This paper will analyze the legal aspects of alternative power systems in space. The initial question is the legal status and rights to ownership of space resources, including helium ‐ 3, solar energy and other resources, used in these power systems. It is suggested that, although existing space law does raise questions about ownership and use, the official American understanding of the extant space treaties will permit the actual exploitation of these resources for space ‐ and earth ‐ based needs. ©American Institute of Physics 1995