William Cameron "Willie" McCool (September 23, 1961 – February 1, 2003) (Cmdr, USN) was an American naval officer and aviator, test pilot, aeronautical engineer, and NASA astronaut, who was the pilot of Space Shuttle "Columbia" mission STS-107. He and the rest of the crew of STS-107 were killed when "Columbia" disintegrated during re-entry into the atmosphere. He was the youngest male member of the crew. McCool was posthumously awarded the Congressional Space Medal of Honor.