The American space agency official directing the space shuttle Columbia's return to Earth says he was not expecting any problems with the landing.
NASA shuttle re-entry director Leroy Cain says everything on the Columbia looked normal the morning of February 1. "When we came in the morning, it was as things should be on entry day," he said. "We weren't working any significant problems. Everything was setting up to be just as I would want it to be with respect to being able to de-orbit and land that day."
Mr. Cain told reporters at a news conference in Houston Friday that he knew about discussions engineers had about debris that struck the left side of the shuttle shortly after launch. But he said it didn't cross his mind again until a re-entry team member told him that four heat sensors had failed. "And because he, with his call, indicated it was on the left wing and the left elevans, that gave me pause," he said. "That was the first time I thought about that debris hit we took on ascent."
Investigators have not concluded that this debris caused the damage that doomed the shuttle. They say it's just one of many things they're looking into.
Mr. Cain said more evidence that something was wrong started building after those heat sensors failed. He said he first knew something terrible had happened when he was told of television pictures showing several streaks across the sky over Texas where there should have been only one.
He said at that point he and the ground control crew relied on their disaster training for what to do next, and they did all they could to save the crew. Mr. Cain said he stands by their actions that morning. "I never had any doubts, and I still don't doubt what we did or didn't do," he said. "The kind of problem that we suffered on this day, there isn't anything the flight control team could have done differently, or should have done differently."
The Columbia Accident Investigation Board reported Wednesday that something probably punched a hole in the shuttle's skin. That hole in the skin would have let in superheated gas that surrounds the shuttle as it re-enters the Earth's atmosphere.