Payload Commander Michael Anderson, 43, was the son of an Air Force man and grew up on military bases.
He was flying for the Air Force when NASA chose him in 1994 as one of only a handful of black astronauts. He traveled to Russia's Mir space station in 1998.
The lieutenant colonel, who lived in Spokane, Washington, was in charge of Columbia's dozens of science experiments.
"I take the risk because I think what we're doing is really important. If you look at this research flight and if you really take an opportunity to look at each experiment ... the potential yield that we have is really tremendous," he said.
He added: "For me, it's the fact that what I'm doing can have great consequences and great benefits for everyone, for mankind."