This article evaluates the extent to which Melbin's (1978) ideal type of frontiers can be applied to a new frontier, outer space. Although outer space fits Melbin's model of frontiers in a number of ways, several deviations are also apparent. These deviations from the model are linked to a combination of four characteristics of outer space as a frontier: the highly technological nature of travel, dependence on Earth, government control, and the initially perceived limitlessness of space. This application leads to further specifications of Melbin's conceptualization of frontiers and provides the basis for speculation concerning the future of outer space as a frontier.