William H. Dana, American engineer, pilot, and astronaut (d. 2014)

William Harvey "Bill" Dana (November 3, 1930 – May 6, 2014) was an American aeronautical engineer, U.S. Air Force pilot, NASA test pilot, and astronaut. He was one of twelve pilots who flew the North American X-15, an experimental spaceplane jointly operated by the Air Force and NASA. He was also selected for participation in the X-20 Dyna-Soar program.

On two separate flights, Dana flew the X-15 to an altitude above 50 miles, thereby qualifying as an astronaut according to the United States definition of the boundary of space; however, neither flight exceeded the Kármán line, the internationally accepted boundary of 100 kilometers (62 miles).