The Deep Phreatic Thermal Explorer (DEPTHX) is an autonomous underwater vehicle designed and built by Stone Aerospace, an aerospace engineering firm based in Austin, Texas. It was designed to autonomously explore and map underwater sinkholes in northern Mexico, as well as collect water and wall core samples. This could be achieved via an autonomous form of navigation known as A-Navigation.[clarification needed] The DEPTHX vehicle was the first of three vehicles to be built by Stone Aerospace which were funded by NASA with the goal of developing technology that can explore the oceans of Jupiter's moon Europa to look for extraterrestrial life.[1][2][3]
DEPTHX was a collaborative project for which Stone Aerospace was the principal investigator. Co-investigators included Carnegie Mellon University, which was responsible for the navigation and guidance software, the Southwest Research Institute, which built the vehicle's science payload, and research scientists from the University of Texas at Austin, the Colorado School of Mines, and NASA Ames Research Center.[4]