the robots in that play were defined by their autonomous behavior. Armstrong then observed that although spacecraft do not live up to that original definition of the term, their onboard programming and ability to be remotely controlled from Earth have made for valuable accomplishments.

Armstrong said that the Apollo program benefited from early probes sent by the United States to map the Moon and test the lunar surface. He also noted that these probes have accumulated 13 successes and 16 failures, not unlike the (almost) 1 in 3 Mars probe success rate. Increasing the success rate of future probes through increased autonomous capability, he thought, would depend on extended systems reliability and performance range. As their separation from Earth increases, spacecraft need more autonomy. Summarizing his view on the rationale for space exploration, Armstrong said it is to increase our knowledge of space and to develop the means to use it to our advantage.

Answering a question from moderator Charles Walker about the relative roles of government and industry, Armstrong observed that while industry is willing to engage in enterprises incurring very short-term financial losses, it does so only if it sees those losses leading to longer-term profitability,which limits the role it can perform. Perhaps not-for-profit corporations can exercise somewhat more business flexibility, he suggested, but the principle is similar.

Another question about Armstrong’s view on appropriate roles of humans and robotics in space exploration and development elicited the reply that NASA should have kept human spaceflight and robotics investments together, working toward common mission goals. Mission accomplishment is the overriding goal in Armstrong's view; achieve that, and safety will usually follow.

The final question, from Darrell Branscome, asked how public support can be increased. Armstrong's response was that publicly funded endeavors are proposed by the presidential administration and then approved and funded by the Congress, which is supposed to reflect the public will. But the public will is elusive. Because most people do not have the information at hand to make informed decisions, they rely on the Congress to make the best decision possible.

David Goldston began his remarks by noting that they were his own, not those of particular members of Congress or a congressional committee. He said the rationale for human spaceflight was less clear than the rationale for science-driven robotic missions. The latter missions are well defined by virtue of the peer review process. In Washington, D.C., he said, the rationale for human missions is fuzzy, and most explanations cannot survive rigorous scrutiny. He summarized the basic reasons for space exploration as follows:

  • Science. While science is often cited as a rationale for human missions, much science can be conducted robotically, and there are no clear criteria for determining when sending humans on science missions is worth the additional expense and risk. In proposing its space exploration vision for NASA, the White House has carefully stated that it is not science-driven but informed by science. Goldston thought that was an honest position, but NASA is not using the same language in its discussions of the new vision and should be doing so.

  • Education and public excitement. In Goldstein’s opinion, this is the most commonly stated rationale but the weakest one. He noted that U.S. education was

The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement