Book excerpt: The Committee for the Review of NASA's Pioneering Revolutionary Technology (PRT) Program and its three supporting panels were charged by the National Aeronautics and Space Administration (NASA) with assessing the overall scientific and technical quality of the PRT program and its component programs, along with their associated elements and individual research tasks. Major issues addressed in the review include (1) research portfolios, (2) research plans, (3) technical community connections, (4) methodologies, and (5) overall capabilities. As reflected in the organization of the report, a two-pronged assessment was developed. Each panel provided a detailed assessment of the program under its purview, which was refined and updated over the course of the review. The committee, composed mainly of representatives from each panel, integrated and evaluated the panel results and provided top-level advice on issues cutting across the entire PRT program.