According to a February 14, 2014 story in NASASpaceFlight.com, Mike Gold, Director of D.C. Operations at Bigelow Aerospace, revealed a concept to ensuring lunar property rights that would seem to be consistent with the Outer Space Treaty, which prohibits the establishment of national sovereignty on other worlds.
“In an effort to move forward the discussion on property rights, Bigelow is seeking clarification from the Federal Aviation Administration’s Office of Commercial Space Transportation (AST) on whether launching a Moon habitat allows them to have a zone of operation in which other persons are prevented from entering.”
The theory is that establishing such an exclusion zone, whether it would be for a lunar base or a robotic probe, would be covered under Article IX of the Outer Space Treaty which states, “In the exploration and use of outer space, including the Moon and other celestial bodies, States Parties to the Treaty shall be guided by the principle of co-operation and mutual assistance and shall conduct all their activities in outer space, including the Moon and other celestial bodies, with due regard to the corresponding interests of all other States Parties to the Treaty. States Parties to the Treaty shall pursue studies of outer space, including the Moon and other celestial bodies, and conduct exploration of them so as to avoid their harmful contamination and also adverse changes in the environment of the Earth resulting from the introduction of extraterrestrial matter and, where necessary, shall adopt appropriate measures for this purpose.”
Of course Bigelow is contemplating a privately run lunar base, likely engaged in mining operations. But that would seem to be covered by Article VI which discusses non governmental entities (such as Bigelow) and the responsibilities of state parties to ensure they are in compliance with the treaty.
There are few if any enforcement mechanisms in the treaty if a dispute were to arise, say if China were to object to an exclusion zone being set up around a private lunar mining base. This suggests that a government presence, even in the form of NASA researchers, would be required to emphasize U.S. government sanction of an exclusion zone.
Private property rights on the moon and other celestial bodies are seen as crucial to enable commercial development in space.