Four years ago, NASA was rushing at Mars with no less than a dozen missions. A primary objective was to bring samples of Martian soil to Earth by 2008. But late in 1999, the Mars Climate Orbiter disappeared, followed 71 days later by the Mars Polar Lander. Getting rocks back from the Red Planet was postponed until at least 2014, and that was a source of both disappointment and relief to Carlton Allen.
Allen is NASA's curator of astromaterials at the Johnson Space Center in Houston. On the one hand, he's dying to get hold of some Mars rocks. On the other hand, he believes that Earth is not ready to receive anything from Mars that could harbor alien life-forms. His fears are based partly on new discoveries from places like Antarctica and the bottom of the Pacific Ocean that show small life-forms like bacteria have found ways to thrive in extreme places. He also worries because no one has a very good idea of just how we might seal off Martian rocks from the rest of us.
At the same time, scientists face the challenge of keeping Earth and its many life-forms from contaminating whatever we bring back from Mars. As NASA's planetary protection officer John Rummel puts it, you don't want to declare you've found a Martian microbe "when all you've found is life from Florida or Texas." That means a successful containment lab must combine biosafety technology developed for germ warfare with clean-room technology developed for computer chips. "We have not demonstrated that we can integrate those functions to meet planetary protection requirements," Allen says bluntly.
Two hundred miles west of Houston, in San Antonio, Scott Shearrer lays his big blue space suit down on the gray floor. The suit is designed for dangerous inner space, not outer space. Shearrer, an affable Texan with a trim moustache, a passion for barbecue, and a ready smile, checks for tiny rips in the fabric. Finally satisfied that the suit is airtight, he pulls it over his legs and puts on a radio headset.
