- The Washington Times - Sunday, February 9, 2003

HOUSTON (AP) One week after the Space Shuttle Columbia broke apart as it streaked over Texas, just minutes from home, NASA still has more questions than answers.
Searchers have recovered remains of all seven astronauts and more than 12,000 shards of metal, wires and debris that rained down across two states. But the findings so far have yielded few clues.
The most significant discovery has been a 2-foot section of shuttle wing, including the carbon-covered leading edge designed to protect Columbia's insulating tiles as the spacecraft heats to 3,000 degrees re-entering the atmosphere.
If that section came from the troubled left wing, where temperatures surged in the shuttle's final moments and sensors failed in rapid sequence, it could provide hard evidence of what went wrong.
Investigators hadn't yet determined to which wing the fragment belonged, but they should know "in relatively short order," NASA Administrator Sean O'Keefe said yesterday after a memorial service at Louisiana's Barksdale Air Force Base, where pieces of the shuttle are stored.
In the shuttle's final eight minutes on the morning of Feb. 1, temperatures surged in the left landing gear compartment, and the brake lines began overheating one by one. Sensors began showing overheating across other areas of the left wing and adjoining fuselage. Then Mission Control lost all contact, and Columbia broke apart.
Investigators are considering every possible scenario, from the impact of a large chunk of hard insulating foam that hit the shuttle seconds after liftoff on Jan. 16, to a deadly bulls-eye's strike by a piece of space junk, to a lightning-like electrical phenomenon in the upper atmosphere.
The seemingly innocuous piece of foam once NASA's focus, then all but discarded is back at the heart of the mystery.
The 2-pound chunk of insulation, measuring 20 inches by 16 inches by 6 inches, broke off Columbia's external fuel tank 81 seconds after liftoff and smacked into the left wing, where the sensors later failed during the shuttle's return.
Engineers studied the impact while Columbia was in orbit and concluded it posed no safety threat. Now they're redoing their analyses, in excruciating detail, to see if they might have missed anything.
It's also possible that something more than the foam chunk such as ice or maybe hardware came off the fuel tank or booster rockets and ricocheted into Columbia.
Imagery experts are poring over a high-resolution photo taken by an Air Force telescope a minute or two before Columbia broke apart.
Some have suggested the leading edge of the left wing looks as if it could be damaged, and the photo shows a gray streak that could be a fiery plume trailing the wing.
Shuttle program manager Ron Dittemore acknowledges confusion, misinformation and "even some second-guessing on all of our parts" in the past week.
NASA is no longer even certain exactly what time temperatures started to rise and sensors started to malfunction during Columbia's final eight minutes of flight.
The sequence of sensor measurements and failures is puzzling, particularly one reading in a part of the mid-fuselage not connected to any of the wire bundles linked to the other sensors that were going haywire.
"Whether that's important or not, we don't know," Mr. Dittemore said.

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