Alan Shepard was also a Navy officer, eventually retiring at the rank of Rear Admiral.Originally posted by Owen E Oulton
"Ever wondered why NASA only takes Air Forces personnel?
Ever seen a Colonel or Naval officer in NASA's ranks?"
Many NASA astronauts are (and historically have been) Naval Aviators, including Alan Bean and James Lovell. John Glenn was a Marine Lt. Colonel. Neal Armstrong and Scott Carpenter were both former naval aviators.
Check out this site for the real skinny: http://www.jsc.nasa.gov/Bios/
Several Navy officers (who are also graduates of the Naval Postgraduate School, where I work) have been and are a part of the astronaut corps, including Apollo astronaut Captain Gene Cernan and Shuttle astronaut Captain Winston Scott. There is even a Navy medical officer who flew in space.