As satellites become smaller and smarter, they will become increasingly capable of sophisticated operations in orbit. One class of operations "autonomous proximity operations" would allow satellites to inspect other satellites, diagnose malfunctions and provide on-orbit servicing. Such satellites could also provide sophisticated surveillance in space and would make excellent anti-satellite weapons. The rapid development of satellites capable of conducting close maneuvers to one another, in-orbit, may increase tension "suggesting that now may be the time to consider "rules of the road" for such operations. The Defense Technology Area Plan (2000) called for "the development of micro-satellite vehicles with significant capability" including the ability to "conduct missions such as diagnostic inspection of malfunctioning satellites through autonomous guidance, rendezvous, and even docking techniques."1 These missions "generally referred to as autonomous proximity operations"are being pursued by NASA, DARPA and the Air Force, each of which intends to launch demonstrators in coming years Jeffrey Lewis is a Graduate Research Fellow at the Center for International Security Studies at Maryland.