John Bull entered active duty with the Navy in June 1957, and received his flight training at Kingsville, Texas.
From March 1959 to November 1960, he flew F-3 Demons while assigned to VF-114 at the Naval Air Station in Mirimar, California, flying the F-3 Demon and F-4 Phanton II. Bull also served three tours on WESTPAC cruises aboard the carriers USS RANGER, USS HANCOCK, and USS KITTY-HAWK.
John S. Bull graduated from the U.S. Naval Test Pilot School in February 1964, and was named "outstanding student" of his class. He was assigned as a project test pilot in the Carrier Suitability Branch at the Naval Air Test Center at Patuxent River, Maryland, March 1964 to April 1966.
He logged more than 2,100 hours flying time; 1,800 hours in jet aircraft.
NASA selected John S. Bull as one of 19 pilot astronauts in April of 1966.
Unfortunately, Bull had to resign from astronaut duty in 1968 due to pulmonary disease. At NASA Ames Research Center, from 1973-1985, he conducted simulation and flight test research in advanced flight systems for both helicopters and fixed-wing aircraft.
From 1986 until his retirement in 1989, Bull managed NASA wide research programs in autonomous systems technology for space applications. He also provided consulting services for aerospace research and technology programs.
John Bull passed away on August 11, 2008.