Until now, space exploration has involved either robotic or human expeditions.
We launch probes to distant worlds to collect scientific data. Closer to home,
humans regularly travel to Earth orbit after having once ventured to the Moon.
Robotic missions are relatively inexpensive, costing, on average, several hundred million dollars apiece. By contrast, human exploration is extremely expensive. To place the first humans on the Moon consumed, at one point, about 5 percent of the annual federal budget and took nearly a decade to complete. The price tag for a human expedition to Mars a goal that generates broad public interest is many tens of billions of dollars; and reaching that goal could consume at least another decade.
Mars beckons for exploration, robotic or human. The United States has committed a focused program, with launches scheduled every Mars opportunity. Europe, Japan and Russia also have developed missions. Mars is special because of the prospect of life life past may have been there, life future will certainly be sent there. The human goal of understanding ourselves drives us there.
But the robotic program appears to be a dead-end; as missions get more complex and expensive, they get cancelled. Three times in the last 20 years, development of the Mars Sample Return mission was begun, and three times it was cancelled as soon as the cost was estimated.
Human space exploration is in worse shape. No one knows where it is leading. The space station is variously argued as the next logical step, without saying to where; or others see it as a super-expensive science laboratory without much science interest. The Columbia accident has once again prompted calls for defining a purpose for human space flight one that justifies its risk and public expense. We submit that the only task that can provide such justification is the exploration of new worlds and discovery of new knowledge about ourselves.
Rather than argue about whether human or robotic exploration is preferable, a third way bridges the gap, providing pathways for both human and robotic programs. The Planetary Society has dubbed this approach Mars Outposts.
Mars Outposts would consist of specially designated research sites on the Red Planet, equipped with permanent communications, navigational systems, and other technologies to support intensive robotic missions and, most important, vicarious public participation. The areas would become, in a sense, martian Antarcticas, places of high scientific interest where researchers from around the world could collaborate to learn about the planet.
At the sites, rovers, balloons and other probes would comprehensively investigate the surrounding terrain. Thanks to continuous signals broadcast to Earth and distributed through the Internet, humans worldwide would be able to participate in the exploration of the planet. For instance, via camera lenses on a rover, students could explore the landscape and command the vehicle, maneuvering through dry river basins and through the polar regions. Mars is a magnificent place. A deep swath cutting across the face of Mars dwarfs Americas Grand Canyon. Olympus Mons rises more than twice the height of Mount Everest.
With Mars Outposts, the whole world could collectively experience the thrill of exploring another world. We could all become the Lewises and Clarks of Mars.
Beyond the intrinsic value of each robotic step, the Mars Outposts approach incrementally establishes the infrastructure needed for human expeditions and thus greatly reduces costs and increases safety. The outposts could become future landing sites. The same communications and navigational systems used for the robotic probes could later support a human mission. The robotic infrastructure, for instance, could facilitate the production and storage of propellant and also breathable oxygen produced on Mars from the planets thin, carbon dioxide atmosphere thereby reducing the payloads launched from Earth to support initial robotic sample return and subsequent human exploration and return to Earth.
Additionally, the outposts would allow scientists and engineers to determine the tasks best accomplished by robotic technologies and those more appropriately performed by humans. The new paradigm of human-machine symbiosis could be built step by step.
Humans will travel to Mars; we just dont know when. The next step toward realizing this dream could be aboard the International Space Station conducting research there on keeping humans healthy in space over extended periods and preparing them for the long and arduous expedition to Mars. The station also could be used to develop habitat technology for a martian crew.
As the space station is an international endeavor, so, too, will be a human expedition to Mars. And so, too, would be the Mars Outposts. Together, all would share the costs, risks, and opportunities of robotically learning about Mars and progressing to the human phase. The outposts would catalyze the transition to direct probing of the habitability of Mars.
It is a propitious time for the U.S. president to initiate the Mars Outposts program. Five probes are heading to Mars this year from the United States, Europe and Japan, to join the two already there. The United States is in the throes of making a decision about what to do about human space flight after Columbia, and what to do with the space station. A sense of purpose, a goal, is needed. We are alive at a time when we are able not only to dream about distant worlds but to explore them together. Those dreams are wishes, which we badly need in the face of so much present-day strife and conflict. Ours is the first generation of the Space Age. It can be our fortune to reach into the heavens as one and open our eyes upon a new world.