In this historical photo from the U.S. space agency, Jay L. King, Joseph D. Huxman and Orion D. Billeter assist NASA research pilot Milt Thompson (on the ladder) into the cockpit of the M2-F2 lifting body research aircraft at the NASA Flight Research Center (now the Dryden Flight Research Center).
The M2-F2 is attached to a wing pylon under the wing of NASA's B-52 mothership.
Each weekday, SPACE.com looks back at the history of spaceflight through photos (archive).