Where the Final Frontier Begins: A Decades-Old Legal Controversy

Where does space begin? Although “space law” exists as a legal specialty, surprisingly, “space” does not have a legal definition. (Nelson, SpaceNews). On January 27th, 1967, six years after the first human traveled to space, the United Nations (UN) General Assembly adopted the Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies, otherwise known as the “Outer Space Treaty (OST).” (UN | Outer Space Treaty). This treaty, subsequently ratified by 100 member countries (including all major spacefaring nations), established core principles of shared, peaceful exploration of outer space for the benefit of all mankind. Id.

The treaty explicitly prohibits any nation from laying a claim of sovereignty to outer space or using space as a medium for weapon deployment and operation. Id. Additionally, under the OST, astronauts are regarded as the envoys of mankind (rather than solely representatives of their home country); member states are responsible for any space activities carried out by both governmental and non-governmental entities. Id. In the 53 years since the adoption of the OST, legal experts from various countries have attempted to solidify a defined border between “outer space” and “airspace,” while ultimately coming up short. (Nelson, SpaceNews). The considerable practical effect of such a lapse in legal doctrine is the Outer Space Treaty has no defined jurisdiction. Id.

Alternatively, aviation and “airspace” are governed by a combination of international organizations such as the International Civil Aviation Organization (ICAO) (an entity of the UN), and national organizations like the Federal Aviation Administration (FAA). In the 1944 Convention on International Civil Aviation, the UN adopted the principle that “every State has complete and exclusive sovereignty over the airspace above its territory.” (ICAO | Convention on International Civil Aviation) Therefore, unlike under the Outer Space Treaty, where a vehicle is not subject to any national sovereignty and enjoys navigational freedom, a vehicle traveling in a nation’s “airspace” is subject to that nation’s aviation regulations, as well as the nation’s right to deny access. Id.

Undoubtedly, the divergent positions on this issue will not be sustainable long-term. The conflicts between the international rules governing flight in both air space and outer space create substantial legal questions on safety, liability, and sovereignty. For example, without an objective definition of “outer space,” a spacecraft in low-earth orbit and a high-altitude military aircraft could be regulated interchangeably. The practical implications, both with regards to commercial space law and national security, are vast. For instance, a country wanting to avoid the “peaceful use” requirements of the Outer Space Treaty could use the unclear border to conduct high-altitude military missions that are essentially in outer space. By the same token, issues will likely arise in torts, contracts, tax, intellectual property, and privacy law.

While there is currently no agreement in international law on where the freedom of outer space begins, various experts and governmental bodies in the field of space law have attempted to draw the line. For example, a distance rule using a simple, fixed upper altitude boundary has been adopted by Australia, Denmark, Kazakhstan, and other countries. (Nelson, SpaceNews). In 2017, the chairman of the UN space law working group supported this approach “as an official position.” Id. Jonathan C. McDowell, an astrophysicist of the Harvard–Smithsonian Center, also recently revisited the Von Kármán Line as a solution, treating space as beginning at the point where it is impossible to fly an aircraft, at approximately 80 kilometers above mean sea level. Id. Similarly, McDowell suggests airspace would end at the lowest perigee of an orbiting satellite – perhaps as high as 160 kilometers, but potentially lower, depending on the orbit type. Id. An extreme example of boundary-drawing is the Bogota Declaration of 1976, in which a group of equatorial states laid claim to all geostationary orbit areas above them. Id. This claim, however, was met with widespread skepticism at the time and is not widely accepted. Id.

Conversely, the United States is one of few nations that finds defining a border unnecessary. Id. It’s likely the U.S. has taken this position to allow flexibility in both commercial and government aerospace operations. Officially, the U.S. State Department released a statement to the UN in 2001 reasoning “no legal or practical problems have arisen in the absence of such a definition.” Id. Even so, the U.S. National Oceanic and Atmospheric Administration (NOAA), an operator of the nation's env ironmental and meteorological satellites, has established their own definition, the Kármán Line (100 km or 62 miles above sea level). (Where is Space? | NOAA). They cite the world governing body for aeronautic and astronautic records, the Fédération Aéronautique Internationale (FAI), and many other organizations that use the Kármán Line as a way of determining when space flight has been achieved. Id. In contrast, the U.S. military, FAA, and NASA generally define the border of space 12 miles below the Kármán Line, at 50 miles above Earth's surface, due to the gradual loss of aerodynamic control above this point. Id. Pilots, mission specialists, and civilians who cross this boundary are officially deemed astronauts by these U.S. agencies. Id.

The key issue with the ongoing attempts to collectively define outer space stems from the rapid technological developments in aerospace engineering. The treaties governing air space and outer space were negotiated when (at least in the minds of the drafters) air and space travel were very distinct concepts. With the growth of suborbital fight technologies and the growing interest in space tourism, the functional distinction between air flight and spaceflight is less easily drawn. Additionally, the capabilities of satellites and aircraft will likely change over time, meaning the UN’s Von Kármán line and the orbiting line will have to change. However, even if the line is fixed at a given distance, such as 100 kilometers, technological advances may also render that border unsound.

Regardless, given the practical implications of an undefined boundary, the issue cannot be left open indefinitely. If a multilateral international agreement fails to come up with a definition before a legal dispute arises, an international arbitration body may have to. Therefore, while the United States may feel most flexible by operating without a firm definition of space, it is more beneficial long-term to participate in the process of creating one. Ultimately, given the rapidly evolving nature of aerospace technology, the best solution may be an ongoing process of establishing a fluid definition that can be reconsidered over time. Nevertheless, it’s time the UN, United States, and other spacefaring governmental entities take up this issue. They need to answer the question we all want to know—where does “the final frontier” begin?