William C. McCool, 41, a commander in the U.S. Navy, was a former test pilot. He served as pilot for STS-107. He received a bachelor of science in applied science from the U.S. Naval Academy in 1983, a master of science in computer science from the University of Maryland in 1985, and a master of science in aeronautical engineering from the U.S. Naval Postgraduate School in 1992. McCool, as a member of the Blue Team, worked with the following experiments: European Space Agency (ESA) Advanced Respiratory Monitoring System (ARMS); ESA Biopack (eight experiments); Mediterranean Israeli Dust Experiment (MEIDEX); and the Physiology and Biochemistry Team (PhAB4) suite of experiments, which included Calcium Kinetics, Latent Virus Shedding, Protein Turnover and Renal Stone Risk. He was also responsible for maneuvering Columbia as part of several experiments mounted in the shuttle's payload bay.
Selected by NASA in April 1996, McCool was making his first spaceflight.