The NASA Authorization Act of 2005 articulated a new strategy for the nation's space program by specifically stating that “The Administrator shall establish a program to develop a sustained human presence on the Moon, including a robust precursor program, to promote exploration, science, commerce, and United States preeminence in space, and as a stepping-stone to future exploration of Mars and other destinations.” This vision calls for a progressive expansion of human capabilities beyond low-Earth orbit (LEO), seeking to answer profound scientific and philosophical questions while responding to discoveries along the way. In addition, the strategy calls for developing the revolutionary new technologies and capabilities that are required for the future human exploration of the solar system. This strategy represents a bold new step. In January 2004, NASA established the Exploration Systems Mission Directorate (ESMD) to lead the development of new exploration systems to accomplish the task of implementing the strategy. To determine the best exploration architecture and strategy to implement these many changes, the Exploration Systems Architecture Study (ESAS) was conducted in 2005. This study provided the top-level architectural foundation and driving requirements for the lunar transportation systems. In 2006 through mid-2007, NASA conducted the Lunar Architecture Team (LAT) series of studies, which was aimed at further definition of the goals and objectives, activities, and systems necessary for conducting the lunar surface portion of the exploration strategy. Whereas the ESAS focused on the transportation system, the lunar architecture assessments concentrated on the activities conducted on the surface. During execution of the second half of the LAT studies, it was recognized that the lunar definition must be conducted in an environment that considers the most likely follow-on mission, namely the human exploration of Mars. Significant progress was being made in the definition of the lunar architecture and systems, but further refinement and confirmation of how these systems would either be used, or modified, for future exploration capabilities was required. In addition, the Science Mission and Aeronautics Research Mission Directorates were in the process of defining future Mars robotic missions as well as fundamental research activities related to future human exploration missions. Recognizing the need for an updated and unified reference architecture for human exploration of Mars, NASA Headquarters commissioned The Mars Architecture Working Group (MAWG) in January 2007 to develop the Mars Design Reference Architecture 5.0 (DRA 5.0). The MAWG was comprised of agency-wide representatives from the ESMD, Science Mission Directorate (SMD), Aeronautics Research Mission Directorate (ARMD), and Space Operations Mission Directorate (SOMD). In addition, an Agency Joint Steering Group of senior leadership was established at the beginning of the study to review the primary products that were produced by the MAWG, providing insight, guidance, and, ultimately, concurrence of recommendations made by the team. The strategy and implementation concepts that are described in this report should not be viewed as constituting a formal plan for the human exploration of Mars. Instead, this report provides a vision of one potential approach to human Mars exploration that is based on best estimates of what we know. This approach is used to provide a common framework for future planning of systems concepts, technology development, and operational testing. In addition, it provides a common reference for integration between multiple agency efforts including Mars robotic missions, research conducted on the International Space Station (ISS), as well as future lunar exploration missions and systems.