PITTSBURGH-Researchers from Carnegie Mellon University's Robotics Institute have deployed a four-wheeled robot named Nomad to a site in Antarctica, where it will autonomously search for meteorites and classify them in the field with scientific instruments contained in a newly developed manipulator arm. The expedition marks the first time a robot will be used to discover extraterrestrial material that has fallen to Earth and could serve as a prototype for future scientific missions to Mars and the Moon. The Nomad research program and the expedition are funded by grants from the Cross Enterprise Technology Development Program of NASA's Office of Space Science. Additional support for a related public outreach program comes from the Heinz Endowments, the Henry C. Frick Fund of the Buhl Foundation and the Grable Foundation, all in Pittsburgh.

The expedition is the result of a collaboration between Carnegie Mellon researchers and the National Science Foundation's (NSF) Antarctic Search for Meteorites (ANSMET) program, which funds the work of ANSMET scientists through its Office of Polar Programs. Since ANSMET was established in 1976, its members have collected more than 10,000 meteorites during their annual expeditions to Antarctica. They subsequently have been made available to the world's scientists for study.

The robotic search for meteorites is taking place at Elephant Moraine, a remote area in eastern Antarctica, 160 miles northwest of the United States base at McMurdo Station. Nomad and the Carnegie Mellon/ANSMET team were transported to the site from NSF's staging ground at McMurdo via light aircraft and helicopter.

Nomad will perform autonomous searches and classification of rock samples at Elephant Moraine in an effort to discover meteorites. Its search will include driving, looking, choosing and testing to select meteorite candidates it encounters in the area. The robot will use high-resolution imagery and spectroscopy to gather scientific data about the rocks it finds. Its arm will enable precise placement of the scientific instruments on the rocks it chooses to study.

The ANSMET member of the field team will serve as a guide to the region and collect any meteorites that Nomad successfully locates. The expedition will last about three weeks, depending on the weather.

Elephant Moraine looks like a small elephant with a very long trunk. It's considered to be one of the more important sites for meteorite discovery, with nearly 2,000 specimens recovered during seven previous visits, including the first meteorite identified as definitely being from Mars. This year's expedition takes place near the end of the "elephant's trunk," which was last searched in 1979.

The principal investigator on the Nomad project is William L. "Red" Whittaker, the Fredkin research professor and founder of the Field Robotics Center at Carnegie Mellon's Robotics Institute. The project manager is Robotics Institute Systems Scientist Dimitrios Apostolopoulos.

A six-member Carnegie Mellon team will be supporting the experiments on the ice. The group includes Robotics Institute doctoral students Stuart Moorhead, Liam Pedersen and Kim Shillcutt, Mark Sibenac and Michael Wagner, who are studying for master's degrees in electrical and computer engineering, and Ben Shamah, a senior research engineer at the Robotics Institute.

The head of the ANSMET program is Ralph P. Harvey, assistant professor of geological science at Case Western Reserve University. His associate, John Schutt, will be collecting Nomad's meteorite choices in the field. "This expedition will showcase the ability of a robot to discover meteorites, distinguish them from surrounding rocks and do it in an autonomous, self-reliant, self-contained manner," said Whittaker. "The breakthrough technologies are robotic classification and search. Humans classify every time they sort pennies from nickels, and they search every time they lose their car keys. But these are new skills for robots. Classification and search both must succeed for the autonomous meteorite discovery to succeed. Until now, explorative robots have taken pictures, gathered data and returned what they viewed to scientists who made judgments and decisions. This time Nomad will make its own judgments and inferences about the rocks that it encounters."

Nomad has been programmed with navigation strategies for driving. It will move in patterns similar to those people use when they're operating a lawn mower. As it moves, machine vision will enable it to search for rocks distinguished by their dark color against the white ice background. Then, the robot's high-resolution camera can zoom in on a rock, determining size and color as evidence that it's a meteorite. As Nomad explores an area, it must choose which rocks to examine and in what order. It will have to decide whether it should drive, use its arm or employ both capabilities to reach its goal.

"The compelling element of this expedition is the prospect of meteorite discovery by a robot," Apostolopoulos said. "Nomad will demonstrate for the first time the ability of a science robot to autonomously search for and distinguish meteorites from terrestrial rocks. Robotic technologies demonstrated by this project could set a new precedent on the state-of-the-art in space robotics and impact how missions to the planets are designed and carried out."

As the expedition in Antarctica unfolds, the public will be able to follow the action on the Web. Southwestern Pennsylvania K-12 science students and teachers will follow Nomad's adventures in real time through Carnegie Mellon's interactive Web site known as the Big Signal Project. This is Nomad's third trip to a locale on Earth analogous to an extraterrestrial world. In the summer of 1997, it made an unprecedented 130-mile trek through the Atacama Desert in Chile while being teleoperated by researchers in Pittsburgh and at NASA's Ames Research Center. Last winter, it was taken to Patriot Hills in the Chilean section of Antarctica, where its navigation capabilities were tested under polar conditions.

Experience Nomad's robotic search for Antarctic meteorites: The expedition: http://www.ri.cmu.edu/~meteorobot2000

Education and outreach: http://www.bigsignal.net