EDWARDS AIR FORCE BASE, Calif -- The Martin Marietta X-24A prototype aircraft made its last flight on this day. After 28 flights, USAF engineers redesigned and heavily modified the blunt-shaped X‑24A and renamed it the X-24B. Tne "B" model possessed a longer fuselage, increased width, and sharply changed platform. The X-24B proved to have three times the maneuverability of the original design.
Both, the United States Air Force and the National Aeronautics and Space Administration jointly developed the aircraft within an program named PILOT. This program ran from 1963 through 1975. The program's primary purpose involved testing of lifting body concepts, experimenting with the concept of unpowered reentry and landing. The Space Shuttle later utilized these same concepts.
During testing, the X-24 would detach from a modified B-52 Stratofortress at high altitudes before igniting its rocket engine and after expending its fuel load, the pilot would glide the X-24 to an unpowered landing.