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Mars

The next new frontier

Created date

September 25th, 2012

It all started with a four-pound rock wedged in the snowy landscape of Allan Hills, Antarctica. About the size of a man s fist, it appeared to be your ordinary, run-of-the-mill meteorite, that is, until 1996, when closer study revealed that it was actually from Mars and full of what appeared to be remnants of microscopic life forms. Catalogued in NASA s collection as ALH 84001, the meteorite contained gasses native to Mars, as well as the fossils of primitive, bacteria-like structures smaller than any cellular life known on Earth. From this tiny acorn grew a mighty oak a series of missions to the Red Planet, all in an effort to determine whether or not we are alone in the universe.

Roving the surface

Over the last 15 years, NASA has conducted close to half a dozen unmanned rover expeditions on the Martian surface, collecting data related to the planet s climate, geology, atmosphere, and signs of water-related processes such as precipitation and evaporation any evidence that might hint at an environment once capable of supporting life. NASA successfully deployed its Sojourner rover on Mars in 1997, proving that it could deliver a land vehicle equipped with a payload of scientific instruments safely, efficiently, and at a fraction of the cost associated with past missions particularly the Viking probes of the 1970s, which were 23 times more expensive. The space agency followed suit in 2003, sending the rover Spirit to the Mars crater Gusev and the rover Opportunity to the Meridiani Planum, a plain located just south of the planet s equator. Spirit and Opportunity were designed to look at two different regions on Mars and determine whether there was liquid water on the surface in the past, and we think we ve found it, says Randii Wessen, a mission systems engineer at NASA s Jet Propulsion Laboratory in Pasadena, Calif. During these missions, we ve pulled together some pretty strong evidence to suggest that Mars was wet at one time, which means that it used to have more of an atmosphere than it does now. The next step, according to Wessen, is the more daunting task of assigning a timeline to the transition from a wet and possibly life-sustaining environment to one with only seven one-thousandths of an atmosphere made up almost entirely of carbon dioxide. NASA scientists hope that their latest rover, Curiosity, will get them some answers. Launched on the Atlas V rocket in November 2011, Curiosity finally completed its 160 million-mile journey nearly nine months later, landing in Mars s Gale Crater on August 6 of this year. We chose the landing site very carefully, recalls Wessen, namely because of the area s large deposit of stratified bedrock. This bedrock, Wessen explains, has manifold benefits. Unlike loose rock, scientists can be sure that it was formed at the location where they found it, and being that it s stratified, they know that the deeper they drill, the farther back in time they go. The bedrock will enable us to sample the conditions on Mars as they existed billions of years ago, he says. We re going through time to see how its weather and its overall environment have changed. Curiosity is perfect for the job. Unlike its predecessors, Sojourner and Opportunity, which carried only 11 pounds of scientific instruments, Curiosity totes an impressive 165 pounds of investigative gear. In almost every conceivable way, NASA s latest rover is a feat of engineering. Designed to function as a mobile laboratory, Curiosity allows scientists on Earth to collect samples and analyze them on the surface of Mars; a handy feature considering that we re not yet able to retrieve the vehicle. Furthermore, Curiosity utilizes what essentially amounts to an outer space telecommunications system to relay analytical data and high-definition images back to NASA, and it does so at the high-volume rate of 30,000 bytes per second.

The next frontier

In essence, we re witnessing the next frontier in our exploration of the next frontier. And as outer worldly as it may seem to the lay person, Wessen is quick to remind us just how close to home these mission objectives remain. While we re trying to answer different questions in each of these missions, ultimately we want to know how life started on Earth, says Wessen. We think that by exploring planets like Mars, where there may have been life at one time, we can get closer to unlocking these mysteries. michael.williams@erickson.com

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