David Mathieson Walker was an Eagle Scout and a 1962 graduate of Eustis High School. After graduating from the United States Naval Academy, he became a naval aviator and a highly decorated veteran of the Vietnam War. In 1978, he was selected by NASA as an astronaut for the Space Shuttle program. By the time of his retirement in 1996, Captain Walker was a veteran of four Space Shuttle missions, three of which he commanded.