Fast forward 500 years: Humans have founded research colonies on the Moon and Mars, scientists are working on how to land on Jupiter, and the dream of reaching Saturn is on the table. While this expansive vision of space progress is exciting, one needs to look no further than our dear planet Earth to realize that the modern international legal regime is not yet equipped to handle future space exploration. Since the rate and direction of space sector development remain uncertain, it is critical to examine policy holes in the current legal regime and develop preliminary solutions.
Instead of setting up camp on more distant celestial bodies, some theorists envision a future with city-sized orbiting bases that could remain in low Earth orbit, approximately 1,000 miles above the planet’s surface. Such city-sized bases, as depicted in popular media like the Interstellar movie, are often envisioned as donut-shaped vessels capable of accommodating all components of a modern economy and city, sustaining thousands of people. Further, while initial orbiting cities may require consistent resupply missions from Earth, any realistic plan ought to strive for long-run self-sufficiency.
Indeed, these stations would likely contain everything required to sustain a functioning society, including farmland, waste management systems, doctors, lawyers, schools, jails, hair salons, a monetary system, and the means to conduct any necessary repairs or routine maintenance. To sustain a population for generations, reproduction would have to be possible, a problem eased by the ship’s constant rotation, which would create artificial gravity, a critical condition for successful gestation and birth.
While achieving this self-sustaining reality is a problem for engineers and scientists, even if a city population were to live, reproduce, and die autonomously on an orbiting station, one critical question remains: Who should govern?
As defined by the United Nations’ 1967 Outer Space Treaty, any space object remains under the jurisdiction of the terrestrial state that launched it. In this document and subsequent UN space treaties, space is treated as a global commons, yet the physical structures built and launched into orbit are legally tethered to terrestrial authority. More recently, the International Space Station (ISS), operational since 2000, is managed under a joint-ownership framework, where each international partner has jurisdiction over the portion they developed—take Japan’s experiment module or the European Space Agency’s Columbus Research Laboratory, for example—and is entitled to utilization rights for the other sections of the station.
While the above system of state authority over domestically developed space assets works efficiently in the modern era, some key assumptions grounding this model break down in the context of a future self-sustaining city-orbiter. For one, the Outer Space Treaty was written at a time when space habitation was still speculative, and the ISS Intergovernmental Agreement governs a station with normal crew sizes of seven and usual mission durations of about six months. In addition, modern astronauts are selected, trained by, and eventually return to their home country, making them naturally deeply connected to Earth’s geopolitical order. These assumptions quickly fail when considering a self-sustaining station on which thousands of passengers would be born and would die, having lived their entire lifetime there. Thus, instead of the modern system of terrestrial government control, if a self-sustaining orbiting city station is achieved, the people of that station should be independently sovereign and not tied to the international governing structure.
While calling for a new sovereign people seems radical on the surface, the rationale for this view is predicated on three intuitive assumptions: Enforcement from a terrestrial body would be nearly impossible; the culture and people of the city-station would be unrecognizable compared to those on Earth; and efficient decision-making would be necessary to keep the station alive. Following the logic of these assumptions, the natural conclusion is that it is most practical for people who can survive the absence of terrestrial help to govern themselves accordingly.
First, given a self-sustaining orbiting city, consistent trade with Earth or any other form of contact (except mutually beneficial collision prevention) would be purely elective for the orbiting city. It is also unlikely that station inhabitants would have Earth-tied assets after multiple generations on the station. Thus, absent the option to use missile technology to attack the orbiting city directly, terrestrial states or organizations would have limited leverage to sway in-orbit decision-making toward a policy the station deemed unfavorable. Even the countries that helped build the station will have to accept that any such arrangements made during the station’s development are effectively void after multiple generations.
Arguably more important than the coercive power that terrestrial states might attempt to yield is the willingness of station residents to be politically ruled by these states. After generations, normal genetic variation combined with lifestyle differences will yield a genetically unique population in the closed-system station. Moreover, increased exposure to radiation will lead to additional divergence from terrestrial humans. As seen from NASA’s comparison of astronaut Scott Kelly to his on-Earth twin brother after one year on the ISS, differences in gene expression, the gut microbiome, protein pathways, and more arise after only a short time in space.
In addition to biological changes, after living and reproducing in a unique environment with different challenges, living conditions, and hierarchies, the station’s population will likely develop a distinct culture. As time progresses, the difference between the composition and customs of the station’s first inhabitants and its current residents will only grow, making the perceived legitimacy of the terrestrial government ever more tenuous.
Finally, from a pragmatic view, the space domain is exceptionally unforgiving. In the event of an expected oxygen or food shortage, necessary repairs, or an increased risk of radiation, effective decision-making and on-station policy implementation will be crucial to sustaining the orbiting city. Furthermore, such problems are likely to recur, making them easier to solve as the population gains experience and divides into specialized expertise. Not only does this process not require oversight from a terrestrial body that knows less about the situation, but the inhabitants may also be practically worse off if they rely on slow communication for clearance in an emergency. Of course, things like ground-based monitoring and tracking data might be very useful in disaster mitigation. Still, this level of data sharing is consistent with how sovereign states share data today. As such, there is no clear pragmatic advantage to having terrestrial-based leadership.
Tying the three assumptions together, the argument for a sovereign orbiting city is satisfactory when considering its ability to assert its sovereignty, the will of its population, and the pragmatic utility of independence in decision-making. While this result is intuitive, its significance should not be underestimated. Although the last UN space-focused treaty entered into force over 40 years ago in 1984, the space sector has continued to scale and progress exponentially, a trend fueled by ever-falling launch costs and $393 billion invested across over 2,000 space companies. Even if it is unclear whether sustained human habitation will be achieved within the next few hundred years, rapid development in the space sector is imminent. When a technology becomes feasible, we face rapid changes without much warning, which necessitates the creation of new policy ahead of time. For example, in 2019, there were only about 2,000 satellites in orbit, but by 2023, the number increased to over 9,000, sparking an American effort to reevaluate its space debris mitigation policy—a difficult task due to limited prior research.
Under the constant uncertainty of what the space sector could yield, it is paramount that our leaders consider space law edge cases and prepare modifiable policies for use when a breakthrough technology is reached. Even if an orbital habitat exists in fiction today, exploring its legal implications ensures that, when science catches up to our imagination, our institutions will not be decades behind.