The Beyond Einstein (BE) program is a set of five space missions designed to address important questions about physics and astrophysics. In 2003, NASA prepared a research roadmap proposing these five missions in order to study dark energy, black holes, gravitational radiation, inflation of the early universe, and Einstein’s theory of gravitation. In FY2007, congressional language prompted NASA and DOE to request the NRC to assess these missions and recommend which to develop and launch first using a funding wedge that will start in 2009. This report provides, for each mission, an analysis of its scientific impact, an examination of technical risk and a cost assessment, and a review of related policy and programmatic issues. The report concludes with recommendations to guide the programs development.