Robot to explore world's deepest sinkhole

Scientists will try to chart one of the world's deepest oceanic sinkholes this week by deploying a robotic submarine in a mission that if successful, could one day be helpful in exploring other planets.

The NASA-funded robot, called the Deep Phreatic Thermal Explorer (DEPTHX), will be deployed Tuesday on a two-week mission into Mexico's El Zacaton geothermal sinkhole, or cenote, which is more than 282 meters deep and pitch black. No human has ever reached its bottom, but one diver has died in the process. Scientists hope that the expedition will produce greater understanding of the sinkhole's dimensions, geothermal activity and ecosystem.

About 2.5 meters in diameter, the submarine runs autonomously in uncharted and mapped terrain by relying on an array of 56 sonar sensors, including depth, velocity and inertial sensors. Software developed by a team at Carnegie Mellon University controls the sub's movement and creates maps of its surroundings. "DEPTHX is unique among autonomous underwater vehicles in its ability to navigate untethered in complicated, sometimes closely confined underwater spaces," according to Carnegie Mellon's Robotics Institute.

The mission will be to explore the sinkhole's uncharted territory and get 3D maps of its caverns and mines. The robot will also extract water samples and earth samples from its walls.

The Mexico mission will be the third test of DEPTHX, which was designed and built by Stone Aerospace. Other researchers working on the project include scientists from the Southwest Research Institute, University of Texas at Austin, Colorado School of Mines, and NASA Ames Research Center. Carnegie Mellon developed the navigation and guidance software for the robot.

The scientists ultimately hope that the technologies behind DEPTHX will be used in other underwater missions, as well as to explore oceans hidden under the icy crust of Europa, one of Jupiter's moons.