- The Washington Times - Sunday, February 2, 2003

CAPE CANAVERAL, Fla., Feb. 2 (UPI) — Temperatures on the fuselage above shuttle Columbia's left wing spiked sharply minutes before the space ship broke apart over east Texas, killing its seven-member crew and stunning a space agency obsessed with safety since the Challenger accident 17 years ago.

Engineers have begun the painstaking work of piecing together the puzzle of what caused Columbia's demise on Saturday as it soared toward a landing strip in Florida after 16 days in orbit.

Shuttle program manager Ron Dittemore said Sunday his team had picked out two "significant" temperature spikes relayed by radio links from sensors aboard the shuttle shortly before the ship disappeared from ground tracking stations and communications with the crew ceased.

Both anomalies occurred on the shuttle's left side. The first was relayed at 8:53 a.m. ET as Columbia flew over California 23 minutes before the planned touchdown. A sensor in the shuttle's left wheel well showed a 20- to 30-degree temperature rise over five minutes.

The data followed NASA's first indication of a problem when four other sensors located in the wheel well stopped relaying data.

A minute later, temperatures in the shuttle's left fuselage, located below the wing, climbed 60 degrees in five minutes, compared with the more normal 15-degree increase registered in the right fuselage.

Additional problems were noted at 8:58 a.m., with Columbia over New Mexico. The shuttle's automated flight control system compensated for excessive drag on the shuttle's left side as the orbiter was going through its first roll to burn off speed in preparation for landing. The drag could have been caused by rough or missing tiles, which are critical to protecting the shuttle from the 3,000-degree Fahrenheit temperatures experienced during atmospheric re-entry.

Also at this time, sensors monitoring pressure and temperature in the shuttle's main landing left tire stopped working.

Less than two minutes later, all data and communications with the shuttle were lost and observers in Texas saw contrails in the sky, marking Columbia's demise. NASA has spoken with and taken written reports from shuttle-watchers in California who reported seeing "debris" shedding from the orbiter minutes earlier, said Dittemore.

Though still early in the investigation, the evidence could show Columbia lost a critical section or sections of its thermal protection system, including possibly the door to its landing gear or the panel covering where its external fuel tank had been attached prior to reaching orbit.

"We certainly know that the wheel well area is one of our sensitive areas thermally," said Dittemore. "We've analyzed that area intensively in the past and the loss of any one single tile, we believe, would not be a cause for loss of a vehicle.

"What's interesting to us," Dittemore added, "is that as we are starting to look at the trail of (the failed sensor) wiring as it goes through the (left) fuselage and out to the (left wing) elevon, it has a common point as it goes adjacent to the wheel well. That's all we know today and I don't want to speculate any more. I want to be careful that I don't jump to conclusions because if I do I'll miss something else that may be very important," he said.

Adding to possible evidence of thermal protection system damage is a video clip taken during Columbia's launch on Jan. 16 showing what appears to be a piece of foam from the external fuel tank falling off and striking the left wing.

NASA engineers studied the video, analyzed the possible impacts of the debris hit and dismissed the issue as not a concern for flight but something that would be analyzed in greater detail following Columbia's return to Earth. It was the second incident of external fuel tank insulation hitting the shuttle at liftoff during the past three shuttle flights.

"It's not clear to me yet that we have evidence that the debris was the root cause," said Dittemore, though he added that thermal problems were a more likely cause of the shuttle's breakup than structural issues. "It's too early to speculate on what all that means."

NASA hopes to glean more evidence from an additional 32 seconds of flight data as well as from the debris that is being collected from Texas and Louisiana. Remains of the seven astronauts also have been found, said astronaut Bob Cabana, director of flight crew operations.

"We're honoring our fellow crewmates and we're taking care of them," he said.

A memorial service for Rick Husband, Willie McCool, Kalpana Chawla, Michael Anderson, David Brown, Laurel Clark and Ilan Ramon is scheduled for Tuesday in Houston. President George W. Bush is expected to attend.

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