Investigators for the U.S. Space Agency, NASA, are running tests on selected pieces of debris recovered from the space shuttle Columbia. Officials continue to focus on the orbiter's left wing as they try to pinpoint what caused the shuttle to disintegrate minutes before its scheduled landing February 1.
For weeks, NASA crews have been cataloguing and arranging more than 30,000 pieces of debris in a massive hangar at the Kennedy Space Center at Cape Canaveral, Florida.
Spokesman Bruce Buckingham says initial examinations of the debris confirm widely held theories that point to the left wing as the culprit in the disaster.
"There is a solid belief that, whatever happened, it happened on the left wing," he said. "And it is becoming more and more obvious by looking at the damage to the tiles and even damage to the landing gear on the left wing as opposed to the damage [that can be seen] on the right wing."
Mr. Buckingham says telltale markings have been detected on debris from the left wing. These markings indicate the orbiter's left side was subjected to higher temperatures and greater stress than the right side. Mr. Buckingham says tests are being conducted to determine just how hot thermal tiles became during the orbiter's final minutes, but he cautions against expectations for quick answers to the overall mystery.
"There are some very interesting marks on them. Now, whether they are marks caused as a result of the accident or part of [contributing to] the accident, we are not sure yet. These marks have [indications of] extremely high heat; some of the tiles are fractured into multiple pieces. It is going to require a long, drawn out analysis to determine exactly what happened," he said.
Investigators say concrete answers to the shuttle disaster remain elusive. But they theorize that damage to Columbia's left wing allowed superheated gasses to stream in as the shuttle hurtled through the upper atmosphere at more than 18 times the speed of sound. Investigators note that a piece of insulating foam peeled off the external fuel tank during lift-off and struck the orbiter's left wing, possibly damaging the heat-resistant tiles.