Robotic camera to be sent into Utah mine

(CNN) -- Rescuers plan Monday to lower a robotic camera through a bore hole in a collapsed Utah mine to find miners who have been trapped for nearly three weeks.

Jack Kuzar of the Mine Safety and Health Administration said a seventh hole will be drilled into Crandall Canyon mine, just outside Huntington, Utah.

A sixth hole drilled into the mine was the latest to have yielded no useful information about the trapped miners' fate, said Kuzar, adding the robotic camera will be lowered through either the third or fourth hole already dug.

Robin Murphy, a mechanical engineer and director of the Center for Robot-Assisted Search and Rescue at the University of South Florida in Tampa, said the special camera is similar to one used to search in the debris of the World Trade Center following the September 11, 2001, terrorist attacks.

But she cautioned there is less than a 50 percent chance of finding any "additional information," citing the rocky and muddy conditions in the mine.

Cameras lowered into previous holes drilled into the Utah mountain turned up no signs of the miners, and tests showed oxygen levels inside the mine were too low to sustain human life.

"Frankly, it's a long shot," Murphy told reporters Sunday. "It's certainly a chance we're all willing to take."

The goal is for the robot to be lowered about 2,000 feet through one of the 8-7/8-inch sized holes onto the floor of the mine, Murphy said. Once there, it may be able to travel up to 1,000 feet, its two cameras feeding rescuers above a clearer view than they have been able to get so far.

She said her team surveyed holes three and four, but had not decided which to pursue.

"We like hole four because of its location, but it is the most difficult to get down," she said.

At eight inches in diameter, the 70-pound, waterproof robotic device will nearly fill the hole.

"If it doesn't fit, it's stuck, and there's no way to get it out," she said.

There are plenty of potential obstacles. The edge of the uncased hole is lined with raw earth, water and possibly rocks that might jam the threads of the robot or damage the camera, she said.

Upon entering the cavern, its challenging trip will not be over. The cavern ceiling is lined with chain-link fence, which could entangle the robot, though its weight should enable it to push through, she said.

If it makes it past the fence and onto the ground of the cavern, it could become mired in mud or stuck on rocks that could cause it to fall over, Murphy said.

If so, it would be difficult for the robot to correct itself, she said.

"Certainly, if we could find any sign of the miners, that would be terrific," she said. But if the venture turns up nothing useful, engineers are not sure they will be able to lift the equipment back through the hole to the surface so that it can then be lowered into another hole, Murphy said.

The device took about a week to build and another 11 hours to test on Saturday, she said.

Building a second device would take another week. The devices are made by Inuktun, based in British Columbia, Canada.

"We haven't given up hope," said Bob Murray, the president and CEO of Murray Mining, co-owner of the mine. Watch how the safety record at Murray's mines stacks up »

The six men were trapped early August 6. It is not clear whether they survived the cave-in. See a timeline of events »

Efforts to reach them were suspended 10 days later, when two rescuers and a federal mining official died and six other people were injured in a second collapse. See photos of the rescue effort »

On Saturday, Colin King, an attorney representing some of the miners' families told CNN they "are going through a living hell."

Some of the miners' relatives have been critical of Murray for not doing enough to reach the miners.

Murray told CNN earlier this week that plans were under way to establish a memorial for the missing miners at the site after the mine is closed.

"We're already discussing how we might go about to honor the trapped miners and make this a site for perpetuity," he said.

Friends and family have identified the six missing miners as Luis Hernandez, Manuel Sanchez, Kerry Allred, Carlos Payan, Brandon Phillips and Don Erickson. See the miners' profiles » E-mail to a friend

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