• Exploration is a key step in the search for fundamental and systematic understanding of the universe around us. Exploration done properly is a form of science.

  • Both robotic spacecraft and human spaceflight should be used to fulfill scientific roles in NASA’s mission to explore. When, where, and how they are used should depend on what best serves to advance intellectual understanding of the cosmos and our place in it and to lay the technical and cultural foundations for a space-faring civilization. Robotic exploration of space has produced and will continue to provide paradigm-altering discoveries; human spaceflight now presents a clear opportunity to change our sense of our place in the universe.

  • The targets for exploration should include the Earth where we live, the objects of the solar system where humans may be able to visit, the broader solar system including the Sun, and the vast universe beyond.

  • The targets should be those that have the greatest opportunity to advance our understanding of how the universe works, who we are, where we came from, and what is our ultimate destiny.

  • Preparation for long-duration human exploration missions should include research to resolve fundamental engineering and science challenges. More than simply development problems, those challenges are multifaceted and will require fundamental discoveries enabled by crosscutting research that spans traditional discipline boundaries.


An important aspect of the roadmapping process for fulfilling NASA’s new major objectives will involve international activities. Many of the roadmaps will be more effective if they are developed in collaboration with the parallel similar efforts being conducted by space programs throughout the world. There exists already a rich history of successful international collaborations—a foundation worth strengthening, expanding, and building upon. In the committee’s view, it is the whole of humankind that pushes out the boundaries of the known universe, and it is therefore essential to encourage international collaborators.


One of the important ideas at the 2003 NRC space policy workshop4 was the need for an exit strategy for the space shuttle and the International Space Station (ISS), including the need for a focused mission for the ISS. The workshop recognized that human exploration could provide the context for deciding on the future of the shuttle and the mission of the ISS.5 In the January 2004 presidential policy directive on exploration, NASA is told to retire the shuttle as soon as the assembly of the ISS is complete, which is assumed to be by 2010,6 and to focus the research conducted on the ISS on supporting the space exploration goals. Indeed, in the FY2005 presidential budget request for NASA, it was argued that the


National Research Council, Issues and Opportunities Regarding the U.S. Space Program: A Summary Report of a Workshop on National Space Policy, National Academies Press, Washington, D.C., 2004.


Several NRC reports have addressed the implications of focusing ISS research on support of space exploration. For example, see A Strategy for Research in Space Biology and Medicine into the Next Century (1998), Review of NASA’s Biomedical Research Program (2000), Factors Affecting the Utilization of the International Space Station for Research in the Biological and Physical Sciences (2002), and Assessment of Directions in Microgravity and Physical Sciences Research at NASA (2003), all NRC reports published by the National Academies Press, Washington, D.C.


The policy guidance is ambiguous with respect to what should happen if ISS assembly is not completed by 2010. There exists a range of options on the matter that must ultimately be decided before exploration beyond low Earth orbit can reasonably commence.

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