Jack Wright Nelson* and David S. Schuman**
I. Introduction
“There’s a certain part of the Moon that everyone knows is the best. We have ice there—we have sunlight there. We want to get there first and claim that for America.” With these words, spoken at a U.S. Department of Transportation press conference on 5 August 2025, Acting NASA Administrator, Sean Duffy, attracted the attention of space lawyers worldwide. The concern? That any and all lunar “claims” appear to run counter to Article II of the Outer Space Treaty (OST). Article II states that “[o]uter space, including the [M]oon 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.” On its face, Article II presents a straightforward preclusion of lunar claims. But reading Acting Administrator Duffy’s comments alongside the rest of the OST exposes a fundamental tension within the Treaty itself—one that may transform the Moon into the “province of whoever gets there first,” despite treaty language proclaiming it the “province of all [hu]mankind.”
II. De Jure Prohibition and De Facto Permission
The distinction between what the OST formally prohibits and what it practically enables is the cause of this tension. While Article II sets out a de jure prohibition, provisions in the OST are de facto permissive of exclusive uses of parts of the lunar surface. First, Article VIII grants states “jurisdiction and control” over space objects and personnel “while in outer space or on a celestial body.” Second, Article XII acknowledges that states may establish “stations” and “installations” on the Moon. Third, Article XII permits the installing state to control access to these stations and installations through advance notice requirements. Finally—and perhaps most significantly—Article IX requires states to conduct lunar activities “with due regard to the corresponding interests of all other States Parties to the Treaty” and mandates international consultations before proceeding with activities that may cause “potentially harmful interference” with others’ operations.
In sum, the OST prohibits national appropriation of any part of the Moon but acknowledges infrastructure that necessarily occupies lunar surface area, and insulates that infrastructure from interference. The only way to reconcile the Treaty’s various provisions is to acknowledge that occupation of parts of the lunar surface does not—in and of itself—constitute appropriation under Article II. The United Nations has even adopted principles relevant to the use of nuclear reactors in space. The practical result? Once lunar infrastructure is in place, that infrastructure can occupy the relevant portion of the lunar surface.
III. Opening the Overton Window
It remains an open question how long such occupation could persist, without amounting to national appropriation. There is very limited practice on this point, other than to note that the hardware from the Apollo missions—including landers—has occupied parts of the lunar surface for more than fifty years. Let’s consider the immediate context for Acting Administrator Duffy’s announcement: plans to deploy a nuclear reactor on the Moon by 2030, targeting what he described as the “best” part of the moon, the resource-rich south polar region where water ice may lie in permanently shadowed craters. A 100-kilowatt nuclear reactor represents a significant infrastructure investment that would likely anchor a much larger facility complex. As Michelle Hanlon, Professor of Air and Space Law at the University of Mississippi, recently observed, nuclear reactors and other infrastructure create lasting influence, with the first-arriving state effectively drawing “a line on the lunar map.”
These plans do not suggest that the reactor—and the associated facilities, if they come to pass—are intended to be temporary. It may be that the long-term nature of the project motivated Acting Administrator Duffy’s choice of the word “claim.” However, it is unclear whether such territorial language reflects a lack of appreciation for the existing treaty framework, or signals a deliberate shift in U.S. space policy. Importantly, the NASA directive on the reactor itself could have captured a change in policy explicitly, but did not. The recent Executive Order, titled “Enabling Competition in the Commercial Space Industry,” while recognizing the OST in Section Five, is silent on this point.
Analysis of oral remarks, as opposed to formal policy documents, could be criticized as premature. Yet Acting Administrator Duffy’s comments show how easily casual language can impact carefully constructed legal principles. It is not uncommon for official language to presage shifts in policy. Whether the Trump Administration captures such language as formal policy in this case or adjusts it to align more closely with existing treaty language remains to be seen. On November 4, 2025, President Trump re-nominated Jared Isaacman to be NASA Administrator; he was then confirmed by the United States Senate on December 17. It remains to be seen whether NASA will follow Acting Administrator Duffy’s comments with formal policy, or pursue a more traditional view of property rights on the Moon. In any event, Acting Administrator Duffy’s choice of language remains significant, because it opens the Overton Window to explicit territorial thinking in international space law. The Overton Window is the range of ideas considered acceptable for public discussion at any given time. If senior officials of a leading space power begin speaking openly about claiming lunar territory, other nations may feel compelled to abandon multilateral frameworks in favor of more aggressive and fundamentally territorial strategies. The result could be the (further) fragmentation of international space law and the dismantling of Article II.
IV. Conclusion
One could argue that a “first-come, first-served” approach represents the best way to fully and efficiently develop the Moon. It certainly has been the applicable framework for much of human history on Earth, with all its injustices and detrimental effects. And there are good reasons to be cynical that human activity in outer space will be any different from previous human behavior: nations will pursue strategic advantages, establish presence where possible, and use the language of international law to legitimize their positions.
Such observations aside, international law has tended to have a moderating effect on human behavior. We think that is a good thing. Perhaps today’s challenge is best characterized as preserving the OST’s aspirational vision of space as humanity’s shared heritage while developing practical frameworks that acknowledge the realities of lunar development. This may require walking a careful path: creating clear rules for conduct around infrastructure without abandoning the principle that no nation can appropriate any part of the Moon. The alternative—allowing increased territorial rhetoric until Article II becomes meaningless—risks transforming the Moon from the “province of all [hu]mankind” into a patchwork of de facto national territories, secured not by law but by whoever gets there first.
*Jack is an Assistant Professor of Law at Thompson Rivers University. His teaching and research focus on air and space law, and more broadly on the intersections between law, science, and technology.
**David is retired from NASA’s Office of General Counsel at the Goddard Space Flight Center where he was lead counsel for the James Webb Space Telescope from the project’s inception through launch and operation. He recently represented the International Astronomical Union and National Space Society, respectively, at the Legal Subcommittee and General Meeting of the United Nations Committee on the Peaceful Uses of Outer Space. Views expressed here are personal and do not represent those of NASA, the U.S. Government, or other organizations.