To Design Miners' Escape Pod, NASA Thought Small

(Oct. 9) -- Clinton Cragg is a NASA engineer on a troubleshooting safety team set up in the wake of the 2003 Space Shuttle Columbia disaster. He had spent much of his professional life in the Navy, where he served as a submarine captain, accustomed to living in confined space.

So when the Chilean rescue authorities settled on a plan for reaching the 33 miners trapped 2,400 feet below a desolate desert, but needed a contraption to bring them to the surface, Cragg would become the perfect man to pitch in.

It had to be the smallest possible vehicle for the job, a capsule that would fit into a hole the size of a bicycle tire, with no wasted space for luxury, no elbow room for comfort.

When Cragg turned over the design elements to the Chilean navy, which refined them and built the capsule, the rescue craft that emerged looked as if it belonged on a science fiction movie's drawing board. Shaped like a cigar canister, with a drop-through escape hatch at the bottom, the capsule is designed to bring all 33 men up, one at a time, on a 20-minute ride from the hellhole where they have been trapped since Aug. 5. It is 13 feet long and weighs 926 pounds.

"NASA is in the business of building unique, one-of-a-kind vehicles," Cragg told AOL News. "I thought we could help."

A drill finally broke through to the miners' underground chamber on Saturday, and rescuers began bringing the men up to the surface late Tuesday.

Cragg, 55, is part of a four-man team NASA dispatched to Chile in late August after the Chilean government asked the space agency for assistance. Its other members included two doctors, Michael Duncan and James Polk, and a psychologist, Al Holland. His colleagues were in demand from the moment they got on-site, but at first Cragg wasn't sure how he could help.

The team arrived at the mine, 500 miles north of Santiago, on Aug. 30, about a week after the miners were discovered alive. The encampment where rescue drilling crews and the miners' relatives had set up a small tent city dubbed Camp Hope was still in a state of euphoria.

"The whole atmosphere at the mine was that they were going to get these guys at some point," Cragg said. "Everybody was pulling the oars to the same beat."

While the NASA team was there, drillers had opened holes, called palomas -- the Spanish word for dove -- through which rescue workers topside sent fresh water and supplies down to the men.

"They had two holes in operation while I was there," Cragg said. "In a 24-hour period, they sent down 76 different loads. They wanted to stock them up with food in case something else happened. They sent cots down, medical supplies, vaccinations. All sorts of stuff. They were constantly in motion."

Andres Sougarret, the engineer in charge of the operation, was also working to relocate the miners' sleeping area to a more secure location deeper in the mine.

But the Chileans had not yet figured out how to actually bring the men back up to the surface. Cragg met Chilean Navy Cmdr. Renato Navarro -- also a submarine captain -- who was directing the team of Chilean naval engineers charged with creating the rescue vehicle. Though they had surveyed the site, they had not gotten far on the actual design. Cragg offered to pitch in.

"They knew what the diameter was going to be and the maximum height for the thing," he said. "But not much else. It was a pretty fluid situation."

Cragg returned to his office at NASA's Langley Research Center in Virginia and assembled about 20 NASA engineers to come up with a design. Using the same practices used in designing spacecraft, the group took three days to compile a list of 75 elements.

"The first thing you do is figure out what you want the capsule to do," he said. "For example, it has to be operated by a single person, because at the end of the day, there is going to be only one guy left to himself inside and secured."

The capsule also has to be able to withstand the friction of traveling up and down the rock walls of the mine shaft multiple times, so the NASA team gave it wheels. (And suggested an alternative: Teflon-coated sliding blocks attached to the outside of the capsule.)

"Metal scraping on rock would not last," Cragg said.

It had to have an escape hatch, in case it got stuck in the shaft. It also got a safety harness, a clock and a way to communicate with the miner inside.

NASA's medical experts weighed in, and other design elements were added: an oxygen tank, a light and a flat space in the bottom of the capsule for miners to stretch their legs.

"A parade soldier who stands at attention with his legs locked often will pass out, cutting off blood supply to the legs," Cragg explained. "As they pass out and lay on the ground in a crumpled position, blood starts flowing again, and they regain consciousness. The medical team was worried that the miners might pass out in a similar fashion, but wouldn't have the ability to fall to the ground. The thing is so tiny, it could kill a guy."

Cragg sent the list of design elements down to Chile and heard back that most of them were incorporated into the final design. Except for one: NASA gave the capsule a typical NASA-like name: the Escape Vehicle. The Chilean navy engineers, not improving on matters, christened it the Rescue Capsule.

But the name that appears to have stuck -- and Cragg isn't sure of its source -- seems much more appropriate. At Camp Hope, where eager relatives wait for the rescues to begin, the capsule is known simply as the Phoenix.