Is This the Machine That Will Finally Find Life On Mars?

And now all the snafus of the past few days suddenly make sense. The Pittsburgh scientists didn´t send Zo into brutal terrain because they´d gotten
sloppy or cavalier. They meant to steer the ´bot along the most passable route-only they were living in a parallel universe. They thought Zo was in a valley with clear sailing to the west, when it was actually in another valley nine miles away. When the Pittsburgh team told it to head west, it ran smack into the foothills between the two valleys.

Young techies don´t tend to be especially forgiving of other people´s glitches. But as comprehension sank in, so did an appreciation for the science team´s plight. "When you´re in a bunch of rounded hills like we´ve been in," Smith says, "one peak looks just like another."

When the scales fall from the Pittsburgh team´s eyes later that evening, the stakes are higher and the casual locker-room atmosphere is notably absent.

Remote Brain, Desert Body

All along, the Pittsburgh team has appreciated that it is a brain in a jar, sending commands to an entity whose location it can only infer. Zo´s field season consists of three mini missions that start from different "landing sites" in the desert. Just as NASA scientists have only an approximate idea where their spacecraft will land on Mars, when Zo is moved to a new site in the Atacama, the Pittsburgh team isn´t told exactly where it is. All they know is that the ´bot is somewhere within a red circle drawn on a map.

Because Mars lacks the satellites necessary for GPS to work, the Pittsburgh team has to locate Zo the old-fashioned way, triangulating its position using identifiable landmarks. To do this, the team constantly compares two images that are projected on screens in the front of the room: Zo´s most recent end-of-day panoramic photo, and a satellite image of the section of the Atacama that contains the current "landing" site. They identify three prominent points on the panoramic image and then locate those same points on the orbital map. When the position they choose for Zo on the orbital map has the same geometry relative to the three chosen map points as Zo does to the three pan-photograph points, then the robot has been found in the real world. Or, if they´re not careful, lost in the real world.

James Dohm is the team´s lead triangulator. During field operations, he spends his days and nights hunched over a laptop, mapping geologic "units" onto satellite imagery of the Atacama-a reprise of the countless hours he´s spent producing five published maps of Mars. "I´ve had a lot of all-nighters," he says.