Shuttle Wing Piece Could Be Key Clue

NASA said Friday it has found what might be its most critical clue in the quest to explain the destruction of Columbia -- a section of a wing that could help investigators understand a string of failures detected before the shuttle disintegrated over Texas one week ago.

NASA has linked more than 12 temperature spikes and sensor failures in the left wing of the shuttle to a system of wire bundles that coursed through the shuttle’s left wing and delivered electricity and data, said Ron Dittemore, the agency’s space shuttle program manager.

Also, the space agency said Friday it is reviewing photographs taken of Columbia’s last minutes by personnel at Kirtland Air Force Base on the outskirts of Albuquerque. The black-and-white photos are grainy and show only the Columbia’s silhouette, but they appear to show a trail coming from the left wing of the shuttle.

Though NASA officials were still debating the value of the photographs late Friday, they could be the only images showing the drag -- resistance to aerodynamics -- that prompted the shuttle’s autopilot to take corrective action in the minutes before the craft broke apart.

The investigation remains focused on the shuttle’s left wing, where the problem may have started or where it manifested itself, investigators said. Michael Kostelnik, deputy associate administrator for the shuttle and a retired Air Force major general, has said the shuttle suffered an “anomaly” over California, and said Friday that the evidence surrounding the left wing is “of vital interest.”

Still, a week after the Columbia disaster, NASA investigators are far from being able to draw conclusions.

They are stymied by evidence of the drag that plagued the shuttle nearly 10 minutes before it broke apart, because there were no indications from the crew or its computers that the craft was experiencing any problems. They cannot determine whether the temperature spikes and other abnormalities along the left wing represent a cause of the accident or a symptom of a larger hardware failure.

They have received 350 reports of debris landing in California, Arizona and New Mexico, but investigators have had time to look into only 16 of those accounts, and have not confirmed a single one.

Each lead, so far, has only raised more questions. For example, video taken in the Bay Area purportedly shows the shuttle being struck by lightning or some other electric event. Investigators are unsure of that video’s legitimacy, and have summoned weather experts to Johnson Space Center in Houston to discuss whether there were atmospheric electric events 200,000 feet high in an otherwise clear sky -- and whether that could have brought down the shuttle.

The investigation, involving thousands of scientists and engineers, is markedly different from the one that followed the space shuttle program’s other catastrophe. In 1986, when the Challenger exploded 73 seconds after lifting off in Florida, NASA officials were fairly certain within hours the accident would be attributed to faulty O-rings designed to seal the shuttle’s rockets. They were right.

Dittemore said NASA is not willing to take the risk of drawing any conclusions -- not yet, anyway. He has worked to calm workers and investigators frustrated by dead-ends. Friday, he traveled to east New Orleans. There, contract workers at NASA’s Michoud Assembly Facility apply the shuttle’s foam insulation, the same material that peeled off during liftoff and struck the craft, leading to suspicions that it damaged heat-resistant tiles and ultimately destroyed Columbia. The workers there “feel as though they have the weight of the world on their shoulders,” Dittemore said.

“It’s been a frustrating week,” he said. “The emotion has run high. The disappointment cannot be overstated. You want to draw conclusions as quick as you can. But you can’t do that. You go down that merry path of making a rush to judgment and you will be fooled.”

Even the investigators’ excitement over the wing portion found near Fort Worth was tempered.

That wreckage, which is 26 inches long, includes 18 inches of wing material, investigators said. It is covered by several of the ceramic tiles that form a shield around the bulk of the shuttle, protecting it from the violent ride from space into the Earth’s atmosphere. Those tiles, many believe, failed somehow during Columbia’s descent, possibly allowing excessive heat to breach the shuttle.

Investigators have confirmed the wreckage is from the “leading edge” of a wing, which is the portion of the wing that strikes the atmosphere most directly and is subjected to the highest temperatures, sometimes 3,000 degrees. It was found on the western edge of the shuttle’s known debris field, suggesting that it came loose from the eastbound craft early in the accident.

