NASA's B-52B aircraft over the Dryden Flight Research Center after the successful launch of the second X-43A hypersonic research vehicle.

The second X-43A hypersonic research vehicle, mounted under the right wing of the B-52B launch aircraft, viewed from the B-52 cockpit. The crew is working on closing out the research vehicle, preparing it for flight.

NASA's B-52B launch aircraft at sunset with the second X-43A hypersonic research vehicle attached to a modified Pegasus rocket under its right wing.

The second X-43A hypersonic research aircraft, attached to a modified Pegasus booster rocket and followed by a chase F-18, was taken to launch altitude by NASA's B-52B launch aircraft from the NASA Dryden Flight Research Center at Edwards Air Force Base, Calif., on March 27, 2004. About an hour later the Pegasus booster was released from the B-52 to accelerate the X-43A to its intended speed of Mach 7. In a combined research effort involving Dryden, Langley, and several industry partners, NASA demonstrated the value of its X-43A hypersonic research aircraft, as it became the first air-breathing, unpiloted, scramjet-powered plane to fly freely by itself. The March 27 flight, originating from NASA's Dryden Flight Research Center, began with the Agency's B-52B launch aircraft carrying the X-43A out to the test range over the Pacific Ocean off the California coast. The X-43A was boosted up to its test altitude of about 95,000 feet, where it separated from its modified Pegasus booster and flew freely under its own power. Two very significant aviation milestones occurred during this test flight: first, controlled accelerating flight at Mach 7 under scramjet power, and second, the successful stage separation at high dynamic pressure of two non-axisymmetric vehicles. To top it all off, the flight resulted in the setting of a new aeronautical speed record. The X-43A reached a speed of over Mach 7, or about 5,000 miles per hour faster than any known aircraft powered by an air-breathing engine has ever flown.

The second X-43A hypersonic research aircraft and its modified Pegasus booster rocket accelerate after launch from NASA's B-52B launch aircraft over the Pacific Ocean on March 27, 2004. The mission originated from the NASA Dryden Flight Research Center at Edwards Air Force Base, Calif. Minutes later the X-43A separated from the Pegasus booster and accelerated to its intended speed of Mach 7. In a combined research effort involving Dryden, Langley, and several industry partners, NASA demonstrated the value of its X-43A hypersonic research aircraft, as it became the first air-breathing, unpiloted, scramjet-powered plane to fly freely by itself. The March 27 flight, originating from NASA's Dryden Flight Research Center, began with the Agency's B-52B launch aircraft carrying the X-43A out to the test range over the Pacific Ocean off the California coast. The X-43A was boosted up to its test altitude of about 95,000 feet, where it separated from its modified Pegasus booster and flew freely under its own power. Two very significant aviation milestones occurred during this test flight: first, controlled accelerating flight at Mach 7 under scramjet power, and second, the successful stage separation at high dynamic pressure of two non-axisymmetric vehicles. To top it all off, the flight resulted in the setting of a new aeronautical speed record. The X-43A reached a speed of over Mach 7, or about 5,000 miles per hour faster than any known aircraft powered by an air-breathing engine has ever flown.

Jonathan Lopez works on a hypersonic Fiber Optic Sensing System at NASA’s Armstrong Flight Research Center in Edwards, California, on Feb. 13, 2025. The system measures strain and temperature, critical safety data for hypersonic vehicles that travel five time the speed of sound.

Jonathan Lopez and Allen Parker confer on the hypersonic Fiber Optic Sensor System at NASA’s Armstrong Flight Research Center in Edwards, California, on February 13, 2025. The system measures strain and temperature, critical safety data for hypersonic vehicles that travel five time the speed of sound.

Sim Ops 2002 R&D report images; SHARP (Slender Hypersonic Aerodynamic Research Probe) CTV Crew Transfer Vehicle) CGI image created by V Hawke & C Tang (Eloret Corp)

The second X-43A hypersonic research aircraft and its modified Pegasus booster rocket left the runway, carried aloft by NASA's B-52B launch aircraft from the NASA Dryden Flight Research Center at Edwards Air Force Base, Calif., on March 27, 2004. About an hour later the Pegasus booster was launched from the B-52 to accelerate the X-43A to its intended speed of Mach 7.

The second X-43A hypersonic research aircraft and its modified Pegasus booster rocket left the runway, carried aloft by NASA's B-52B launch aircraft from the NASA Dryden Flight Research Center at Edwards Air Force Base, Calif., on March 27, 2004. About an hour later the Pegasus booster was launched from the B-52 to accelerate the X-43A to its intended speed of Mach 7.

