Historically, the United States has been a world leader in aerospace endeavors in both the government and commercial sectors. A key factor in aerospace leadership is continuous development of advanced technology, which is critical to U.S. ambitions in space, including a human mission to Mars. To continue to achieve progress, NASA is currently executing a series of aeronautics and space technology programs using a roadmapping process to identify technology needs and improve the management of its technology development portfolio. NASA created a set of 14 draft technology roadmaps in 2010 to guide the development of space technologies. In 2015, NASA issued a revised set of roadmaps. A significant new aspect of the update has been the effort to assess the relevance of the technologies by listing the enabling and enhancing technologies for specific design reference missions (DRMs) from the Human Exploration and Operations Mission Directorate and the Science Mission Directorate. NASA Space Technology Roadmaps and Priorities Revisited prioritizes new technologies in the 2015 roadmaps and recommends a methodology for conducting independent reviews of future updates to NASA's space technology roadmaps, which are expected to occur every 4 years.

NASA's Office of the Chief Technologist (OCT) has begun to rebuild the advanced space technology program in the agency with plans laid out in 14 draft technology roadmaps. It has been years since NASA has had a vigorous, broad-based program in advanced space technology development and its technology base has been largely depleted. However, success in executing future NASA space missions will depend on advanced technology developments that should already be underway. Reaching out to involve the external technical community, the National Research Council (NRC) considered the 14 draft technology roadmaps prepared by OCT and ranked the top technical challenges and highest priority technologies that NASA should emphasize in the next 5 years. This report provides specific guidance and recommendations on how the effectiveness of the technology development program managed by OCT can be enhanced in the face of scarce resources.

For the National Aeronautics and Space Administration (NASA) to achieve many of its space science and exploration goals over the next several decades, dramatic advances in space technology will be necessary. NASA has developed a set of 14 draft roadmaps to guide the development of such technologies under the leadership of the NASA Office of the Chief Technologist (OCT). Each roadmap focuses on a particular technology area. OCT requested that the National Research Council conduct a study to review the draft roadmaps, gather and assess relevant community input, and make recommendations and suggest priorities to inform NASA's decisions as it finalizes its roadmaps. The success of OCT's technology development program is essential, because technological breakthroughs have long been the foundation of NASA's successes, from its earliest days, to the Apollo program, to a vast array of space science missions and the International Space Station. An Interim Report of NASA's Technology Roadmap identifies some gaps in the technologies included in the individual roadmaps. The report suggests that the effectiveness of the NASA space technology program can be enhanced by employing proven management practices and principles including increasing program stability, addressing facility issues, and supporting adequate flight tests of new technologies. This interim report provides several additional observations that will be expanded on in the final report to be released in 2012.

Space Nuclear Propulsion for Human Mars Exploration identifies primary technical and programmatic challenges, merits, and risks for developing and demonstrating space nuclear propulsion technologies of interest to future exploration missions. This report presents key milestones and a top-level development and demonstration roadmap for performance nuclear thermal propulsion and nuclear electric propulsion systems and identifies missions that could be enabled by successful development of each technology.

Both the President's commission on how to implement the President's space exploration initiative and Congress asked the NRC undertake an assessment and review of the science proposed to be carried out under the initiative. An initial response to that request was the NRC February 2005 report, Science in NASA's Vision for Space Exploration. While that report's preparation, NASA created capabilities and strategy roadmapping efforts which became the object of the next phase of the NRC review. The new NASA administrator modified that NASA activity resulting in changes in the NRC review effort. This report provides a review of six science strategy roadmaps: robotic and human exploration of Mars; solar system exploration; universe exploration; search for earth-like planets; earth science and applications from space; and sun-earth system connection. In addition, an assessment of cross-cutting and integration issues is presented.

In January 2004, President Bush announced a new space policy directed at human and robotic exploration of space. The National Academies released a report at the same time that independently addressed many of the issues contained in the new policy. In June, the President's Commission on Implementation of United States Space Exploration Policy issued a report recommending that NASA ask the National Research Council (NRC) to reevaluate space science priorities to take advantage of the exploration vision. Congress also directed the NRC to conduct a thorough review of the science NASA is proposing to undertake within the initiative. This report provides an initial response to those requests. It presents guiding principles for selecting science missions that enhance and support the exploration program. The report also presents findings and recommendations to help guide NASA's space exploration strategic planning activity. Separate NRC reviews will be carried out of strategic roadmaps that NASA is developing to implement the policy.