NASA-funded robotic sub finds bottom of world's deepes...( PITTSBURGH -- A robotic vehicle design...)

PITTSBURGH -- A robotic vehicle designed for underwater exploration plunged repeatedly into the depths of Mexicos mysterious El Zacatn sinkhole in late May, finding its previously undiscovered bottom 318 meters below the surface and generating a sonar map of its inner dimensions. The vehicle employed autonomous navigation and mapping systems developed by Carnegie Mellon Universitys Robotics Institute.

During a two-week NASA-funded exploration led by Bill Stone of Stone Aerospace, the Deep Phreatic Thermal Explorer (DEPTHX) revealed that the geothermal sinkhole, or cenote, did not have a tunnel or any other obvious underwater connections with neighboring cenotes in the Mexican state of Tamaulipas. It also obtained numerous samples of water and the gooey biofilm coating the cenotes walls.

"Were very pleased about the performance of the DEPTHX system," said David Wettergreen, an associate research professor who headed Carnegie Mellons contingent of the research team. "We hit our technical objectives in creating a system that could explore and map autonomously."

In addition to gathering information regarding geothermal sinkholes, DEPTHX tested technologies and methods that might be useful in other underwater explorations, including the long-term possibility of exploring the oceans hidden under the icy crust of Europa, one of Jupiters moons. For the near term, NASA recently approved a project that will use these technologies to explore underneath the ice of West Lake Bonney in Antarcticas Taylor Valley.

The DEPTHX vehicle, 2.5 meters in diameter, included 56 sonars that the Carnegie Mellon team used to determine the location of the vehicle as it explored the cenote. It also used the sensors to create maps of the sinkholes interior via a technique called simultaneous localization and mapping, or SLAM. Prior to the DEPTHX field experiment, SLAM had been used for navigating in buildings and mines, but had never operated in an underwater environme
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Contact: Byron Spice
bspice@cs.cmu.edu
412-268-9068
Carnegie Mellon University
31-May-2007