But, as of Friday night, investigators had not been able to determine whether the wreckage of the wing stems from the left side of the craft, which would be very significant.

“We have a tremendous amount of work to do,” Dittemore said. “We have a long way to go.”

The wing debris was en route to the former Carswell Air Force base near Fort Worth, now a Naval air station reserve base.

Dittemore released the most detailed explanation yet of temperature spikes and sensor failures leading up to the accident. All the recordings were made in the eight minutes before mission control in Houston lost communication with the craft.

The data show that the failed equipment is clustered on or near the left wing. And, though investigators initially could not find any common problem between the recordings, Dittemore said they appear to be part of a system of wire bundles supplying electricity and data to that portion of the craft.

Dittemore also denied a report in The Times in which several analysts said NASA could be forced to consider, as a last resort, using one of its remaining three space shuttles for parts to ensure an abbreviated launch schedule.

The remaining shuttles, he said, will fly “as long as the government and this nation desires that we keep those vehicles flying.”

The search for thousands of pieces of the shuttle -- which was 16 minutes from landing in Florida when it disintegrated, killing seven crew members -- continued Friday.

After being identified, packaged and tagged at two staging areas, one at the former Air Force base near Fort Worth, the other near Shreveport, La., the items will be taken to Kennedy Space Center in Florida. There, Dittemore said, investigators will attempt to reconstruct the shuttle.

One team is looking for several large pieces of the shuttle that radar indicated had fallen near the Texas-Louisiana state line. Another is looking for a device NASA uses to encrypt communications between mission control and astronauts in space.

In Nacogdoches, Texas, a grace period for residents accused of looting shuttle debris came and went. A total of 19 people dropped off debris at the sheriff’s office, but authorities said they suspected 75 others were still in possession of government property.

Nacogdoches County Sheriff Thomas Kerss said those names will be forwarded to the FBI, though federal prosecutors say they are more interested in recovering all of the shuttle debris and protecting the integrity of the investigation than pursuing criminal charges.

Authorities in that region of East Texas will soon fan out to flea markets in an attempt to find people selling debris. Two people have already been indicted for stealing wreckage, and the allegations of continued looting come on the heels of several offers to sell Columbia debris on the Internet auction site EBay.

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Hot spots on the left wing

NASA officials have pieced together a seven-minute sequence in which the shuttle Columbia’s left wing area emitted a staccato series of sensor alerts and shutdowns before all contact with mission control was lost.

7:52:20 a.m.: Sensor in left main gear brake line records a temperature rise of 2 degrees/minute.

7:52:39 a.m.: Another sensor in same area records a rise of 6 degrees/minute.

7:52:48 a.m.: A third sensor, in the wheel well, shows a rise of 5 degrees/minute.

7:52:59 -7:53:36: Five sensors relating to left wing elevon shut down.

7:54:13 a.m.: Sensor in left main gear brake line records a rise of 6 degrees/minute.

7:54:22: Sensor on the fuselage above the left wing records a rise of 6 degrees/minute, the only problem not directly corrected to the wing.

7:54:27: Left main gear strut sensor shows a rise of 7 degrees/minute.

7:54:36: Another sensor in left main gear area shows a 4 degree/

minute rise.

7:55:23: Sensor from switch valve in wheel well shows a rise of 5 degrees/minute.

7:55:35: Wheel temperature sensor in left landing gear shuts down.

7:56:20: Skin temperature sensors in upper and lower wing shut down.

7:57:54: Left-rear break switch valve sensor records a 14 degree/minute rise.

7:58:33: Main landing gear sensors for left tire pressure shut down.

7:58:35: Wheel temperature sensor for left landing gear also shuts down.

7:58:39: Two more left tire pressure sensors in main landing gear shut down.

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Source: NASA - Researched by Times graphics reporter Joel Greenberg

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Times staff writers Eric Malnic and Lianne Hart contributed to this report.