Michael John Smith, 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, when it broke up 73 seconds into the flight, and at an altitude of 48,000 feet, killing all 7 crew members. Smith's voice was the last one heard on the Challenger voice recorder. He was a Master of Science who held a degree in Aeronautical Engineering.