratified by 193 countries, including the UK, each state has exclusive sovereignty over the airspace above its territory and is responsible for regulating air traffic within that airspace. Defining territorial extent is important for this reason, alongside many other airspace related reasons, including the levying of charges and taxes, and implementing national security measures. However, there is no international agreement on the exact boundaries of a state’s airspace.

Horizontal airspace generally aligns with the state’s territorial waters, extending 12 nautical miles (22.2km) from its baseline. However, the precise boundaries may vary depending on several factors such as the state’s geographical location, historical claims, international agreements, and specific circumstances.

Vertical limits refer to the altitude above the mean sea level that a state controls. This limit determines the extent of a state’s control over its ability to regulate and control air traffic, conduct surveillance, and enforce national security measures. Additionally, the vertical limit has implications for international air travel, as it determines the extent to which a state can restrict or regulate the overflight of its territory by foreign aircraft. Most countries claim sovereignty over the airspace up to a certain altitude above their territory, with the altitude limit varying depending on the country and the purpose of the airspace regulation.

In the UK, the CAA regulates civil aviation within legal and policy frameworks set out by Parliament and the Secretary of State. Airspace is divided into different classes based on altitude limits and regulations. Controlled airspace is designated airspace where air traffic control services are provided, while uncontrolled airspace has no air traffic control. The highest level of UK airspace is class C, extending from FL (flight level) 195 to FL 660 (i.e. from 19,500 up to 66,000 feet).

Elsewhere specific limits can vary depending on the country and the type of airspace involved, such as controlled airspace, uncontrolled airspace, or special use airspace. The process for defining airspace boundaries may involve coordination and negotiations with neighbouring countries in cases where the respective airspace overlaps or borders other countries’ airspace. Furthermore, national laws and regulations may play a significant role in determining a state’s airspace boundaries. For instance, in the United States, the Federal Aviation Administration (FAA) has established regulations that govern the use of airspace within the country. These regulations include restrictions on flying over certain areas, such as military installations and national parks. Overall, determining the boundaries of a country’s airspace is a complex process that involves a combination of international agreements and conventions, as well as national laws and regulations.

Unauthorised use of airspace

When an airplane or other airborne vehicle enters a country’s airspace without permission, it could be deemed a violation of that country’s sovereignty and territorial integrity, potentially creating disruptions to air traffic control and posing a risk of collisions. Moreover, it could be perceived as a threat to national security. Hence, most nations have established strict regulations that govern and monitor the entry of airborne vehicles. These regulations play a vital role in protecting national security and guaranteeing the safe operation of authorised vehicles.

The Royal Air Force is responsible for intercepting and identifying unauthorised vehicles in UK airspace. International law prohibits the use of force against civilian aircraft unless the aircraft poses an imminent threat to human life. Therefore, before using force, the country must take all necessary steps to identify the vehicle and communicate with the pilot to attempt to resolve the situation peacefully. The use of force must be a last resort when all other means of resolving the situation are exhausted. Similarly, the use of force against military or government aircraft is subject to the principles of proportionality and necessity.

An instance of an unauthorised plane occurred in December 2020 when a small airplane entered restricted airspace around London without authorisation, prompting the RAF to deploy fighter jets to intercept the plane. The pilot did not respond to attempts to contact, raising concerns, and two Typhoon jets were launched from RAF Coningsby, intercepted the aircraft and escorted it to Stansted Airport where it landed safely. This highlights the importance of having regulations and protocols in place to address potential security threats in a country’s airspace.

The boundary between airspace and outer space

Most countries claim sovereignty of their airspace up to a certain altitude, but the transition between airspace and outer space is not universally defined. The Kármán line, at an altitude of 100km (62 miles) above sea level, is the most widely used definition, but it is not officially recognised by the United Nations. While NASA defines the US boundary of space as 50 miles (80km), the UK and Russia adopt 62 miles (100 km) and proposed this for international recognition.

The emergence of private space exploration and tourism has highlighted the need to define the boundary between airspace and outer space. Different definitions of outer space can arise depending on the context. For instance, NASA and the UK Space Agency have differing criteria for defining an astronaut, based on their respective definitions of outer space. This discrepancy can cause confusion and complications in international cooperation and regulation of space activities, and has led to various interpretations and disputes regarding the legal status of objects in space and the rights and responsibilities of space-faring nations.

Who “owns” space?

Under international law, outer space is considered the “common heritage of mankind” and cannot be claimed by any one person or nation as their territory. The Outer Space Treaty of 1967 prohibits any country from asserting sovereignty over any celestial body, including the moon, and ensures that space is free for exploration and use by all nations.

However, as both the human population and the demand for resources grow, the availability of resources becomes increasingly limited and exhaustible. This has led to the search for alternative sources beyond the Earth’s surface, including the ocean floor and outer space. As previously mentioned, there is no clear definition of what constitutes “outer space”, and this ambiguity has become more significant in recent years, following a shift towards commercial space activities. Private companies have begun to explore space, seeking to exploit and “own” its resources.

