NASA Administrator O'Keefe Visits Stennis Space Center

As investigators search for the cause of the Columbia disaster, NASA's chief came to Mississippi and Louisiana Thursday to show his support to workers who built and tested vital parts of the shuttle.

Sean O'Keefe talked to Stennis Space Center employees about their role in future space flights, and the continuing investigation into the Columbia disaster.

"It is just mystifying as to how this happened. We don't know. We can't figure it out yet, but we are going to. We're going to figure out what the cause of that was... and we're going to get back to flying safely," O'Keefe said.

Stennis employees said that kind of encouraging talk gives them confidence for the future.

"I'm encouraged, I really am. And I really think most of us are. It's encouraging to get word from the top," Stennis Worker Robert Bruce said.

"I know in the challenger incident it was two years, and a good part of a third, before we were actually able to fly again. I feel confident that we will be flying a lot sooner than that," Aerospace Engineer Wayne North said.

O'Keefe said there still can be some good that comes from a tragic disaster like losing the Space Shuttle Columbia.

"Witnessing it, it ought to give us an awful lot more resolve that we really are all about, what we are engaged in, is something terribly important. It's not just space flight, it's everything we're engaged in here at NASA," O'Keefe said.

Earlier in the day, O'Keefe was at the Michoud Assembly Facility in New Orleans East. That's where the shuttle's external fuel tanks are produced.

Also Thursday, NASA announced the first set of mission needs for a new orbital space plane. The newly designed craft will replace shuttles on space station missions by 2012 and respond quickly to space station emergencies. It will be safer, cheaper and require less preparation time than the shuttle.