Discovery's astronauts had misgivings about the risky spacewalk mission to the shuttle's fragile belly but agreed to try the repair because it seemed relatively easy to do, crewmembers said on Tuesday. On Wednesday, Steve Robinson will make space history when he ventures out to Discovery's smooth underside to try to remove two loose fiber strips sticking out from between the crucial heat-resistant tiles. "Like most kinds of repairs, it's conceptually very simple, but it has to be done very, very carefully," Robinson said during a news conference from space on NASA's first shuttle flight since the 2003 Columbia disaster. The...