NASA Photo ID: KSC-69PC-177
Date taken: 05/15/69
Apollo 10 command module pilot John W. Young, pauses in front of a T-38 trainer aircraft he uses to fly parabolic curves to produce brief periods of weightlessness. Astronaut Young, commander Thomas P. Stafford, and lunar module pilot Eugene A. Cernan, practiced these maneuvers in preparation for their lunar orbit flight directed by the National Aeronautics and Space Administration.
Source: NASA photo in my possession