After the initial M2-F1 airtow flights, the NASA Flight Research Center used the vehicle to check out other pilots. Bruce Peterson was scheduled to take over as the M2-F1 project pilot from Milt Thompson, while Don Mallick was to be his backup. Col. (later Brig. Gen.) Charles (Chuck) Yeager, then commandant of the Air Force's Aerospace Research Pilots School, wanted to evaluate a possible lifting-body trainer for the school. This photo shows all of these distinguished pilots on or in the M2-F1, with Col. Yeager in the pilot's seat.