Historians often refer to key periods in time as "inflection points" -- times when the course of human events began to veer away from one particular direction toward another. The history of space exploration is replete with such turning points: the launch of Sputnik, the first Apollo Moon landing, and the explosion of the Space Shuttle Challenger are among the most well known. Today, NASA's highly-successful robotic solar system exploration program, and the Mars exploration program in particular, is on the brink of its own major inflection point. The time has come, from both a scientific and exploration standpoint, for NASA to embark on a robotic mission to bring rock and soil samples back from Mars, but the Agency -- and the administration -- appear to be shying away from the challenge. Will the balance tip toward progress and discovery, or delay and stagnation?
The past 15 years have seen an amazing renaissance in our exploration of the Red Planet. A well-coordinated program of four robotic orbiters (three from NASA, one from the European Space Agency (ESA)), two stationary landers, and three mobile rovers have delivered an incredible and steady supply of images, maps and chemical/mineral data about Mars. These missions have enabled astronomers, planetary scientists and astrobiologists to discover that Mars -- though today cold and dry and barren on its surface -- was once much more like the Earth, with active volcanoes and tectonics and flowing surface and subsurface liquid water. The place was, by all reasonable measures, a habitable world. A new rover, dubbed "Curiosity," launched recently and is set for an August 5 landing and a two-Earth-year mission to further investigate the habitability of our planetary neighbor, focusing especially on the possible presence of organic molecules preserved in an ancient, once-watery environment. Another NASA orbiter, called "MAVEN," is set for launch next year to study even more details about the planet's atmosphere and climate.
Presidents and politicians talk about "special relationships" between nations. For example, the U.S. has a special relationship with England because of our close-knit shared heritage and culture. Similarly, many planetary scientists feel that the Earth and Mars have a special relationship, because of our close-knit origins and early histories and because Mars is -- today -- still the most Earth-like place in our solar system besides the Earth itself. We see photos of its stark ruddy landscapes and feel a sense of familiarity with the place, despite knowing the reality of it being an incredibly hostile and alien environment for humans. If we imagine turning back the clock, though, 3 or 4 billion years, we can reasonably wonder if life began or thrived in that earlier warmer, wetter environment, as it did on the early Earth. Nowhere else in our solar system can we find a closer, more inviting place than Mars try to answer the question, "Is (or was) there other life out there?" As we continue to make incredible discoveries about the immensity of the cosmos and our tiny place within it, almost no other question resonates so strongly in the human soul than "Are we alone?"
And this is precisely why we are at a critical inflection point. Despite the incredible scientific discoveries and enormous public excitement and good will towards NASA that have come from the recent Mars Exploration Program, despite the fact that we are now able to search for and potentially detect the presence of biologic organic molecules (or their remains) in the Martian environment today, and despite the fact that NASA has assembled an incredibly competent and motivated nationwide cadre of thousands of skilled engineers, managers and scientists who know how to land and operate complex robots on and above Mars unlike anyone else in the world -- despite all that -- funding for future Mars missions, including the next step of sample return, is being dramatically cut. Some of our political leaders appear ready to take this exciting and inspirational part of our space exploration program off the rails altogether.
This is "penny wise and pound foolish" thinking. The proposed cuts to the Mars program, including NASA's withdrawal from planned missions with ESA for a new orbiter in 2016 and a new rover in 2018 to build on recent discoveries, amount to less than about 2 percent of NASA's annual budget, which is itself less than 0.5 percent of the entire U.S. budget. But that small percentage would end up severely damaging one of the most successful and most publicly supported and admired programs that NASA has.
It has been argued that the Mars program can take these cuts because it has been so successful, and because the latest rover mission, Curiosity, and the soon-to-be-launched MAVEN orbiter, have passed or will soon pass their peak spending rates, providing a logical opportunity to scale back funding. Hogwash. Cutting off such a successful, carefully formulated program of missions now would be like cancelling the Apollo landings after finishing only the Mercury and Gemini programs -- close enough, right? U.S. taxpayers have made a significant investment in NASA over the past few decades to build this program of systematic, paradigm-shifting solar system exploration missions. Now is the time to reap the scientific, educational and inspirational profits from that investment, not to turn back and squander the opportunity to answer fundamental questions about our place in the universe.
The planetary science community and the National Academy of Sciences recently conducted an extensive survey to identify the highest-priority new robotic missions for the next 10 years. Topping that list of plans for NASA's most ambitious new "flagship" class of missions is the desire to bring back a set of carefully selected Martian rock and soil samples for detailed study in laboratories here on Earth. The ability to use the latest technologies in multiple laboratories on Earth and to selectively bring back sedimentary rock samples that have the best chance to preserve potential past Martian biosignatures, combined with the demonstrated scientific advances made by previous human and robotic sample return missions from the Moon, asteroids, and comets, helped the community arrive at a clear consensus: in order to make the next big advances in our search for life on Mars (as well as our understanding of the origin of life on Earth), Mars sample return must be the next step. Many in the astronaut community also think that bringing samples back with a robotic mission is an essential precursor to an eventual human exploration mission to Mars.
As currently envisioned, such a Mars sample return campaign would have begun with the 2018 joint NASA-ESA rover to cache some well-selected samples, to be followed by two other missions to launch that cache into Mars orbit (in 2025) and return them to Earth (in 2026). Stable -- flat -- funding for NASA's missions would have allowed this plan to begin. But the proposed 20 percent cut to the planetary science portfolio would make it impossible to carry out.
The proposed cuts to NASA's planetary science budget go deeper than just the Mars program and its flagship mission, however. The cuts would nix hopes for missions to other exciting astrobiology hotspots in the outer solar system, too, like Jupiter's moon Europa (which likely harbors the largest water ocean in the solar system), or Saturn's large moon Titan (which has a thick atmosphere of organic molecules and liquid "seas" of methane, ethane and propane). Lunar exploration plans would be scaled back, and smaller-class missions would be delayed. Even basic research and education funding would be scaled back. We're facing the prospects of declining U.S. leadership in the exploration of our solar system, including no flagship-class missions for at least a decade. Imagine what gaps we would have in our textbooks without the likes of Viking, Voyager, Galileo, and Cassini. Flagship missions provide amazing science returns on investment.
The last such inflection point for NASA was in the late 1970s/early 1980s, when NASA's science program was sharply curtailed to help fund the Space Shuttle and the nascent Space Station. Grassroots efforts, like those of The Planetary Society (co-founded by Carl Sagan) helped to save NASA's planetary exploration program back then and thus to enable the incredible discoveries in solar system exploration that we have all been fortunate to experience recently. Similar efforts are needed today to help save NASA's science programs from the budget axe, which is why I'm spending time this week, during a critical time in the U.S. budget cycle, to join The Planetary Society and other organizations like the American Astronomical Society's Division for Planetary Sciences, the American Geophysical Union, the Geological Society of America, the Meteoritical Society, the SETI Institute, and others to appeal to our elected representatives on the relevant House and Senate Appropriations Subcommittees in Congress to restore the proposed cuts to NASA's planetary exploration program. If you care about this issue, now is the time to join in this fight as well. Nothing less than the future is at stake.
Jim Bell is an astronomer and planetary scientist, a professor in the School of Earth and Space Exploration at Arizona State University in Tempe, and the president of The Planetary Society, the world's largest public space advocacy organization. He is the lead scientist for the Pancam color stereo cameras on the NASA Mars rovers Spirit and Opportunity, is a member of the science camera team on NASA's Curiosity rover, and has authored several space photography books, including Postcards from Mars, Mars 3-D and Moon 3-D.