The Bell Aircraft Corporation X-1B, seen here on the lakebed at Edwards Air Force Base, California, was first flown for 10 flights in a three-month period by eight Edwards Air Force pilots. After being turned over to the NACA High-Speed Flight Station, it was sent to Langley Aeronautical Laboratory for instrumentation to measure structural temperatures. It was returned to the NACA High-Speed Flight Station in June 1956 for an aerodynamic heating research program at speeds near Mach 2. In January 1957 NACA test pilot Jack McKay extended the investigation to Mach 1.94. Project aeronautical engineers believed the data to be representative of heating conditions that could be expected on future Mach 2 military aircraft.