Boeing NB-52A Stratofortress 52-003, The High and Mighty One, with North American Aviation X-15A-2 56-6671 mounted to the pylon under its right wing. The external propellant tanks have been brightly painted to aid tracking after they are jettisoned. (U.S. Air Force)
Boeing NB-52A with X-15A-2 (S/N 56-6671). This X-15 is on display at the National Museum of the United States Air force. (U.S. Air Force photo)