Researchers Take Large Strides Toward Creating Life-Seeking Robot
Hyperion, an autonomous, solar-powered robot and its advanced life-detection and geologic instruments, developed by Carnegie Mellon 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. It spent a month in Chile's Atacama Desert this summer with researchers from the university and NASA's Ames Research Center. They used the robot 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.
Hyperion traveled farther and collected more data while operating autonomously than any planetary rover tested to date. The team expected Hyperion could travel 10 kilometers (6.2 miles) autonomously and collect 10 complete sets of data from each of its instruments this year. Ultimately the robot traveled more than 20 kilometers and produced 27 data sets. Its instruments' direct method of detecting life promises to represent the next generation of life-seeking technology.
The robot was also able to operate autonomously for a longer distance than previous planetary rovers. "Today, most rovers average a few meters of motion per communication with their operators," said David Wettergreen, Robotics Institute research scientist. For example, in 84 days the Mars Sojourner rover traveled about 300 meters, a few meters at a time. "We are working toward 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 more than a kilometer for each communication with scientists."
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. Wettergreen leads robotics research and field experimentation, while Nathalie Cabrol, a planetary scientist at NASA Ames Research Center and the SETI Institute, leads the science investigation for the Atacama project. Alan Waggoner, director of the Molecular Biosensor and Imaging Center (MBIC) in the Mellon College of Science, is principal investigator for the companion project in life-detection instruments.
Waggoner said the dual approach to life detection they've developed was highly effective during the first expedition to the Atacama. One approach involves exciting any chlorophyll that might be present by shining specific wavelengths of light known to be absorbed by chlorophyll or its secondary pigments and detecting the resultant fluorescent signal they emit.
The second aspect requires 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 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.
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 experimentseverything from determining the efficiency of advanced technology solar arrays to characterizing wheel traction in desert terrain and 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.
"Life in the Atacama" 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.