President George W. Bush has challenged NASA and the nation to once again explore
space and extend a human presence across our solar system. This new initiative
places the president squarely in support of moving civilization into the solar
system and into the cosmos.
Left unstated in the presidents challenge to NASA and Congress is specifically how the roles of humans and robots will be balanced. As a human explorer, I am excited about this challenge. But, more specifically, as an Apollo astronaut and a geologist, I am offended by the uninformed treatment given to human exploration of the Moon and planets by a few, generally nameless space scientists cited in the popular press.
Media reports of these reactions should identify the space scientists that have had a tepid response to President Bushs push to send astronauts to Mars. I suspect that most of those interviewed are not field explorers, geologists or otherwise. Some even may have their NASA funding tied to robotic rather than human space flight. Other critics would object strenuously to being removed from exploration in their own disciplines of science in order to pursue human space exploration.
Furthermore, most of these hidden critics apparently remain aggressively unaware of the extraordinary foundation of scientific knowledge about the origin and history of the Moon, Earth, planets and solar system that resulted from Americans exploring the Moon in person. This immense body of data and understanding could not be obtained by robotic exploration at anywhere near a comparable cost and probably not at all. It provides the foundation for the interpretation of data from most post-Apollo and future robotic exploration of the Moon and planets. Taking human explorers back to the Moon and to Mars and beyond may indeed add billions of dollars to the cost, as some point out, but to say that it would add not much in the way of discovery shows an extraordinary ignorance of the unique scientific legacy of human exploration of the Moon and of more than 150,000 years of human experience on our planet.
The term space exploration implies the exploration of the Moon, planets and asteroids deep space in contrast to continuing human activities in Earth orbit. Such near-Earth endeavors have less to do with exploration and more to do with international commitments, as in the case of the International Space Station, or prestige and technological development, as in the case of space programs in China, India, Japan, Europe and Russia. On the other hand, important basic research opportunities exist to exploit human and robotic use of Earths orbit. This research potential has not been fully recognized even after 40 years and the spectacular results from the likes of the Hubble Space Telescope.
For deep space, exploration should always use the best combination of human and robotic techniques. Robots clearly have additive value to ventures on the Moon and planets. Any task that can be automated at a reasonable cost should be left to robots, particularly with respect to repetitive data collection, deployment of static sensors, routine mining and processing of resources, and initial investigation of unknown or particularly hazardous environments.
On the other hand, humans bring unique capabilities to exploration in addition to fixing robots that dont work right or break. The human brain consists of a semi-quantitative supercomputer that is both programmable and reprogrammable by training, experience and preceding observations. Human eyes form a high-resolution, stereo-optical system of great dynamic range, and their integration with the brain provides capabilities for synergistic discovery and interpretation far beyond those of robotic cameras. Human hands constitute a still underutilized, highly dexterous and sensitive bio-mechanical system that, when integrated with the brain and eyes, are unmatched in future potential.
Most importantly, humans react spontaneously to the exploration environment, bringing instant creativity to bear on any new circumstance, opportunity or problem. Discovery of the critically important orange pyroclastic glass during the Apollo 17 mission illustrates this fact in spades. And, if any of the human field geologistsreading this page had been exploring Mars in place of the recent pair of rovers, they would have quickly resolved any doubt about the nature of the outcrops. They would have explored far more terrain, integrating their findings into the big picture of martian history. Human explorers would have been able to test the hypotheses that Opportunity was exploring sulfur-rich evaporites or the oxidized remains of the martian equivalent of an epithermal sulfide deposit, confirming or rejecting either idea in favor of a better one based on close observation and judicious use of a geological hammer. As important as cost-effective scientific exploration of new worlds is for understanding nature and our place in it, three other facets of future human activity in space override even these arguments. First is the natural urge, common to all species, to expand accessible habitats and thus enhance a species prospects for long-term survival. In this regard, settlement of the Moon and Mars clearly is now technically feasible for our species. Moreover, with settlement, the technology would exist to protect Earth from asteroid or comet impact.
Second, settlement of the Moon offers specific benefits to those left behind on Earth in the form of its helium-3 resources. This lunar fuel for fusion power generation, not available in commercially viable amounts on Earth, potentially can support an environmentally benign and economically competitive alternative to the long-term use of fossil and nuclear fuels.
Finally, if sustained by Congress and future presidents, a special benefit from deep space exploration and settlement exists if Americans lead that activity. The transplantation of the institutions of freedom to those human settlements eventually will sprout and grow on the Moon and Mars and possibly beyond. This is our special gift and our special obligation to the future.