The second X-43A hypersonic research aircraft and its modified Pegasus booster rocket left the runway, carried aloft by NASA's B-52B launch aircraft from the NASA Dryden Flight Research Center at Edwards Air Force Base, Calif., on March 27, 2004. About an hour later the Pegasus booster was launched from the B-52 to accelerate the X-43A to its intended speed of Mach 7.

The second X-43A hypersonic research aircraft and its modified Pegasus booster rocket left the runway, carried aloft by NASA's B-52B launch aircraft from the NASA Dryden Flight Research Center at Edwards Air Force Base, Calif., on March 27, 2004. About an hour later the Pegasus booster was launched from the B-52 to accelerate the X-43A to its intended speed of Mach 7.

The second of three X-43A hypersonic research aircraft, shown here in its protective shipping jig, arrived at NASA's Dryden Flight Research Center, Edwards, California, on January 31, 2001. The arrival of the second X-43A from its manufacturer, MicroCraft, Inc., of Tullahoma, Tenn., followed by only a few days the mating of the first X-43A and its specially-designed adapter to the first stage of a modified Pegasus® booster rocket. The booster, built by Orbital Sciences Corp., Dulles, Va., will accelerate the 12-foot-long, unpiloted research aircraft to a predetermined altitude and speed after the X-43A/booster "stack" is air-launched from NASA's venerable NB-52 mothership. The X-43A will then separate from the rocket and fly a pre-programmed trajectory, conducting aerodynamic and propulsion experiments until it impacts into the Pacific Ocean. Three research flights are planned, two at Mach 7 and one at Mach 10 (seven and 10 times the speed of sound respectively) with the first tentatively scheduled for early summer, 2001. The X-43A is powered by a revolutionary supersonic-combustion ramjet ("scramjet") engine, and will use the underbody of the aircraft to form critical elements of the engine. The forebody shape helps compress the intake airflow, while the aft section acts as a nozzle to direct thrust. The X-43A flights will be the first actual flight tests of an aircraft powered by an air-breathing scramjet engine.

A close-up view of the front end of a Pegasus rocket booster being prepared by technicians at the Dryden Flight Research Center for flight tests with the X-43A "Hypersonic Experimental Vehicle," or "Hyper-X." The X-43A, which will be attached to the Pegasus booster and drop launched from NASA's B-52 mothership, was developed to research dual-mode ramjet/scramjet propulsion system at speeds from Mach 7 up to Mach 10 (7 to 10 times the speed of sound, which varies with temperature and altitude).

Technicians prepare a Pegasus rocket booster for flight tests with the X-43A "Hypersonic Experimental Vehicle," or "Hyper-X." The X-43A, which will be attached to the Pegasus booster and drop launched from NASA's B-52 mothership, was developed to research dual-mode ramjet/scramjet propulsion system at speeds from Mach 7 up to Mach 10 (7 to 10 times the speed of sound, which varies with temperature and altitude).

NASA's Hyper-x Program Manager, Vince Rausch talks about the upcoming launch of the X43A vehicle over the Pacific Ocean later this month from his office at NASA Langley Research Center in Hampton, VA. Hyper X is a high risk, high payoff program. The flight of the X43 A will demonstrated in flight for the first time, air breathing hypersonic propulsion technology. (Photo by Jeff Caplan)

Allen Parker, Mark Hagiwara, Paul Bean, Patrick Chan, Jonathan Lopez (seated), and Frank Pena comprise the Fiber Optic Sensing System team at NASA’s Armstrong Flight Research Center, in Edwards, California. The systems on the table measure strain and temperature, critical safety data for hypersonic vehicles that travel five time the speed of sound.

The X-43A hypersonic research aircraft and its modified Pegasus® booster rocket are nestled under the wing of NASA's NB-52B carrier aircraft during pre-flight systems testing at the Dryden Flight Research Center, Edwards, Calif. The combined systems test was one of the last major milestones in the Hyper-X research program before the first X-43A flight. The X-43A flights will be the first actual flight tests of an aircraft powered by a revolutionary supersonic-combustion ramjet ("scramjet") engine capable of operating at hypersonic speeds (above Mach 5, or five times the speed of sound). The 12-foot, unpiloted research vehicle was developed and built by MicroCraft Inc., Tullahoma, Tenn., under NASA contract. The booster was built by Orbital Sciences Corp., Dulles, Va. After being air-launched from NASA's venerable NB-52 mothership, the booster will accelerate the X-43A to test speed and altitude. The X-43A will then separate from the rocket and fly a pre-programmed trajectory, conducting aerodynamic and propulsion experiments until it descends into the Pacific Ocean. Three research flights are planned, two at Mach 7 and one at Mach 10.

