Investigation Turns to Shuttle Heat Tiles

NASA investigators said Monday they now suspect Columbia’s heat-resistant tiles might have begun falling off early in its descent, leading them to question whether they failed to recognize the damage caused when a piece of foam insulation struck the craft’s left wing during liftoff. As the hunt for pieces of the space shuttle accelerated, officials said the investigation could hinge on finding even a single tile that might have fallen off as far west as California and nestled in a remote prairie, desert or farm, said Ron Dittemore, NASA’s space shuttle program manager. If tiles did detach, he said, “Where are they?”

Investigators have been poring over data showing a startling string of temperature spikes recorded by onboard sensors in the minutes before Columbia tore apart over East Texas on Saturday morning.

Many of those temperature readings were near the left wing of the shuttle, the same area struck by a 2 1/2-pound piece of foam insulation during its Jan. 16 liftoff. That incident, which might have damaged a strip of thermal tiles 32 inches long and 7 inches wide, remains a focus of the investigation, NASA said.

Dittemore said the increases in temperature were not a problem in and of themselves. As recorded by onboard gauges, most temperatures rose just 40 degrees before the shuttle broke apart -- relatively insignificant considering temperatures outside were as high as 3,000 degrees. But they could have been an early indication that something was going wrong with the heat shield.

“There is some other event that we don’t have yet,” Dittemore said. “It’s a mystery. That missing link is out there. It’s like looking for a needle in a haystack.... We may never know the exact root cause.”

At least one of the shuttle’s 20,000 thermal tiles was discovered Monday near Fort Worth, farther west than officials thought any debris had landed. Investigators opened a second staging area to collect debris at the former Carswell Air Force Base in Fort Worth, now a naval air station and reserve base. The bulk of the debris is being taken to Barksdale Air Force Base outside Shreveport, La.

The debris field is now believed to be at least 250 miles long, from east-central Texas to western Louisiana. The sheer size of the debris field has fueled debate over whether NASA can, or should, try to reconstruct the shuttle piece by piece.

. Such reconstruction has been done only on airplanes. After the 1996 crash of TWA Flight 800, aviation experts retrieved about 90% of the wreckage from the waters off Long Island, then put it back together. Investigators were able to eliminate the possibility that a missile or other object had brought the plane down by finding bulging areas near a fuel tank, identified as the root of the crash.

That investigation was a “breakthrough” in aviation science, said Peter Goelz, former managing director of the National Transportation Safety Board. Several NASA officials, including Michael Kostelnik, deputy associate administrator for the shuttle and a retired Air Force major general, said Monday that they would like to duplicate the feat.

Among the hundreds of volunteers, law enforcement officers and National Guardsmen conducting the search for debris, though, that goal remains elusive.

On the eastern edge of Texas, Wayne Holt, San Augustine County judge and emergency management coordinator, said members of search-and-recovery teams have returned with blood streaming down their arms because of the scratches they received rooting through thick briars. Others had begun searching on horseback for remains and debris, only to find that they couldn’t see through the brush that far off the ground.

Even with those restrictions, San Augustine County alone has found more than 2,000 debris sites, many of them with five or six chunks of material. Debris has been found in dozens of Texas counties, Holt said, including a piece the size of a pickup truck, believed to be most of the cockpit, and the nose of the shuttle, discovered Monday night in a field just west of the Louisiana line in Hemphill, Texas.

Scavengers were making off with debris from the spacecraft. And illustrating the difficulty of recording the exact landing position of each piece of wreckage, one piece was found being carried around by a golden retriever in central Shreveport.

“They’ll never get it back together,” Holt said.

Looking at the Liftoff

The investigation also continues to focus on the 20- by 16- by 6-inch piece of foam insulation that struck the shuttle left wing 80 seconds after it lifted off Jan. 16 in Florida.

NASA laid out for the first time Monday the efforts its engineers took to study that incident. Several teams, examining film of the incident and similar episodes on previous flights, concluded that any structural damage to the shuttle’s tiles was inconsequential and would not cause “a catastrophic loss,” Dittemore said. The shuttle mission managers received those final reports on Jan. 24 and 27.

But Dittemore acknowledged that many of the sensors that failed on the shuttle’s reentry were in the same area of the craft that was struck by the foam. And NASA administrators have ordered engineers to take another look at the incident.

Among other things, Dittemore said, they will investigate whether the piece of foam insulation was coated in ice when it struck the wing, which would have increased its mass and the force of the impact greatly. It remained unclear whether engineers investigated that possibility initially, NASA officials said late Monday.

