"I thought about the Columbia crew every single day," she told a press conference after Discovery's return to Earth.

The Discovery astronauts had a picture of the seven Columbia crew on the flight deck of their shuttle, Collins said. "Not that we really needed a picture to remember them but we wanted that."

"I thought about them throughout the whole mission, that what their experiences were, we were having the same experience ... of living in space.

"The Columbia crew believed in what they did. They believed in the space mission and I know if they are listening to me right now, they would most certainly want us to continue this mission," said the Discovery commander.

Collins said that the biggest achievment of Discovery's 14 day mission, which took supplies to the International Space Station, was "just getting the shuttle flying again.

"It has been two and a half years since Columbia. We worked very hard to do the right thing and make sure that we didn't miss anything.

"We did miss some things, you know about that. But we're learning and we're going to go back and fix those things."

"It was just absolutely successful," she declared.

Speaking about the risk of a repeat disaster from foam falling off the external tank, as it did with Columbia, astronaut Charlie Camarda said all the crew "accepted the risk."

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