As part of a combined systems test conducted by NASA Dryden Flight Research Center, NASA's NB-52B carrier aircraft rolls down a taxiway at Edwards Air Force Base with the X-43A hypersonic research aircraft and its modified Pegasus® booster rocket attached to a pylon under its right wing. The taxi test was one of the last major milestones in the Hyper-X research program before the first X-43A flight. The X-43A flights will be the first actual flight tests of an aircraft powered by a revolutionary supersonic-combustion ramjet ("scramjet") engine capable of operating at hypersonic speeds (above Mach 5, or five times the speed of sound). The 12-foot, unpiloted research vehicle was developed and built by MicroCraft Inc., Tullahoma, Tenn., under NASA contract. The booster was built by Orbital Sciences Corp., Dulles, Va. After being air-launched from NASA's venerable NB-52 mothership, the booster will accelerate the X-43A to test speed and altitude. The X-43A will then separate from the rocket and fly a pre-programmed trajectory, conducting aerodynamic and propulsion experiments until it descends into the Pacific Ocean. Three research flights are planned, two at Mach 7 and one at Mach 10.

NASA's NB-52B carrier aircraft rolls down a taxiway at Edwards Air Force Base with the X-43A hypersonic research aircraft and its modified Pegasus® booster rocket slung from a pylon under its right wing. Part of a combined systems test conducted by NASA's Dryden Flight Research Center at Edwards, the taxi test was one of the last major milestones in the Hyper-X research program before the first X-43A flight. The X-43A flights will be the first actual flight tests of an aircraft powered by a revolutionary supersonic-combustion ramjet ("scramjet") engine capable of operating at hypersonic speeds (above Mach 5, or five times the speed of sound). The 12-foot, unpiloted research vehicle was developed and built by MicroCraft Inc., Tullahoma, Tenn., under NASA contract. The booster was built by Orbital Sciences Corp., Dulles, Va.,After being air-launched from NASA's venerable NB-52 mothership, the booster will accelerate the X-43A to test speed and altitude. The X-43A will then separate from the rocket and fly a pre-programmed trajectory, conducting aerodynamic and propulsion experiments until it descends into the Pacific Ocean. Three research flights are planned, two at Mach 7 and one at Mach 10, with the first tentatively scheduled for late spring to early summer, 2001.

The first of three X-43A hypersonic research aircraft and its modified Pegasus® booster rocket recently underwent combined systems testing while mounted to NASA's NB-52B carrier aircraft at the Dryden Flight Research Center, Edwards, Calif. The combined systems test was one of the last major milestones in the Hyper-X research program before the first X-43A flight. The X-43A flights will be the first actual flight tests of an aircraft powered by a revolutionary supersonic-combustion ramjet ("scramjet") engine capable of operating at hypersonic speeds (above Mach 5, or five times the speed of sound). The 12-foot, unpiloted research vehicle was developed and built by MicroCraft Inc., Tullahoma, Tenn., under NASA contract. The booster was built by Orbital Sciences Corp., Dulles, Va.,After being air-launched from NASA's venerable NB-52 mothership, the booster will accelerate the X-43A to test speed and altitude. The X-43A will then separate from the rocket and fly a pre-programmed trajectory, conducting aerodynamic and propulsion experiments until it descends into the Pacific Ocean. Three research flights are planned, two at Mach 7 and one at Mach 10.

The NASA X-43A hypersonic research vehicle and its Pegasus booster rocket, mounted beneath the wing of their B-52 mothership, had a successful first captive-carry flight on April 28, 2001, Basically a dress rehearsal for a subsequent free flight, the captive-carry flight kept the X-43A-and-Pegasus combination attached to the B-52's wing pylon throughout the almost two-hour mission from NASA's Dryden Flight Research Center, Edwards, Calif., over the Pacific Missile Test Range, and back to Dryden.

The NASA X-43A hypersonic research vehicle and its Pegasus booster rocket, mounted beneath the wing of their B-52 mothership, had a successful first captive-carry flight on April 28, 2001, Basically a dress rehearsal for a subsequent free flight, the captive-carry flight kept the X-43A-and-Pegasus combination attached to the B-52's wing pylon throughout the almost two-hour mission from NASA's Dryden Flight Research Center, Edwards, Calif., over the Pacific Missile Test Range, and back to Dryden.

