The NASA Neil A. Armstrong Flight Research Center (AFRC) is an aeronautical research center operated by NASA. Its primary campus is located inside Edwards Air Force Base in California and is considered NASA's premier site for aeronautical research. AFRC operates some of the most advanced aircraft in the world and is known for many aviation firsts, including supporting the first crewed airplane to exceed the speed of sound in level flight, highest speed by a crewed, powered aircraft, the first pure digital fly-by-wire aircraft, and many others. AFRC operates a second site next to Air Force Plant 42 in Palmdale, California, known as Building 703, once the former Rockwell International/North American Aviation production facility. There, AFRC houses and operates several of NASA's Science Mission Directorate aircraft including SOFIA, a DC-8 Flying Laboratory, a Gulfstream C-20A UAVSAR and ER-2 High Altitude Platform. As of 2023, Bradley Flick is the center's director.

The North American X-15 is a hypersonic rocket-powered aircraft operated by the United States Air Force and the National Aeronautics and Space Administration (NASA) as part of the X-plane series of experimental aircraft. The X-15 set speed and altitude records in the 1960s, crossing the edge of outer space and returning with valuable data used in aircraft and spacecraft design. The X-15's highest speed, 4,520 miles per hour, was achieved on 3 October 1967, when William J. Knight flew at Mach 6.7 at an altitude of 102,100 feet (31,120 m), or 19.34 miles. This set the official world record for the highest speed ever recorded by a crewed, powered aircraft, which remains unbroken.