NASA asks farmers for help with debris

SPACE CENTER, Houston -- As the days become weeks since Columbia's disintegration over Texas, fewer and fewer pieces of space shuttle wreckage are turning up, even though the calls keep coming in.

On Monday, NASA asked farmers and ranchers out West to be on the lookout during spring plowing for anything that might have fallen from the sky on Feb. 1.

"It's kind of a mixed thing. There's a tremendous amount of information available already, even though not everything directly points to a particular thing. There are a lot of circumstantial things," said NASA's Steve Nesbitt, who is serving as the spokesman for the accident investigation board.

He added that "there's a continuing belief and feeling that things are going to continue to develop" and that more debris may be found.

Now that the investigation board is back in Houston following a series of road trips to other NASA centers, the members can settle into a routine and start digging into all of the information being accumulated, Nesbitt said.

Many phone calls

Nesbitt took a phone call over the weekend from a Louisiana woman who has an odd chunk of plastic in her flower bed and wants NASA to check it out. He also heard from a California retiree who wanted to tell the board his theory for the shuttle disaster.

"Everybody wants to contribute. They all want to help and it's great. The board certainly wants to listen," Nesbitt said. But he noted: "It will take a while to get back to the people," given the disproportionate ratio of callers to those following up on all the calls.

Nine of the 10 board members met Monday at their new headquarters in an office building just a mile from Johnson Space Center and planned to hold a weekly news conference, their second, Tuesday. The 10th member, newly selected Sheila Widnall, a former secretary of the Air Force, will join the group later in the week.

So far, the investigation board has publicly put forth just one hypothesis: that a breach in the left wing likely allowed superheated gases to penetrate the spacecraft.

Paul Fischbeck, a Carnegie Mellon University engineering professor, said that hypothesis makes his own analysis "more and more likely." In a 1990 study and follow-up research, Fischbeck concluded that a space shuttle could fail catastrophically if debris hit the vulnerable underside of its wings during liftoff.

Barely a minute into Columbia's flight on Jan. 16, a chunk of insulating foam broke off the external fuel tank and slammed into the bottom of the left wing.

The head of the independent investigation board, retired Navy Adm. Harold Gehman Jr., has stressed repeatedly that he is not ruling anything out.