Bill Stone began Stone Aerospace as a part-time consulting business in 1999, at which time he was working at the National Institute of Standards and Technology. At the time, Stone already had an extensive background in underground and underwater exploration, which had led him to develop several technologies to further human exploration capabilities. This background, and in particular the success of the Wakulla II Project in Wakulla Springs, Florida, which employed Stone's human-navigated digital wall mapper, lead to inquiries as to whether it would be possible to design an autonomous underwater vehicle, which could explore on its own, making exploration possible where it was not safe or possible for human divers to go. After submitting several proposals to NASA, in 2003 DEPTHX was funded. Shortly thereafter Stone's Piedra-Sombra Corporation began doing business as Stone Aerospace in Del Valle, Texas. After the successful autonomous exploration by DEPTHX of several cenotes in Mexico, NASA then funded the ENDURANCE Project, which spent two seasons exploring frozen-over lakes in the Dry Valleys of Antarctica. Project VALKYRIE was awarded NASA funding in 2010, and is currently in the early stages of development.
DEPTHX was a NASA-funded 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. The DEPTHX vehicle was a fully autonomous underwater vehicle outfitted with scientific sampling equipment designed to expand upon the limits of human underwater exploration, and was successfully tested over two field seasons in cenotes in northern Mexico. Among its most notable accomplishments were the discovery of at least three new divisions of bacteria (the first such discovery by a robotic vehicle) and the first use of three-dimensional simultaneous localization and mapping (SLAM).
The NASA-funded ENDURANCE project built upon the successes of DEPTHX. The DEPTHX vehicle itself was reconfigured to create ENDURANCE, with a new science payload and new navigation systems added to meet the challenges particular to the frozen-over environment in Antarctica, where it spent two field seasons. The principal investigator for ENDURANCE was Dr. Peter Doran of the University of Illinois at Chicago. Co-investigators were Stone Aerospace, Dr. John Priscu of Montana State University, and NASA Ames Research Center. ENDURANCE spent two seasons exploring West Lake Bonney in the Dry Valleys, autonomously collecting aqueous chemistry data as well as making high-resolution maps of the lake floor and the portion of Taylor Glacier which interfaces with the lake. The results are believed to be one of the most comprehensive three-dimensional biogeochemical maps of any lake on the planet. The project was the subject of an episode of National Geographic Explorer in 2010 which focused on the goal of discovering life on Jupiter's moon, Europa.
Stone Aerospace's VALKYRIE Project received its Phase II funding in May 2011. VALKYRIE will be an autonomous cryobot which will build on one of the primary goals of the ENDURANCE vehicle, which is to investigate the possibility of exploring the hypothesized oceans of frozen-over moons in our solar system, such as Europa, in the search for extraterrestrial life. The VALKYRIE vehicle will get its melting power from a high-energy laser, which itself would remain on the surface. The laser beam will travel down a long fiber optic cable (where the beam would then be amplified) which would feed out as the vehicle melts through the ice surface. Stone revealed this novel approach at NASA's Astrobiology Science Conference in April, 2012, and plans are underway to test the technology at Matanuska Glacier in Alaska in 2013.
- Stone Aerospace History. Stone Aerospace. Retrieved: 6 March 2012.
- NASA Robot Completes Test Drive of Exploration Capabilities PR Newswire. 31 May 2007
- Antarctic diving robot practices for Europa. MSNBC Today Tech. 9 April 2010.
- Stone Aerospace wins Phase 2 funding for Project VALKYRIE. Stone Aerospace. 18 October 2011.
- About the DEPTHX Project. Carnegie Mellon Field Robotics Center. Retrieved 25 March 2012.
- Robot Subs in Space. Popular Science. 1 Feb 2007.
- A comparative molecular analysis of water-filled limestone sinkholes in north-eastern Mexico. Wiley Online Library. 25 August 2010.
- DEPTHX (DEep Phreatic THermal eXplorer). Stone Aerospace. Retrieved 25 March 2012.
- ENDURANCE 2009 Field Season. Stone Aerospace. Retrieved 29 March 2012.
- ENDURANCE(Environmentally Non-Disturbing Under-ice Robotic ANtarctiC Explorer). Stone Aerospace. Retrieved 29 March 2012.
- Journey to an Alien Moon. National Geographic. Retrieved 29 March 2012.
- Cryobots Could Drill Into Icy Moons With Remote Fiber-Optic Laser Power. Wired magazine. 19 April 2012.