Chile Desert to Prepare Robot for Life on Mars
for National Geographic News
|April 25, 2003|
Scientists on the prowl for life on Mars have trained their sights on the parched Atacama Desert of northern Chile. Scientists believe that if their high-tech robotics succeed in their quest to find life in the Earth's most inhospitable deserts, they may also be able to find life on Mars.
David Wettergreen, a research scientist at Carnegie Mellon University's Robotics Institute in Pittsburgh, Pennsylvania, described the Atacama as "the most arid desert on Earth. It is what scientists call an end member [ecosystem] in that it has the lowest organic content of anywhere on Earth."
In the Atacama desert, intense ultraviolet radiation from the sun and strong soil oxidants combine to quickly break down organic materials. Scientists believe a similar combination found on Mars could also possibly break apart and isolate any life forms that once existed thereor still do.
So Wettergreen and his colleagues are using the Chilean desert as a Mars proving ground to develop and test a robot equipped with a suite of sensing and imaging technologies designed to take pictures of life on the red planet. The technologies would ultimately be transferred to surface rovers carried on future Mars-bound space missions.
The project is funded by U.S. $3 million in grants from a NASA program dedicated to astrobiology, or space-based life, exploration. The first of three field expeditions departed for the Chilean desert earlier this month. Over the next three years, the researchers hope to improve on the technologies designed for Mars exploration.
Today's robots are able to determine what the environment is like by taking pictures, among other means. "Tomorrow we need to have rovers that are more capable," said Nathalie Cabrol, a planetary scientist at the NASA Ames Research Center in Moffett Field, California, who is leading the team for the science investigation of the Atacama.
Hyperion and Analogs
The next generation rovers will use technologies developed for Hyperion, a 6.5 foot (2 meter) wide and 6.5 foot (2 meter) long robot with a 38 foot (3.5 meter) square solar panel for a roof. Named for the Greek word meaning "he who follows the sun," Hyperion is an autonomous robot. It is programmed to operate independently and can determine when to point its solar panel towards the sun.
Hyperion was originally tested on Devon Island in the Canadian Arctic in 2001. During that trial, the robot successfully kept its solar panel pointed towards the sun as it traveled for 24 hours along a 3.8-mile (6.1-kilometer) circuit over hilly, rocky terrain. The vehicle returned to its starting point with a set of fully-charged batteries.
Scientists consider the cold, barren, and rocky terrain of Devon Island to be analogous to the terrain on Mars. The island is regularly invaded by researchers with the Mars Society, an Indian Hills, Colorado-based organization dedicated to exploring and ultimately settling Mars.
No single landscape on Earth can ever replicate the Martian planet, Cabrol said. That helps explain why scientists researching Mars exploration frequent places as diverse as the Canadian Arctic and Chilean desert. "We are going to different places depending on what questions we want addressed, so we are addressing very specific questions."
On Devon Island, researchers tested Hyperion's ability to navigate terrain similar to that found on Mars. In the Atacama, researchers will focus on measurements and experiments with the robot's hardware and software components, including its ability to see and test objects of interest for signs of life.
Life Sensors and Autonomy
Alan Waggoner, a biological scientist with Carnegie Mellon's Molecular Biosensor and Imaging Center, is leading the development of special fluorescent dyes and automated microscopes that Hyperion will eventually use to find microscopic forms of life.
"The idea is we will be able to put a very fine mist on rocks or soil that will stain microorganisms and biofilms with dyes that will make themselves visible for microscope analysis," said Waggoner.
The fluorescent dyes are activated when they bind to certain types of molecules commonly found in living organisms such as proteins, DNA, lipids, or carbohydrates, explained Waggoner. Bound to their targets, the dyes glow a specific color when illuminated with artificial light.
"You'd get false signal if you got any one of the colors. But if you saw all four coming from the same spot you'd be certain it is a microbe or living cell in the way we know life is," said Waggoner. The imaging components of this technology will be tested this year in Chile. The entire system is slated to be operational by 2005.
Hyperion will also travel about six miles (ten kilometers) through the desert this year, as the researchers test the robot's ability to function autonomously. Back in the U.S. the researchers will use their collected data to re-work and re-write the computer software that gives Hyperion its independence.
"It can navigate. Now it needs [the ability] to reason about communication as well as science instruments: How to use them, when to deploy, how to schedule power usage and timing so it has all the resources it needs when called on," said Wettergreen.
Researchers will develop later generations of the robot for testing in 2004 and 2005, based on this year's desert trials.
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