NASA Says Tank Foam Not to Blame

NASA officials said Wednesday that they do not believe a chunk of foam insulation that struck Columbia during liftoff -- the most evident glitch in the mission -- caused damage that resulted in the space shuttle breaking apart as it reentered the atmosphere.

That incident has come under scrutiny since Columbia was destroyed Saturday. But a top NASA official, while holding a large piece of the insulation Wednesday, told reporters that investigators think the foam is too light to have caused serious damage to the craft’s thermal-tile shield. The tiles on the 173,000-pound spacecraft are one focus of the investigation.

“It does not make sense that a piece of [foam] would be the root cause of the loss of the Columbia and the crew. We don’t believe it’s the chunk of foam,” Ron Dittemore, NASA’s space shuttle program manager, said at the Johnson Space Center. “It’s got to be something else. We are focusing our attention on what we didn’t see.”

That effort has taken investigators to California, where the shuttle apparently first experienced problems, and where pieces of Columbia may have begun falling off.

In Washington, Michael Kostelnik, deputy associate administrator for the shuttle and a retired Air Force major general, said Columbia suffered some sort of “anomaly” over California. What’s more, he said, the plasma draped over the spacecraft as it raced over California changed colors at one point, suggesting that the craft may have struck an object.

NASA’s chief flight director Milt Heflin said in an interview Tuesday that NASA investigators remained unconvinced that the foam insulation was to blame for the accident, and said his engineers had begun to look for another culprit, including a collision with space junk or a space pebble known as a micrometeor.

The California Highway Patrol has received 60 calls about possible shuttle wreckage since Monday, mostly from the arid regions east and north of Los Angeles, authorities said.

However, most of the reports were dismissed as fast as they came in. In the Kern Valley, one 80-year-old man called the CHP to report that he had found wreckage from the shuttle. It turned out to be a brick, in pristine condition, officials said. Another woman called the CHP to say that she’d had a dream about the shuttle.

But some of the pieces appear to be connected to the disaster. In Joshua Tree, a man found a burned metal object in his driveway. San Bernardino County sheriff’s officials are holding the object for NASA to pick up.

Investigators are particularly interested in finding pieces that far west. The shuttle was heading east at the time of the tragedy, and it broke up over central and East Texas. Pieces found closer to the West Coast would have been the first to fall off. Their discovery could be the key to NASA’s investigation.

Kostelnik also said that some of the wreckage found in California could be from Columbia’s left wing area, the same portion of the shuttle where computers recorded a series of failures and temperature spikes in the minutes before it disintegrated.

All the California clues, Dittemore said, could be “very, very significant.”

Remains of Columbia’s seven crew members, discovered amid the wreckage in Texas and Louisiana, were flown Wednesday to a Delaware Air Force base in flag-draped caskets. An honor guard gave the remains a private reception as Deputy NASA Administrator Frederick Gregory looked on.

A military mortuary will prepare the remains for return to the families, although the only remains that had been positively identified late Wednesday were those of Ilan Ramon, the Israeli Air Force colonel who was his country’s first astronaut. That identification was made possible through dental records, officials said. Although cold, rainy weather kept many volunteer searchers indoors and slowed the recovery of wreckage in Texas and Louisiana, more than 15,000 pieces of the shuttle have been taken so far to military bases in Fort Worth and Bossier City, La.

Federal prosecutors have begun to crack down on scavengers, who have been running off with shuttle wreckage since Saturday. Two East Texas residents were charged Wednesday with theft of government property and accused of stealing a circuit board and a piece of insulating material. Authorities told the public that they would offer a grace period through Friday evening, allowing anyone else who had taken wreckage to return it without being arrested.

Some large pieces of the shuttle have been found, including the nose cone, which was towed out of a forest near Hemphill, Texas, on Wednesday. But none of the pieces has been “red tagged” as being critical to the investigation, Dittemore said.

On Jan. 16, as Columbia was headed to space, a 2 1/2-pound, 20-inch-wide piece of foam insulation fell off an external fuel tank and struck the orbiter near its left wing. NASA engineers noticed the incident while watching film of the liftoff a day later, and they conducted extensive analysis of the potential damage it might have caused, officials said.

The engineers concluded that the piece of foam might have damaged a series of tiles that are used to form armor around the space shuttle, largely to protect it during reentry to the Earth’s lower atmosphere. However, the engineers concluded, it was not enough damage, even under the worst-case scenario, to pose grave danger to the craft or the crew.

After the accident, NASA officials pledged to revisit that diagnosis and said they were considering that incident a prime suspect in their investigation. Some analysts outside NASA suggested that heavy rains may have left the foam waterlogged, coating it with heavy ice once the shuttle’s liquid hydrogen and oxygen propellants were added before liftoff.

But Dittemore said NASA is no longer considering the foam insulation a culprit in the disaster. The insulation, he said, is not sponge-like and does not sop up water, so it could not have been laden with ice, as some have suggested.

The investigation remains broad, Dittemore said, and engineers have no “favorite topic” in attempting to explain the cause.

Meanwhile, there are other avenues of information.

Computer experts are mapping the location of the recovered wreckage and, by calculating its weight and shape and how far it would have traveled once detached from the shuttle, are hoping to determine when and where the pieces fell off.

Investigators are still trying to extract information from 32 seconds of data the spacecraft is believed to have collected after Houston lost contact with the crew.

Analysts have not been able to decipher the weak signal containing that data, but Dittemore said more effort will be placed on that effort. It could be particularly important, he said, in understanding why the space shuttle recorded resistance to aerodynamics, or “drag,” on its left side -- likely from damaged tiles or other structural problems, officials said. According to data that have been retrieved, the shuttle was fighting to compensate for the drag by, among other things, firing jets that would correct its flight path. Ultimately, however, the craft could not withstand the damage.

“We were losing the battle,” Dittemore said. “Perhaps the 32 seconds will help us understand.”

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Times staff writers Matt Lait in Nacogdoches, Texas, Jessica Garrison in Los Angeles and Ricardo Alonso-Zaldivar in Washington contributed to this report.