Destination Mars (27 page)

A
s compelling as the robotic exploration of Mars is, sometimes it takes “boots on the ground” to decipher the secrets of a new world. With human flights to Mars still in the future, some intrepid researchers have taken matters into their own hands. They have organized expeditions to Mars…on Earth.

As our understanding of the Red Planet has expanded, it has become clear that there are places on Earth that mimic Mars in some important ways. If this discussion were taking place in 1904, we might discuss the Mojave Desert in California or the canals of Holland. But in the twenty-first century, we understand far more about Mars and there are some surprising parallels on our own planet. Devon Island in the Arctic…the Atacama Desert in Chile…the dry valleys of Antarctica. There are more, but these are some of the primary research targets of scientists seeking a so-called Mars analog on Earth, usually to study primitive forms of life, soil conditions, or research techniques.

One of the most compelling of these endeavors is the Flashline Research Station, or FMARS, set up on Devon Island, about one thousand miles south of the geographic north pole. Run by an organization called the Mars Society, it is a cooperative venture between the society, NASA, and academia. The effort to build the station was spearheaded by Dr. Pascal Lee, an accomplished research scientist with NASA at the Ames Research Center, and Dr. Robert Zubrin, a brilliant aerospace engineer formerly at
Lockheed Martin and a founder of the Mars Society, a space-exploration advocacy group. Zubrin has long been an advocate of finding cheaper and more effective ways of traveling to Mars, for both robots and human beings. The Flashline Station has proved to be an excellent exercise in what such a mission, once landed upon the Red Planet, might entail.

Zubrin was a cofounder of the Mars Society, which has funded, has built, and operates the station. It was not a simple task. Many years of intense fundraising, multiple design studies, fabrication, and the transport of the prefab materials to Northern Canada were just the beginning. Much of the prefab elements were severely damaged before final construction, and a lot of repair work had to be done on-site on the remote, frozen landscape of Devon Island. Then a crane failed, and the final assembly needed to be carried out via old-fashioned block and tackle. The construction crew had departed, and it was up to Mars Society volunteers (including Zubrin himself) and a film crew from the Discovery Channel (who set down their cameras and joined the volunteers) to complete the structure. It was chilly, exhausting work. But by 2000, the habitat was complete and ready for the first crew.

Since 2000, crews picked from academia and industry have spent rotations at Flashline Station. This is a true simulation; the six or seven crew members must don simulated pressure suits when they work outside during EVAs (Extra Vehicular Activities), including a timed depressurize-pressurize cycle upon leaving or entering the station, or habitat, as they refer to it. Communications with the outside world are typically delayed by twenty minutes to simulate the one-way travel time of radio from Mars to Earth. The station itself is a large cylindrical unit, perched upon supports that hold it just off the icy surface. Inside are basic accommodations for a small crew, including bunks, a galley, research stations, a satellite computer link, and other common areas. The only real concession to Earth-bound logistics is the
single crew member armed with a shotgun, as well as nonlethal deterrents, to guard against polar bears that might take an interest in a space-suited snack.

Once outside in the cold Arctic air, crew members either perform experiments and maintenance duties near the station or climb aboard small gas-powered ATVs to traverse to specific targets, usually for meteorological, biological, or geological activities. Daily logs are kept by each member.

The entire effort is designed to mimic as closely as possible (on a limited budget) a stay on Mars of up to a month or more. Participants have ranged from NASA scientists to university grad students to journalists.

Data from these stays have provided valuable information on psychological and logistical problems, research and experimentation techniques, and more. Of particular interest have been their studies of the region itself. The station overlooks the Haughton Impact crater, a fourteen-mile-wide site where a large extraterrestrial object slammed into the Earth some thirty-nine million years ago.

Crew members continue to serve rotations at the Flashline Station, and will continue to do so for the foreseeable future. Interested? Laypeople are now being encouraged to apply…

There are other ways to research Mars on Earth, however. Dr. Chris McKay is behind such an effort. After earning a doctorate in astro-geophysics from the University of Colorado in 1982, he went on to become a research scientist at NASA's Ames Research Center in California. McKay has spent time at most of the Mars analog sites, but one of the more remarkable trips, especially in terms of results, has been a journey to the Atacama Desert, one of the driest, most desolate places on Earth. McKay was prompted to explore the region by the discovery of perchlorates by Mars Phoenix in 2008. The results of the probe's experiments reopened the lingering question of the confusing life-science results from Viking, some thirty-two years earlier. And since a trip to Mars was
out of the question for the time being, the Atacama was the next best thing.

The desert lies at an altitude of three thousand feet and is blocked from rainfall by two bordering mountain ranges. The soil is virtually sterile and is fifty times more arid than the Mojave Desert. Misty rain drizzles onto the region an average of once every ten years. Items implanted in the soil—whether plants or microbial—die quickly. Other than atmosphere and temperature
conditions, it is a near twin of Mars, and has apparently been since its formation over fifteen million years ago. It is officially the “deadest place on Earth” in its dry core region.

