Columbia blasted off at 9:24 a.m. on June 5, 1991, with the Spacelab Life Sciences 1 module on the first totally dedicated medical research flight aboard a space shuttle. The crew was led by Bryan O'Conner, pilot Sidney Gutierrez, mission specialists James Bagian, Tammy Jernigan and Rhea Seddon and payload specialists Drew Gaffney and Millie-Hughes Fulford.