Guion S. Bluford, Jr.

Astronaut Guion Bluford (right) and Aviation Safety Officer Charles F. Hayes get a unique perspective during a zero gravity training flight aboard a KC-135 aircraft on 2 March 1979. Also known as the "vomit comet," the KC-135 flies a special parabolic pattern repeatedly to afford a series of 30-seconds-of-weightlessness sessions. (NASA photo)