A 1953 photo of some of the research aircraft at the NACA High-Speed Flight Research Station (now known as the the Dryden Flight Research Center). The photo shows the X-3 (center) and, clockwise from left: X-1A (Air Force serial number 48-1384), the third D-558-1 (NACA tail number 142), XF-92A, X-5, D-558-2, and X-4.