NASA Says Tile Damage Lead Theory

Feb. 3, 2003 -- Damage to Columbia's thermal tiles is the leading theory as to why the space shuttle disintegrated minutes before its scheduled landing, but NASA officials said today they are still looking for a "missing link" to help them determine the root cause of the tragedy.

Investigators are trying to determine how a piece of insulation that broke off and hit the left wing of Columbia during its Jan. 16 launch could have possibly caused the shuttle to disintegrate Saturday during its re-entry into the Earth's atmosphere, killing all seven astronauts on board.

NASA investigators have been looking at a sudden spike in temperature and a rise in wind resistance during Columbia's final minutes, both of which suggest the thermal tiles may have been damaged during the launch. Evidence indicates the temperature on Columbia's left side shot up and the craft was buffeted by greater wind resistance, forcing its automatic pilot to quickly change course before it broke up over Texas.

‘We’re Gonna Work Our Darnedest’

At a news briefing this afternoon, shuttle program manager Ron Dittemore said engineering data shows a rise of 30 degrees to 40 degrees in the left wheel well about eight minutes before the spacecraft's last radio transmission. The shuttle temperature rose the normal 15 degrees on the right side over the same period, he said. All the readings came from sensors underneath the thermal tiles, on the aluminum hull of the craft.

NASA officials determined that the piece of broken insulation was approximately 20 by 16 by 6 inches and weighed almost 3 pounds. However, Dittemore said, the temperature rise does necessarily mean there was structural damage to the shuttle. The tiles are supposed to protect the shuttle from the approximately 3,000 degrees of heat generated upon re-entry into the Earth's atmosphere, and Dittemore said the temperature rise should have been more drastic if there was structural damage.

"You can't draw the conclusion from the left main gear or the wheel that we had a breach there," Dittemore said. "If you had a breach there, it seems logical that the temperature would be higher than just 30 or 40 degrees from what we normally expect. These relatively small increases in temperature are telling us something. We're just trying to find out exactly what they're trying to tell us."

Dittemore indicated that the collection of shuttle debris is going well and "picking up steam," but investigators are still waiting to recover the missing part that will explain what cause the sudden temperature rise in Columbia's final moments.

"That missing link is out there. We just to go out there and find it," Dittemore said. "But we may never know the exact root cause and so we're gonna have to use our best judgment as to root cause. But we're gonna work our darnedest to figure that out and fix it."

Falling Insulation Wasn’t Seen as Safety Problem

Dittemore said investigators have recovered tile debris in Forth Worth, Texas, and are hoping to find more in New Mexico and Arizona — if it exists.

Still, Bill Readdy, a NASA associate administrator, told a news conference earlier today that the tiles are only one theory investigators are pursuing.

"Everyone has leaped to the conclusion that that was the cause," Readdy said. "I'm not ready to say that. … It may certainly be the leading candidate right now. We have to go through all the evidence and rule thingsout very methodically in order to arrive at the cause."

Engineers are also examining 32 seconds of computer data that came just before all communications with Columbia were lost. That data was previously ignored because it was considered flawed. However, Dittemore said, getting information from that data will take more time than initially expected. He hopes to have some useful insight within a few days.

As for the tile damage theory, NASA has said a foam insulation patch popped off the fuel tank about 80 seconds after Columbia launched. NASA officials did not realize this until the next day, when they reviewed video of the launch taken by high-speed cameras.

ABCNEWS has learned some engineers felt the flying insulation could have madea hole in the tiles or knocked some tiles off the shuttle. Readdy said it is not unusual for debris to fall off a shuttle during launch.

He said an engineering report issued on the 12th day of the shuttle's 16-day flight determined that the broken piece of insulation did cause structural damage, but concluded that there would be "no burn-through and safety-of-flight issues."

"The best and brightest engineers we have who helped design and build the system looked carefully at the analysis and information we had at the time and made a determination this was not a safety-of-flight issue," said Michael Kostelnik, NASA deputy associate administrator. "We're very aware of the anomaly that was observed. … We were in complete agreement with their assessment."

Still, Dittemore said, NASA will redo its analysis from scratch.

"We are making the assumption from the start that the external tank was theroot cause of the problem that lost Columbia," he said."That'sa drastic assumption and it's sobering."

Had the Columbia crew known of damage, though, there was probably little they could have done about it, said Sally Ride, America's first woman in space and a member of the commission that investigated the Challenger disaster. The Challenger shuttle exploded during liftoff 17 years ago.

"There really isn't a way to inspect the bottom of the shuttle and there is no way to do anything about it even if you found there was tile damage," she told ABCNEWS' Good Morning America.

A Search Expanded, a President’s Pledge

While engineers at the Johnson Space Center in Houston were analyzing billions of pieces of electronic data radioed to Earth by Columbia on Saturday morning, state and federal officials continued to search for debris of the shattered spacecraft. Tonight, investigators recovered the front of Columbia's nose cone three miles west of Hemphill, Texas, near the Louisiana border. Other officials on site say the nose cone is burrowed deep in the ground and investigators will return to the site Tuesday to dig it out.

NASA has expanded the search from central Texas to western Louisiana, and officials established a second collection site at the Naval Air Base Station Forth Worth/Joint Reserve Base in Forth Worth.

Remains of Columbia crew members have also been recovered from multiple locations and investigators want to make the fallen astronauts their priority.

"We are trying to recover these national heroes and get them back to their families as soon as possible," said Kostelnik.

President Bush met with NASA Administrator Sean O'Keefe today to get an update on the disaster, and planned to visit Houston on Tuesday to attend a memorial service for the astronauts.

The White House said it was too early to consider plans to consider rebuilding Columbia but Bush, in a speech at the National Institutes of Health in Maryland, promised that the seven astronauts did not die in vain and the space shuttle program would continue.

"The cause for which they died will continue," Bush said. "America's journey into space will continue."

ABCNEWS' Lisa Stark and Charles Gibson in Houston, Erin Hayes in Shreveport, La., and Mike Von Fremd in Nacogdoches, Texas, contributed to this report.