Rain is the last thing Carnegie Mellon University researchers had in mind when they designed their latest robot, named Zoe.

	Bob Donaldson, Post-Gazette Senior research programmer Michael Wagner fine tunes the computer programming for the Zoe robotic vehicle in preparation for its trip to Chile's Atacama Desert for testing. Click photo for larger image.

Fenders and splash guards won't do Zoe much good once it arrives in one of the driest places on Earth, Chile's Atacama Desert. But they might have helped one day last week, when Carnegie Mellon planned to demonstrate the four-wheeled, solar-powered rover at the old LTV site in Hazelwood.

The event was canceled because of rain.

The team will be crating the 9-foot-long, 6-foot-wide robot this week, preparing to ship it to Antofagasta, Chile, next week. Beginning next month, it will look for signs of life in the northern Atacama desert.

The three-year, $3 million Life in the Atacama project, which began last year, is sponsored by NASA to develop technologies for automated searches for life on Mars and other planets. Large stretches of the Atacama, where fog is the major source of precipitation, appear devoid of life; if machines can find life in the Atacama, the thinking goes, they might have a chance of finding life on Mars, if it exists there.

Nathalie Cabrol, a planetary scientist at NASA's Ames Research Center in California and the lead scientist for the Atacama project, noted the two Mars Exploration Robots now at work on the Red Planet have proven adept at mapping and geologic studies. But it remains an open question whether a machine can unambiguously detect life in such a barren environment.

The Robotics Institute is developing the robot and the robotic techniques for a search-for-life mission, while Carnegie Mellon's Molecular Biosensor and Imaging Center has developed a device that uses natural fluorescence and fluorescent dyes to find minute signs of life on rocks.

Zoe -- Greek for "life" -- will undergo testing once it arrives in Chile. It will then perform traverses in search of life Sept. 12-18 and Oct. 3-9 at two sites -- one site typical of the relatively wet coastal range and another site in the bone-dry interior.

Researchers at an operations center in Pittsburgh will direct the search remotely; members of the science team here will evaluate the scientific data transmitted by Zoe, much as they would for an actual space mission.

Though the science team will direct Zoe to places of interest, the robot itself will make most of the detailed decisions, such as how to get from place to place, and will be able to travel a kilometer or more without human intervention.

This will be the team's second sojourn in the desert, but the first for Zoe. With a top speed of 2.2 miles an hour, Zoe won't break any speed records, but that's four times faster than its robotic predecessor, Hyperion, said David Wettergreen, associate research professor at the Robotics Institute and project leader. New solar panels also will double its power.

A robot that moves faster from place to place, he explained, can spend more time at each spot performing its life-seeking tests.

Unlike Hyperion, Zoe will also carry the experimental fluorescent imager on board. The device has been redesigned to include an ultraviolet flash unit, which may allow it to detect faint fluorescent signals during the day, said Alan Waggoner, director of the biosensor center. Earlier versions, which used a weaker LED light, would have operated only at night, when the robot can't move.

Last month, at a project workshop, Cabrol suggested expanding the project goals to encompass President Bush's initiative for human exploration of the moon and Mars.

"We know that humans are better than robots, at least for now, at finding things, especially life," she said. But the project should try to document the limits for both humans and machines in detecting life on Earth.

The project might also address such issues as whether humans or machines are more likely to contaminate other worlds with life they carry with them. And researchers should examine how humans and machines can best work together in searching for life, she added.

The science team will guide Zoe remotely from Pittsburgh using EventScope, a computer tool developed by Carnegie Mellon's Studio for Creative Inquiry that enables scientists and the public to experience the Atacama environment through the eyes and various sensors of the rover.