With the recent cancellation of the NASA Constellation program, there has been an apparent shift of focus from manned missions undertaken by a single nation to that of multilateral international cooperation. Thus, it is likely that a future manned mission to Mars will be undertaken by a consortium of international partners, with each nation contributing a specific segment of the project. In order to prepare for such an endeavor, a comprehensive framework of ground and space-based tests must be implemented, both for the purpose of training and for the validation of systems and operational procedures. A comprehensive survey of 50 analog studies was undertaken, selected from the topics of psychology, physiology, robotics, extra-vehicular activities, gravity simulation, life support systems, space architecture and integrated approaches. Critical analog studies have been identified as essential to the preparation of a future manned mission to Mars and these have been organized into a series of discrete, progressive steps. Using this selection of analog studies, a comprehensive analog roadmap has been created, aimed at providing policy makers and space agencies with recommendations for the implementation of a high fidelity analog study program with the end goal of preparing for an international mission to Mars. Particular emphasis has been placed on the international aspects of future manned missions and as a result, the analog roadmap is presented within a framework of multi-national collaboration. In addition, the commercialization aspects of future analog studies have been investigated, with emphasis on possibilities for commercial spin-offs as well as the prospect of offering analog sites as a commercial service. Finally, considerations regarding legal, ethical, and policy issues have been incorporated into the implementation of specific analog studies.