A sad day for the US space program. Our thoughts go out to the families and friends of the lost Columbia space shuttle crew: "Shuttle commander Rick D. Husband, pilot William C. McCool, payload commander Michael P. Anderson, mission specialists David M. Brown, Kalpana Chawla and Laurel Clark and Israel's first astronaut, Ilan Ramon." Here's some additional biographical information about these brave men and women, as well as some photographs.