From Exploring Caves to Exploring Europa

[Cheryl Jones]

Nov. 10, 2006, 1:00AM
TESTING THE WATERS
An explorer and his dream
Engineer hopes to take a robot from deep water to deep space — and find proof of life there

By MICHAEL RAY TAYLOR
For The Chronicle

As an explorer, Bill Stone is used to setting foot where no human has. He's discovered deep cave systems in Mexico and mapped underwater labyrinths in Florida.

But as an engineer, Stone dreams of exploring the final frontier — and bringing back to Earth solid proof of alien life.

For four days in October, he and his Austin-based company tested a robot called DEPTHX — short for Deep Phreatic Thermal Explorer — that may one day become Stone's surrogate in space.

It was funded under a program designed to send an intelligent underwater robot to an ocean of liquid water believed to exist beneath the icy crust of Europa, a moon of Jupiter. Operating alone, with no instructions from Earth, such a robot would have to explore outward, mapping as it went, making educated guesses on where to find life, then testing to see if life is there.

DEPTHX may be the smartest NASA robot ever built, in terms of raw computing power and freedom from human controllers. But at a time when the agency is abandoning robotic projects in order to pay for a new manned space vehicle, it may never leave this planet.

Even so, it is poised to make significant discoveries here on Earth and to further the spacefaring ambitions of its creator.

"DEPTHX is to existing underwater vehicles like cave-diving is to open-water diving," Stone said. "It represents a new level of sophistication that had to be designed and built from scratch."

Stone, the project's principle architect and the founder of Stone Aerospace, often uses caving and cave-diving analogies when speaking about space. He's one of the world's best-known cave explorers and cave divers. The 53-year-old engineer has designed and patented many of the specialized devices now used in the dangerous pursuit of extreme cave diving.

The seed of an idea
In 1999, Stone was trying to create an accurate map of Florida's Wakulla Cave, one of the longest and most complex underwater caves known. Because divers in caves have to carry enough air to get in and out of passages, the time-consuming act of mapping complex systems in any detail had always been difficult. Stone's solution, developed with electronics engineer Nigel Jones, was to mount a sonar system onto an underwater scooter, called the Digital Wall Mapper, that would create a detailed 3-D map as the divers were pulled along.

"Nigel and I were having coffee one morning near the end of the Wakulla project," Stone recalled. "We were wondering about what to do next. I said, 'You know, this thing has enough computing power, we could probably make it completely autonomous.'"

Stone envisioned a device turned loose in the honeycombed chambers of aquifers that were otherwise inaccessible to divers. But he did nothing more with the idea until a friend told him years later that NASA was soliciting ideas for a "hydrobot," or underwater robot, that might one day search for life on Europa.

"Bill realized that he needed to bring in some people with more experience in robotics to make it work, so he contacted us three years ago," said project scientist George Kantor, of Carnegie Mellon University. Kantor helped assemble a team from the university's Robotics Institute to create software compatible with Stone's designs.

NASA awarded the proposal a $5 million Phase I development grant under a program called Astrobiology Science and Technology for Exploring Planets, or ASTEP. Eight months after the design was complete, the robot was ready for testing at the University of Texas' Applied Research Laboratories in Austin, in advance of its first planned field test in the world's deepest water-filled sinkhole in Mexico.

If all went well with the field tests, Stone said, NASA officials agreed to fund a second-generation vehicle that would be tested in Lake Vostok, a vast expanse of freshwater trapped beneath miles of ice in Antarctica.

Robot hits roadblock
But that was before the announcement this spring that NASA was pledging billions to develop a next-generation vehicle to replace the aging space shuttle. ASTEP was one of many NASA science programs falling under the budget ax this summer, leaving Stone with a nearly finished robot facing an uncertain future.

"NASA told me I had the best project in the nation for Phase II funding," he said. "And in the next breath they said, tough luck."

John D. Rummel, NASA's senior scientist for astrobiology, said Tuesday that the situation may not be as grave as Stone fears. Despite what Rummel termed a "significant decline" in overall agency spending for astrobiology, he anticipates that current projects like DEPTHX will be able to vie for renewed support in upcoming competitive selections.

A round of testing
Most of the first morning of testing at the ARL last month was stalled by various fault indicators. But once software glitches were fixed, the robot began to explore and map the 700,000-gallon tank as if it had a mind — and onboard science lab — of its own.

The team plans to take the robot to Mexico this winter, where Stone predicts it will discover new microbial species in the deep and largely unexplored hydrogen sulfide-rich waters of the Zacaton sinkhole. He has not yet given up on NASA paying for a DEPTHX trip to Antarctica, but he is looking at other possible funding sources.

It wasn't the first time the space agency let Stone down.

In 1989, he and 59 other scientists made it through the astronaut selection process to the point where intense psychological testing kicked in as NASA narrowed the field to 19. Stone says the agency determined he was "too independent" to work well with a team.

Now, he wants to take that independence and drive to the moon, to lead a privately funded mining effort.

"Apollo proved that you can go to the moon in the same way Lewis and Clark proved you could you go west," Stone said. "But then it was up to private industry to actually develop the west, for profit. That time has come with the moon."
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ABOUT DEPTHX
The Deep Phreatic Thermal Explorer has 30 onboard computers.

• The top of the prototype resembles a slightly flattened pumpkin, eight feet in diameter.

• Its bottom half , bristling with sensors and thrusters, looks like something out of Star Wars .

• The saucer-shaped machine can move in any direction — forward, sideways, backward, up or down.

• DEPTHX also rotates as it goes, firing sonar in all directions to get a complete map of its environment.
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http://www.chron.com/disp/story.mpl/met ... 15216.html

[hewhocaves]

ah... a mike taylor article... anyone know how mike is these days?