PITTSBURGH — An autonomous, solar-powered robot and its advanced life-detection and geologic instruments, developed by Carnegie Mellon University researchers, have both exceeded expectations in the first phase of a three-year effort to develop and deploy a robotic system that may some day enable other rovers to search for life on Mars.
The robot Hyperion, operating in Chile's Atacama Desert, traveled farther and collected more data while operating autonomously than any planetary rover tested to date. Moreover, its instruments' method of detecting life directly promises to represent the next generation of life seeking technology. Hyperion spent April in the Atacama, directed by a team of university and NASA Ames Research Center scientists. The team used Hyperion as a platform for conducting experiments and gathering information that will help them to design a system especially suited to looking for life in a desert environment. The goal of the NASA-funded "Life in the Atacama" project is to create robotic technologies and instruments broadly applicable to the search for life, defined by the team as robotic astrobiology, while conducting a scientific investigation of the unknown distribution of life in the Atacama. The Chilean desert is often described as analogous to Mars because of its aridity, soil composition, and extreme UV radiation.
The principal investigator on the project is William L. 'Red" Whittaker, Fredkin Research Professor at the university's Robotics Institute. David Wettergreen, a research scientist at the institute, leads robotics research and field experimentation. Nathalie Cabrol, a planetary scientist at NASA Ames Research Center and the SETI Institute, leads the science investigation for "Life in the Atacama." Alan Waggoner, director of the Molecular Biosensor and Imaging Center in the university's Mellon College of Science is principal investigator for the companion prject in life-detection instruments.
Waggoner said the dual approach to life detection they've developed proved highly effective during this first expedition to the Atacama. One approach is to excite any chlorophyll that might be present by shining specific wavelengths of light known to be absorbent by the chlorophyll or its secondary pigments and detecting the resultant fluorescent signal they emit.
The second aspect involves applying dyes that bind to each of the four major classes of macromolecules found in cells. The dyes are designed to fluoresce only when they bond to specific molecules of nucleic acid, protein, lipid or carbohydrate.
"This system will have considerable power to actually detect the components of life, instead of simply providing evidence that an environment exists that supports life," Waggoner explained. "These methods correlate the presence of the four essential components of living cells at the same location, a strong indication of life. We believe they represent the next generation of life-detection technology."
"This project is seeking genuine discoveries about the evolution and survival of life in one of Earth's most extreme environments, while preparing us for planetary missions," said Cabrol. "During the site selection process, the Chilean science team made important observations about life habitats that are now being analyzed and could pertain to this category of new knowledge."
As part of their robotics research, Wettergreen said the team deployed Hyperion as a functional baseline and conducted experiments to develop requirements for a robot able to study desert life. "We conducted a dozen major experiments--everything from determining the efficiency of advanced technology solar arrays to characterizing wheel traction in desert terrain, to calibrating sensors and instruments under harsh environmental conditions," Wettergreen said.
Based on what they've learned from this year's work, he and his colleagues will create a robot attuned to the Atacama, particularly in terms of its ability to access important science sites and to execute the long traverses that will allow scientists to map the gradient of life between coastal regions and the Atacama's hyper-arid interior.
This year, the team expected Hyperion could travel 10 kilometers (6.2 miles) autonomously and collect 10 complete sets of data from each of its instruments. Ultimately the robot traveled over 20 kilometers and produced 27 science data sets. In addition Hyperion was able to operate autonomously for a longer distance than previous planetary rovers. "Today," said Wettergreen, "most rovers average a few meters of motion per communication with their operators." For example, in 84 days the Mars Sojourner rover traveled about 300 meters, a few meters at a time. "We are working towards a one-command per one-kilometer of traverse, and we accomplished it once during this field season. When our robot is deployed in 2004, the goal will be to have it consistently travel and sample over a kilometer for each communication with scientists."
The "Life in the Atacama" project is part of NASA's Astrobiology Science and Technology for Exploring Planets (ASTEP) program, which concentrates on understanding the limits of life on Earth while pushing the limits of technology for planetary exploration. It is funded with a $3 million, three-year grant from NASA to the Robotics Institute. Scientists at the MBIC have a separate $900,000 NASA grant to develop the fluorescence-based instruments that the robot will eventually incorporate.The Life in the Atacama team has spent the summer organizing and analyzing the extensive data sets collected during field experimentation. The entire team will meet in Pittsburgh for a three-day workshop July 28-30, where they will present scientific interpretation, review technical insights, and plan activities for the 2004 and 2005 field seasons.
For further information about Life in the Atacama visit: http://www.frc.ri.cmu.edu/atacama