The X-24B transformed the “teardrop” shape into a “flying iron,” paving the way for space vehicles capable of atmospheric reentry and gliding landing.
In summary
The X-24B represents a major advance in the history of experimental aircraft and space vehicles. With its unique architecture—a double-delta wing fuselage with a flat belly and rounded back—it proved that lift could be generated by the body alone, without traditional wings. During 36 flights between 1973 and 1975, including 24 powered flights, it demonstrated remarkable capabilities: reaching Mach 1.75 (~ 1,873 km/h) and an altitude of 22.6 km, then gliding to land precisely like an airplane. These successes profoundly influenced the design of reusable space vehicles, notably the future orbiter of the Shuttle program. The X-24B thus contributed to the realization of the concept of safe “atmospheric reentry + gliding landing.”
The lifting body concept applied to the X-24B
The X-24B is part of the “lifting body” concept—aircraft whose fuselage generates the lift necessary for flight without the use of traditional wings. This concept reduces aerodynamic drag and the surface area exposed to friction, which is essential for vehicles that must withstand high thermal stresses (atmospheric reentry, high speed).
The program originally focused on the X-24A, launched in 1969: a bulbous, teardrop-shaped aircraft designed to test the feasibility of atmospheric re-entry followed by a gliding landing.
After 28 flights (some at Mach 1.6, or approximately 1,040 mph, up to an altitude of 21.8 km), engineers decided that an aerodynamic redesign was necessary to improve stability and gliding performance. This led to the creation of the X-24B.
The “flying flatiron” shape and its technical implications
The change in shape between the X-24A and X-24B was radical: the bulbous structure was replaced by a flat belly, rounded back, double-delta wing, and pointed nose. This configuration—described as a “flying flatiron”—was proposed following studies by the Air Force Flight Dynamics Laboratory aimed at maximizing the lift-to-drag ratio.
This design brought several concrete benefits: first, the increase in the lower wing area improved glide and stability. The longer fuselage and sharp nose reduced drag at high speeds. These attributes made the X-24B more maneuverable, more efficient at gliding long distances, and reliable for precise landing.
Performance and concept validation
The X-24B flew 36 times between 1973 and 1975, including 12 glide flights (without engines) and 24 powered flights. The typical procedure was to launch from an aircraft carrier (a modified B-52) at approximately 13.7 km (45,000 feet), ignite the rocket engine to reach high altitude and speed, then shut down the engine to begin reentry and glide to landing.
During testing, the aircraft reached a maximum speed of 1,164 mph (approximately Mach 1.75, or ~1,873 km/h) and an altitude of 74,100 feet (~22.6 km). At the end of the program, the X-24B successfully completed precision glide landings on a hard runway at Edwards Air Force Base—a crucial demonstration that a wingless vehicle could return from space and land like an airplane.
Impact on fighter jet and spacecraft technology
Although the X-24B was never a fighter jet, its results had significant implications for aeronautics and space travel. By validating the concept of a flying wing—a fuselage that provides lift—the program showed that a vehicle could combine hypersonic performance, controlled atmospheric reentry, and gliding landing without an engine. This approach directly fueled thinking about reusable vehicles, notably the Shuttle program’s orbiter.
In addition, the use of a double-delta wing, a flat belly, and a tapered nose are all technical features that inspire the modern profiles of supersonic and hypersonic aircraft, where the management of lift, drag, high-speed stability, and atmospheric reentry is crucial. The X-24B therefore played a fundamental role as a “test bed” for the evolution of advanced aerodynamics.
Limitations, lessons learned, and legacy
The flying wing concept has certain advantages—reduced drag, better thermal management, and gliding without an engine. But it also presents challenges: at low speeds, the absence of conventional wings makes the aircraft less stable, and maneuverability can be tricky without traditional lifting surfaces.
The X-24B proved the feasibility of precise, controlled gliding flight. Nevertheless, the program never reached operational status: it was a demonstrator, not a commercial or combat aircraft. Its use was limited to testing, but it had a real impact on the design of space vehicles. Several decades later, the influence of its results can still be seen in reusable spacecraft projects.
The X-24B on display today at the museum
The only remaining example of the X-24B is on display at the Air Force Museum at Wright-Patterson Air Force Base, Ohio. This aircraft bears witness to the audacity of the engineers of the 1970s, who were prepared to challenge aeronautical conventions in order to test radical designs.
A bridge between experimentation and the future
The X-24B remains a technical milestone: it embodied the idea that a wingless vehicle could take to the air, withstand the stresses of atmospheric reentry, and land on a runway like an airplane. This paradigm made it possible to imagine and develop reusable spacecraft with profiles optimized for reentry.
Its technical legacy lives on: the aerodynamic concepts it validated—lift from the fuselage, double-delta wing, tapered nose, flat belly—still inform thinking today about supersonic or hypersonic aircraft, and even future orbital transport vehicles with gliding reentry.
sources
Martin Marietta X-24 (Wikipedia article, English)
NASA – X-24B fact sheet (NASA website)
National Museum of the U.S. Air Force – X-24B fact sheet
National Interest – article “The X-24B Is A True Aviation Legend for a Reason”
MilitaryFactory.com – Martin X-24B lifting-body description
Wikipedia encyclopedia – article “Lifting body”
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