Investigators yesterday turned west to Arizona and California in their search for debris that might link the space shuttle’s destruction to the breakaway chunk of insulation that smashed Columbia’s wing tiles 81 seconds after launch.
“We’ve had reports that there are pieces on the ground in California and in Arizona,” said retired Gen. Michael Kostelnik, deputy associate administrator for shuttle and space station activities at the National Aeronautics and Space Administration.
He said credible reports and e-mail correspondence indicate the items include material from thermal tiles or a wing. NASA specialists were dispatched yesterday to check the reports, he said. Each tile is numbered to pinpoint where it fits on the shuttle.
“Debris early in the flight path would be critical because that material would obviously be near the start of the events” that preceded the shuttle’s disintegration over Texas, Gen. Kostelnik said.
Also yesterday, an engineering professor said NASA was warned nine years ago that the space shuttle could fail catastrophically if debris hit the vulnerable underside of its wings during liftoff.
After receiving the warning, NASA made changes in equipment and flight rules to reduce the risk of debris breaking loose, said Paul Fischbeck of Carnegie Mellon University, who conducted the analysis.
The underside of the left wing is where NASA is focusing its probe of Saturday’s disaster.
A circuit board and landing gear from the space shuttle, the kind of evidence officials said would be important enough to bear the “red tag,” were found with pieces of the fuselage in eastern Texas near the Louisiana border, not far from where the nose cone was discovered.
Gen. Kostelnik, speaking for NASA on a day when other officials attended a memorial service for the seven astronauts killed, rejected reporters’ implications that space could be explored without risk.
Asked why the agency had no backup plan for potential emergencies such as damage to protective thermal tiles, Gen. Kostelnik said NASA emphasized safety and installed redundant systems for critical ones that might fail.
“But there are not a lot of margins on some of these activities. … Given the risk and the moving parts, it’s been a remarkable record of safety considering the challenge we face,” he said.
“The further away we get from the globe, the more difficult these challenges are going to be,” Gen. Kostelnik said, referring to yesterday’s recommitment to space by President Bush and NASA Administrator Sean O’Keefe.
During re-entry Saturday, the left wing of the 22-year-old shuttle orbiter overheated near a landing-gear door where the ceramic tiles sustained a supersonic hit on Jan. 16.
On takeoff, a brick-hard block of insulation peeled away from the supercold fuel tank it had protected, hit the shuttle beneath its wing near the left landing gear door, then glanced off and dissipated into a white cloud.
The 2.67-pound piece of hardened foam about the size of a carry-on suitcase was probably the largest foreign object to strike protective ceramic tiles in the program’s 113 launches, Gen. Kostelnik said.
He said the incident surprised NASA, which learned of it from films reviewed a day after the launch. Even if technicians had recognized a danger, NASA officials said, there would be no way to fix it or to rescue the crew.
Gen. Kostelnik said he was confident that Columbia’s astronauts were told of discussions about the potential for danger from the insulation hitting the tiles.
“I would be surprised if they were not … but I don’t know that personally,” he said.
Gen. Kostelnik said the search for critical debris would be vigorous but that it would be impossible to retrieve everything beyond “the big pieces.”
He said NASA learned of new images of Columbia’s final moments, including some taken by the crew of a military Apache helicopter as the shuttle passed over it and possibly high-resolution Air Force re-entry photographs that could show if tiles were damaged or missing.
The wisdom of the NASA decision that this time there had been “no burn-through and no safety-of-flight issue” was likely to draw sharp attention from the independent board investigating the accident.
Board members and staff specialists tried yesterday to get the feel of the heavy debris field around Nacogdoches, Texas.
“I know that we won’t go out and solve the mystery this morning,” said retired Navy Adm. Harold W. Gehman Jr., chairman of the independent commission selected by NASA officials, who led the group journey to examine some of the 12,000 or more pieces of wreckage from the 89-ton shuttle.
Hundreds of searchers made several discoveries yesterday in eastern Texas and Louisiana, including more human remains, a seat from the shuttle and cylindrical tanks spewing an unknown gas.
In Vernon Parish, La., a woman out walking found fabric bearing a blue Star of David on a silver background, Sheriff Sam Craft said. The object is presumably a patch from the suit of Israeli astronaut Col. Ilan Ramon.
Later yesterday, authorities in Texas said a 6- to 7-foot section of what they believed to be part of a shuttle wing was found in a pond east of Nacogdoches.
NASA specialists said temperature spikes measured before Saturday’s explosion indicated “a thermal event” caused the accident but said rises in the fuselage near the left wing of up to 60 degrees in five minutes were too small in themselves to explain the catastrophic failure 16 minutes before Columbia’s scheduled landing in Florida.
Loose or rough tiles were blamed for forcing down the wing to some 57 degrees from horizontal, while jets on the right side fired for 1.5 seconds to compensate for the yaw.
NASA engineering teams used computer projections of trajectories in New Mexico, Arizona and California to determine the line along which thermal tiles or wing pieces most likely would be found if they fell before the breakup.
The Arizona Republic reported yesterday that police and federal officials wearing biohazard suits retrieved from four Phoenix locations charred material that could be from Columbia. Debris also was found in Mesa and Yavapai counties, the newspaper said.