Furthermore, these participants were inclined to agree that such a goal should be the human exploration of the solar system beyond low-Earth orbit. They viewed exploration as the acquisition of new knowledge: knowledge of space as a place for human activity, knowledge of our solar system, and knowledge of the universe beyond our solar system. They also saw exploration as a basic human desire, innate in our genetic code, and noted that human spaceflight can be the modern realization of that basic trait.


The important question, of course, is how does the nation proceed in order to achieve a space exploration goal? How do we ensure success? Our workshop recognized that exploration of our solar system is a long-term endeavor, which needs to be accomplished with a series of incremental steps. In this sense, the human exploration efforts can learn from the successes of NASA’s science programs. Workshop participants observed that certain key factors have contributed to the success of the science program: there are clear goals in the science program established by the science community’s interest in pursuing the most challenging scientific questions; there is strategic planning; and there has been a steady sequence of accomplishments. The science program is executed via a series of individual steps that can accumulate success, from which progress can be measured and momentum sustained.

So what are these steps for human exploration? Our workshop participants envisioned a number of key efforts—the development of building block technology, the dedication of ISS research to solving questions posed by long-term spaceflight, eventual phasing out of the space shuttle, and the use of robotic precursor missions to both the Moon and Mars. These steps also are part of NASA’s new roadmap for space exploration.

In 1997 the Space Studies Board published a report which I think offers several complementary ideas for a roadmap for space exploration. Titled The Human Exploration of Space, the report reviews three important areas of consideration that the Board felt were necessary to address at the initial stages of a program in human exploration. First is the enabling science for human exploration. This defines the conditions necessary to maintain the health and safety of astronauts and to ensure their optimal performance. Research areas that are enabling science can be classified according to their degree of urgency. Critical research issues, or “showstoppers,” are those for which inadequate scientific data lead to unacceptably high risks to any program of extended space exploration. The second area of consideration is the science that is enabled by a human exploration program, specifically human missions to the Moon and Mars. The third area of consideration is one of management and organization—what should be the relationship between the scientific community and NASA, between scientists and engineers within NASA, as a program of human exploration moves forward?

The 1997 SSB report identifies the following as those showstopper, critical research issues: the long- and short-term effects of ionizing radiation on human tissue; the radiation environment inside proposed space vehicles; the benefits and costs of different radiation shielding techniques; the detrimental effects of reduced gravity and transitions in gravitational forces on all of the body’s systems and on bones, muscles, and mineral metabolism; and the psychological effects of long-duration confinement in microgravity with no escape possible. These and several other issues related to the human biological response to space exploration are detailed and prioritized in two more recent National Academies reports: A Strategy for Research in Space Biology and Medicine in the New Century, published by the Space Studies Board; and Safe Passage: Astronaut Care for Exploration Missions, published by the Institute of Medicine.

As for the connection between scientists and engineers, I was struck at our workshop by how members of the scientific community appeared willing to embrace the idea that the human spaceflight program can be a contributor to real scientific progress. I think our participants would echo the conclusions of the 1997 report which called for an integrated science program to accompany human missions to the Moon and Mars, as well as the close coordination between human spaceflight and science program staff in the implementation of an exploration program. Participants at our workshop said many times that the reason the process of setting research priorities by the scientific community has had a positive impact on NASA’s science programs is that it creates within the scientific community, a community that in the language of Congress can be considered the constituency of the science programs, a sense of ownership in the program. That feeling of ownership creates what we called a constructive tension between NASA and the science community, which ultimately empowers the program to excel. We observed this sense of ownership to be missing from the human spaceflight part of NASA, but that does not have to remain the case.

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