Michael John Smith (April 30, 1945 – January 28, 1986), (Capt USN) was an American engineer and astronaut. He served as the pilot of the Space Shuttle Challenger when it was destroyed during the STS-51-L mission, breaking up 73 seconds into the flight, and at an altitude of 48,000 feet (14.6 km), killing all seven crew members. Smith's voice was the last one heard on the Challenger voice recorder.