McKay had been to the Atacama a number of times. He took some soil from the region and repeated, as closely as possible, the Viking life-science experiments—and the controversy over Viking's results was reignited almost overnight.

Earlier research efforts had shown that the few organic substances present in the soil were so dispersed and were released at such high temperatures that, had Viking landed in the Atacama instead of Mars, the results of the experiments would have been the same: no life would have appeared, despite the fact that it existed.

In 2003, McKay discussed the results of another repeat of the Viking life-science experiments. He tested the microbial nutrient broth in the coastal region of the Atacama, where there is a bit more microbial life, and the nutrients were consumed. A variant of the broth from the Viking experiment was prepared that was not designed to support life, but was still consumable, and it was not metabolized by the microbes. But in the drier, deader inner core, both the microbe-friendly and non-microbe-friendly broths were used up equally. It appeared that the majority of the Viking scientists had been right—something else, possibly a strong oxidant like perchlorate, was reacting with the liquids.

But in a similar experiment performed after Phoenix confirmed perchlorate in Martian soil, which was still in doubt during the Viking era, organics were observed using similar instrumentation and interpreted with the foreknowledge of perchlorate in the soil. “Contrary to thirty years of perceived wisdom, Viking did detect organic materials on Mars,” McKay said upon reviewing the results.
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“It was only by having it pushed on us by Phoenix where we had no alternative but to conclude that there was perchlorate in the soil…. Once you realize it's there, then everything makes sense.”

This conclusion is based, as mentioned, on the evidence of perchlorate in the soil. With perchlorate present, small amounts of organics could have been present on the Viking samples, but would have been destroyed in the heating process.

To strengthen the case, and this was the clincher, McKay and co-researcher Dr. Rafael Navarro-González reexamined the chemical results of the Viking experiments. Elements released from the pyrolitic experiment (the gas-chromatograph examination of gasses released by the baking of a soil sample) had shown traces of chemicals that were dismissed by the researchers of the time as Earth-based contaminants, that is, things carried up from Earth aboard the lander, despite the extensive efforts at sterilization. But when McKay and Navarro-González compared the Viking charts to those generated by their Atacama soil experiment, the results were almost identical. It appeared that there had been traces of organic carbon in the Viking sample after all.

Note that the discovery of organics does not mean life, but the organic building blocks of life. Still, this was a major finding, and for the “evidence of life” camp in the three-decade Viking life-science result discussion, welcome news. More answers should be provided by the MSL mission when it arrives at Mars in 2012.

McKay and many others have also studied the dry lake valleys in Antarctica. These odd regions, located on the coldest continent in the world, are also the very driest. Rainfall is almost unknown (true rain is estimated to have last fallen in the region about fifteen million years ago), and what moisture is deposited is rapidly depleted by the fierce katabatic (gravity-fed) winds that hurl themselves off the nearby slopes at up to 200 mph.
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Add to this an average temperature of 4°F, and you have a rather similar environment to Mars in many important ways.

There are also lakes in this exotic region, covered with a thin sheet of ice year-round. They are highly alkaline and ten times as salty as the open sea. These traits make them somewhat akin to the water found on Mars in the distant past. But it is the dry areas
that fascinate the Mars crowd. Life is highly challenged in the dry valleys; there is no vegetation and no major life-forms anywhere to be found. Life, where it can be discerned, hangs on tenaciously by a thin thread. But life finds a way, and life there is: In the lakes, mats of algae can be found. Bacteria, yeast, and varied fungi can be found in the nearby soil. The most advanced life takes the form of nematodes, tiny worms.

What fascinates people like McKay is the phenomenon of
eternal permafrost.
Large regions of the Canadian Arctic and other similar regions are made up of permafrost, but it melts in the summer season, changing chemistry and soil dynamics. The dry valleys, however, consist primarily of rock and soil over ice which never thaws—much like a lot of Mars. This has proved to be an ideal environment for a number of research projects.

Some of these projects are mechanical in nature. As the soil is so Mars-like, prototypes for drills and scoops, destined to fly on Mars probes, are tested here regularly. The sampling system for the Mars Phoenix was tested here. Peter Smith, the head of that program at the University of Arizona, was struck by the similarity between this region and the Red Planet. “Those upper valleys are the best analog for the Phoenix site,” he has stated. “The soil temperatures are always well below freezing, ice is stable about fifteen inches below the surface, and the extreme conditions challenge life-forms to the maximum. This is as close as we can get to Martian conditions.”
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The wet chemistry lab for Phoenix was also put through its paces here, a valuable simulation for the harsh conditions found near the Martian poles.

The drill for the MSL rover was tested in the dry valleys; it's a percussion drill that pounds the soil as it drills into it in order the get the greatest bang for the (weight) buck possible. This kind of testing is more challenging than it sounds. Deep in the hills, far from the nearest bit of civilization, teams must operate the drills while generating their own power and carrying spare parts. Everything must be helicoptered in—and out—including human waste.
And the particulars of the drill must be carefully measured: allow the bit to get too hot, and it will melt the very ice it is attempting to sample. Allow the ice being drilled to refreeze, and that's the end of the drill bit, and the sample.