NASA officials acknowledged that their own analysis, conducted while the shuttle was in space, showed that the piece of foam insulation could have caused two types of damage to the space shuttle. Computers estimated that the foam chunk might have ripped off a single protective tile near a landing gear door. Or a strip of tiles 32 inches long and 7 inches wide could have been damaged, the computers concluded.

Still, engineers determined that the damage was not sufficient to destroy the shuttle.

“We want to know if we made erroneous decisions,” Dittemore said. “We are redoing the complete analysis. We want to know if we made any mistakes.”

Officials have acknowledged that even if they knew the damage from the foam insulation had the potential for disaster, there was little they or the astronauts could do once the shuttle lifted off.

The craft was not equipped with a robotic arm that could investigate or fix broken tiles, for example, and the astronauts could not reach the shuttle’s underbelly to fix any damage manually, officials say.

Drastic Option Available

Dittemore said that had NASA concluded that damage to the tiles would have prevented reentry, mission leaders could have put the shuttle on a course that would have destroyed the craft but given the crew a chance to survive if it ejected.

But NASA would have taken that drastic action only if it had “absolute, sure knowledge” that the craft was so damaged that it could not otherwise survive reentry, Dittemore added.

NASA officials bristled at suggestions that they could have done more to protect the astronauts. “We can second-guess all day long,” Dittemore said. “Be cautious of that line of thinking.”

At Barksdale Air Force Base, officials said honor guards have begun escorting in the astronauts’ remains, discovered scattered in East Texas prairies and thickets.

Underscoring the difficult task of identifying the bodies and the body parts, officials declined to drape the caskets with American flags in case they contained remains of Ilan Ramon, the Israeli astronaut onboard Columbia when it tore apart Saturday morning.

Memorial Service Today

The families of the seven dead astronauts, meanwhile, steeled themselves for a memorial service scheduled for this afternoon at Johnson Space Center, the NASA complex on the southern tip of Houston where the Columbia crew trained for several years before its ill-fated mission. President Bush and First Lady Laura Bush are expected to arrive in Houston today to take part in the ceremony.

Acknowledging calls to revamp NASA’s mission, possibly by curbing the use of manned spacecraft, the families released a joint statement Monday calling instead for renewed vigor in the “bold exploration of space.”

“Once the root cause of this tragedy is found and corrected, the legacy of Columbia must carry on -- for the benefit of our children and yours,” the families said.

Underscoring that sentiment, President Bush said in a speech at the National Institutes of Health in Bethesda, Md., that “while we grieve the loss of these astronauts, the cause in which they died will continue.

“American’s journey into space will go on,” Bush said.

Earlier, Bush met for 45 minutes in the Oval Office with Sean O’Keefe, NASA’s administrator, in a conference that the White House presented as an effort by Bush to boost morale of the agency employees as well as a meeting to learn the latest on the investigation.

“You make us proud,” Bush said, according to White House Press Secretary Ari Fleischer.

Capitol Hill Hearings

Congressional hearings on the Columbia disaster are expected to begin next week in the House and Senate, and will focus on “the immediate cause, and the remedies that can be made as soon as possible, so that the program can continue,” said Sen. John McCain (R-Ariz.).

By coincidence, federal officials released NASA’s proposed budget for the next fiscal year Monday, amid questions of whether budget restraints had any role in compromising safety. Under the proposal, NASA would receive $15.5 billion in 2004, a slight increase that includes nearly $4 billion for the space shuttle program.

Senate Majority Leader Bill Frist, a Tennessee Republican, said on the floor of the Senate Monday that while it is premature to blame the accident on a tight budget, that will be among the issues examined by congressional investigators.

Also Monday, the father of Ramon, Israel’s first astronaut, said he was grateful to the American people, Israel and NASA for their support.

“They really are doing their best,” Leizer Wolferman told a crowd during a memorial service in Houston.

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Staff writers James Gerstenzang and Edwin Chen in Washington and Matt Lait in Shreveport, La., contributed to this report.

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(BEGIN TEXT OF INFOBOX)

Key events of the mission

Jan. 16: Columbia launches from Cape Canaveral, Fla.

Jan. 17: First film review shows insulation break from external fuel tank.

Jan. 20 Engineers assess potential damage from insulation.

Jan. 21 Engineers report incident to debris assessment team.

Jan. 22 Meetings to analyze potential damage. Team determines two scenarios: Falling insulation knocked a 6-by-6-inch tile from main landing gear door or a wider portion of tile closer to the left wing’s edge was damaged or knocked off.

Jan. 23-24: Final engineering reviews.

Jan. 27: Engineering and mission management teams concur that debris poses no threat to the safety of the shuttle or crew.

Feb. 1: Shuttle breaks apart on reentry; all seven on board are killed.

Source: NASA