Science in NASA's Vision for Space Exploration (2005)

We live in an extraordinary period of exploration. Over the last few decades, humanity has used space as a vantage point from which to dramatically advance the exploration of our planet, the solar system, and the universe. In this transformative era, our understanding of every aspect of the cosmos has been reshaped as a result of a process driven by science—the desire to gain a fundamental and systematic understanding of the universe around us. Many aspects of exploration share this characteristic and constitute a form of science as well. This synergism establishes an overarching perspective from which to view science as an integral part of NASA’s vision for space exploration.

On January 14, 2004, NASA received specific instructions from President George W. Bush to undertake a space exploration program with a clear set of goals, including implementation of “a sustained and affordable human and robotic program to explore the solar system and beyond.”¹ We have an opportunity, then, to pursue critical scientific questions that remain just beyond our grasp and to extend the human presence across the solar system and thus become a true space-faring civilization. The opportunities for future discovery are vast, encompassing our home planet Earth, the Moon and Mars and other places in the solar system where humans may be able to visit, the broader solar system including the Sun, and the vast universe beyond. Indeed, there is an extraordinary richness to the opportunities, but of course also a sobering reality, given the need to consider the limitations of available resources.

The issue thus is not what to pursue ultimately, but rather what to pursue first. Accordingly, the Committee on the Scientific Context for Space Exploration recommends the following guiding principles:²

• 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 robotic³ 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.

The appropriate science in a vibrant space program is, therefore, nothing less than that science that will transform our understanding of the universe around us, and will in time transform us into a space-faring civilization that extends the human presence across the solar system.

NASA has embarked on a strategic planning activity that is built around 13 top-level agency objectives (see Chapter 2). The committee has reviewed the objectives, particularly those relating to science, and finds them to be comprehensive and appropriate. They have the potential to encompass all of the scientific topics that should be pursued under NASA’ s broad mission statement, which in turn is supported by the recent policy directives governing NASA. However, to be thorough and effective, strategic planning will require much forethought and the involvement of a diverse scientific community, because many of the scientific and technological challenges cut across several of the agency’s objectives.

The breadth of NASA’s top-level strategic objectives is an important strength. The topics do not distinguish between science and human exploration but rather reflect the recognition that each objective offers the opportunity both to advance and to benefit from understanding of the universe in which we live, and each is a worthy endeavor in a robust space exploration program. The committee believes that exploration, in the broad sense defined in this report, is the proper goal for NASA.

The committee recommends that, as planning roadmaps are developed to pursue NASA’s objectives and as priorities are set among them, decisions be based on the potential for making the greatest impact and that the strategic roadmaps do the following:

• Emphasize the critical scientific or technical breakthroughs that are possible, and in some cases necessary, and

• Highlight how a vibrant space program can be achieved by selecting from an array of approaches to realizing potential breakthroughs across the full spectrum of goals embodied in NASA’s mission statement.

For many years priorities for space science research have been developed and recommended through decadal surveys conducted under the auspices of the National Research Council (NRC). These studies use a consensus process to identify the most important, potentially revolutionary science that should be undertaken within the span of a decade, and numerous mission and program concepts that do not meet this standard are not pursued. In that sense NASA’s science program currently is and always has been planned with the intent to generate the paradigm-altering science that NASA should undertake.

The committee considered how NRC science strategies and other reports can contribute to NASA’s strategic planning process, and it makes the following recommendations:

• The most recent NRC decadal surveys for the fields of astronomy and astrophysics, solar system exploration, solar and space physics, and the interface between fundamental physics and cosmology do provide appropriate guidance regarding the science that is critical for the next decade of space exploration. The committee recommends that these reports—Astronomy and Astrophysics in the New Millennium (2000), New Frontiers in the Solar System: An Integrated Exploration Strategy (2002), The Sun to the Earth—and Beyond: A Decadal Research Strategy in Solar and Space Physics (2002), and Connecting Quarks with the Cosmos: Eleven Science Questions for the New Century (2003)—be used as the primary scientific starting points to guide the development of NASA’s strategic roadmaps that include these areas.

• Other highly relevant, discipline-specific NRC studies provide guidance for prioritizing critically important biomedical and microgravity research that must be conducted to enable human space exploration. The committee recommends that these reports—A Strategy for Research in Space Biology and Medicine in the New Century (1998), Safe Passage: Astronaut Care for Exploration Missions (2001), Factors Affecting the Utilization of the International Space Station for Research in the Biological and Physical Sciences (2002), Microgravity Research in Support of Technologies for the Human Exploration and Development of Space and Planetary Bodies (2000), and Assessment of

Directions in Microgravity and Physical Sciences Research at NASA (2003)—be used as a starting point for setting priorities for research conducted on the International Space Station so that it directly supports future human exploration missions.

• Science for enabling long-duration human spaceflight is inherently crosscutting, spans many of the agency’s 13 new top-level objectives, and requires input from many fields of science and technology. Thus, no single decadal survey or combination of surveys necessarily can provide the totality of advice needed for the new programs that are anticipated under NASA’s vision for exploration. Also, no single scientific or engineering discipline can provide the expertise and knowledge required for optimal solutions to the problems that will be encountered in human space exploration. Therefore, simply redoing the decadal surveys would not provide ideal guidance for defining the science that will enable human space exploration. Instead, the necessarily crosscutting advice should come from interdisciplinary groups of experts rather than from traditional committees that have a single scientific focus. Therefore the committee recommends that NASA identify scientific and technical areas critical to enabling the human exploration program and that it move quickly to give those areas careful attention in a process that emphasizes crosscutting reviews to reflect their interdisciplinary scope, generates rigorous priority setting like that achieved in the decadal science surveys, and utilizes input from a broad range of expertise in the scientific and technical community.

• NASA’s robotic science program has enjoyed remarkable success, and it provides lessons that are worth applying to the human spaceflight program. The committee recommends that successful aspects of the robotic science program—especially its emphasis on having a clear strategic plan that is executed so as to build on incremental successes to sustain momentum, use resources efficiently, enforce priorities, and enable future breakthroughs—should be applied in the human spaceflight program.

New opportunities for research will arise as a result of human space exploration, and other research efforts will facilitate its success, but these two categories of science need to be treated differently. Science that is enabled by human exploration is properly competed directly with “decadal-survey” science⁴ and then ranked and prioritized according to the same rigorous criteria. For science to enable human exploration, competitive choices will depend on the criticality of the problem the science addresses and the likelihood that it will resolve the problem. For the former kind of science, understanding is an end in itself. For the latter, understanding is a means to the goal of resolving an identified problem, and the degree of understanding needed depends on the problem at hand.

The presidential policy directive on exploration also provides the context for deciding on the future of the space shuttle and the mission of the International Space Station. NASA is directed to retire the shuttle as soon as the assembly of the ISS is complete, which is assumed to be by 2010, and to focus the use of the ISS on supporting the goals of long-duration, human space exploration. Doing this in the most cost-effective way possible is essential for achieving NASA’s goals for robotic and human exploration.