While the Outer Space Treaty prohibits national appropriation of celestial bodies, it is unclear whether private entities are also prohibited from claiming ownership over the resources that they extract. This has led to a debate about how to regulate private space exploration and resource exploitation, and whether new international agreements are needed to clarify the legal framework for these activities. Some countries, such as the United States, have taken steps to encourage private space exploration and development, including the 2015 Commercial Space Launch Competitiveness Act. This Act allows US citizens to engage in the commercial exploration and recovery of space resources, which are defined as any non-living resources extracted from asteroids, the moon, or other celestial bodies.

The issue of private ownership and exploitation of space resources is likely to be the subject of ongoing debate and discussion among international organisations and governments in the coming years. In 2020, the UK signed the Artemis Accords, a set of principles proposed by the United States for the exploration and use of outer space, which include responsible extraction and use of space resources and the preservation of heritage sites and artefacts in outer space. However, some experts and organisations have raised concerns that the Accords may not be compatible with existing international space law and may prioritise the interests of spacefaring nations over the wider international community.

Currently, there is no consensus. Russia and other countries have proposed an international agreement to address the issue of space resource ownership and exploitation, but no such agreement has been reached yet. The issue of private ownership and exploitation of space resources is likely to be a subject of ongoing discussion and debate among international organisations and governments in the years to come.

“NewSpace” Space tourism

Asteroid mining is an industry within “NewSpace”, the emerging private space industry that is distinct from traditional government run space programmes. The NewSpace industry also encompasses other activities including space tourism, satellite operations, and more. This rapidly evolving sector is likely to play an increasingly important role in coming years. Since the Ansari X Prize in 2004, demonstrating the feasibility of commercial spaceflight, interest has been sparked in a new era of space tourism. This raises legal questions about licensing and safety oversight, liability and insurance implications, and passenger rights as regards consent, privacy etc. Leading companies in this field include Virgin Galactic and Blue Origin, both of which have completed successful projects.

As long as suborbital flights take off and land in the same state, that state’s national law will apply. The US and the UK have developed specific rules for suborbital flights. The US grants power for regulation and licensing to the Federal Aviation Administration’s Office of Commercial Space Transportation, while the UK’s CAA is responsible for licensing suborbital flights.

When a flight involves more countries, international law will apply, but it is uncertain whether this would be aviation law or space law.

The legal status of suborbital flights remains uncertain due to their position at the boundary between the Earth’s atmosphere and outer space, and this leaves them within the remit of both air law and space law regulations. Initially marketed for space tourism, suborbital flights have gained traction in recent years as a viable means of launching small satellites into space, leading to the emergence of new companies. For example, Virgin Orbit used a modified Boeing 747 to launch small satellites into space, further blurring the line between air law and space law regulation. The system launched from an altitude of roughly 35,000 feet, within the Earth’s atmosphere. However, its payload was designed to reach orbit, which is typically governed by space law. As technology and business models for suborbital flights continue to evolve, the legal status of these flights will remain a subject of ongoing discussion.

Satellites

While it is true that the Outer Space Treaty prohibits national appropriation of outer space and celestial bodies, it does not prohibit the ownership of artificial objects such as satellites. Countries and private companies can claim ownership and use of objects that they launch into space. Satellites may also be “owned” on a de facto level by obtaining the right to use the specific radio frequencies that are used to communicate with the satellite. To obtain this right, one must go through the frequency allocation process established by the International Telecommunication Union (“ITU”). The ITU allocates frequencies to different countries and organisations for use in satellite communications, and satellite owners must comply with international regulations and standards to ensure the safe and responsible use of the radio spectrum.

Small satellites are one of the best examples of new space activities. Scotland has emerged as a prominent player in the global satellite industry, producing more satellites than any other location outside California. This can be attributed to its well established aerospace sector and advantageous geographic location. Local manufacturers such as AAC Clyde Space have been instrumental in this growth. Additionally, with companies like Spire Global now choosing to design, build, and test their satellites in Scotland, it is rapidly becoming a key hub for the satellite industry.

Small satellites are considered space objects, and as such, states have rights and obligations regarding them. As per article VI of the Outer Space Treaty, state responsibility applies to any space activity that can be linked to a certain state or nationality. However, national space laws may also provide liability arrangements related to small satellites, and some jurisdictions may mandate third party liability insurance as a requirement for launching activities.

The Outer Space Act 1986 and the Space Industry Act 2018 are the principal instruments regulating activities carried out in the UK. Any individual or organisation that seeks to engage in such activities must first obtain a licence. Under s 34 of the 2018 Act, operators have strict liability for injury or damage caused by their activities, and by s 36 anyone conducting spaceflight activities must indemnify the Government or a listed person or body against any claims for loss or damage resulting from those activities, subject to limits applied pursuant to s 12(2). However, regs 218 and 219 of the Space Industry Regulations 2021 exempt certain persons from benefitting from strict liability and describe situations in which the limitations on indemnification may be disapplied. There are also requirements relating to insurance, principally in the licensing regime referred to in the 1986 Act and s 38 of the 2018 Act.

Search for clarity

With the increasing commercialisation of space and growth of new industries, there is a need for ongoing international cooperation and collaboration to address these complex issues and ensure that the use and ownership of airspace and outer space are managed in a way that promotes safety, security, and sustainability for all. For those operating in the sector, obtaining a clear picture of rights, responsibilities and likely upcoming changes in regulation is key.