The NASA X-43A hypersonic research vehicle and its Pegasus booster rocket, mounted beneath the wing of their B-52 mothership, had a successful first captive-carry flight on April 28, 2001, Basically a dress rehearsal for a subsequent free flight, the captive-carry flight kept the X-43A-and-Pegasus combination attached to the B-52's wing pylon throughout the almost two-hour mission from NASA's Dryden Flight Research Center, Edwards, Calif., over the Pacific Missile Test Range, and back to Dryden.

The NASA X-43A hypersonic research vehicle and its Pegasus booster rocket, mounted beneath the wing of their B-52 mothership, had a successful first captive-carry flight on April 28, 2001, Basically a dress rehearsal for a subsequent free flight, the captive-carry flight kept the X-43A-and-Pegasus combination attached to the B-52's wing pylon throughout the almost two-hour mission from NASA's Dryden Flight Research Center, Edwards, Calif., over the Pacific Missile Test Range, and back to Dryden.

The Hyper III was a full-scale lifting-body remotely piloted research vehicle (RPRV) built at what was then the NASA Flight Research Center located at Edwards Air Force Base in Southern California.

The first X-43A hypersonic research aircraft and its modified Pegasus booster rocket were carried aloft by NASA's NB-52B carrier aircraft from Dryden Flight Research Center at Edwards Air Force Base, Calif., on June 2, 2001 for the first of three high-speed free flight attempts. About an hour and 15 minutes later the Pegasus booster was released from the B-52 to accelerate the X-43A to its intended speed of Mach 7. Before this could be achieved, the combined Pegasus and X-43A "stack" lost control about eight seconds after ignition of the Pegasus rocket motor. The mission was terminated and explosive charges ensured the Pegasus and X-43A fell into the Pacific Ocean in a cleared Navy range area. A NASA investigation board is being assembled to determine the cause of the incident. Work continues on two other X-43A vehicles, the first of which could fly by late 2001. Central to the X-43A program is its integration of an air-breathing "scramjet" engine that could enable a variety of high-speed aerospace craft, and promote cost-effective access to space. The 12-foot, unpiloted research vehicle was developed and built for NASA by MicroCraft Inc., Tullahoma, Tenn. The booster was built by Orbital Sciences Corp. at Chandler, Ariz.

The first X-43A hypersonic research aircraft and its modified Pegasus booster rocket were carried aloft by NASA's NB-52B carrier aircraft from Dryden Flight Research Center at Edwards Air Force Base, Calif., on June 2, 2001 for the first of three high-speed free flight attempts. About an hour and 15 minutes later the Pegasus booster was released from the B-52 to accelerate the X-43A to its intended speed of Mach 7. Before this could be achieved, the combined Pegasus and X-43A "stack" lost control about eight seconds after ignition of the Pegasus rocket motor. The mission was terminated and explosive charges ensured the Pegasus and X-43A fell into the Pacific Ocean in a cleared Navy range area. A NASA investigation board is being assembled to determine the cause of the incident. Work continues on two other X-43A vehicles, the first of which could fly by late 2001. Central to the X-43A program is its integration of an air-breathing "scramjet" engine that could enable a variety of high-speed aerospace craft, and promote cost-effective access to space. The 12-foot, unpiloted research vehicle was developed and built for NASA by MicroCraft Inc., Tullahoma, Tenn. The booster was built by Orbital Sciences Corp. at Chandler, Ariz.

The first X-43A hypersonic research aircraft and its modified Pegasus booster rocket were carried aloft by NASA's NB-52B carrier aircraft from Dryden Flight Research Center at Edwards Air Force Base, Calif., on June 2, 2001 for the first of three high-speed free flight attempts. About an hour and 15 minutes later the Pegasus booster was released from the B-52 to accelerate the X-43A to its intended speed of Mach 7. Before this could be achieved, the combined Pegasus and X-43A "stack" lost control about eight seconds after ignition of the Pegasus rocket motor. The mission was terminated and explosive charges ensured the Pegasus and X-43A fell into the Pacific Ocean in a cleared Navy range area. A NASA investigation board is being assembled to determine the cause of the incident. Work continues on two other X-43A vehicles, the first of which could fly by late 2001. Central to the X-43A program is its integration of an air-breathing "scramjet" engine that could enable a variety of high-speed aerospace craft, and promote cost-effective access to space. The 12-foot, unpiloted research vehicle was developed and built for NASA by MicroCraft Inc., Tullahoma, Tenn. The booster was built by Orbital Sciences Corp. at Chandler, Ariz.

The first X-43A hypersonic research aircraft and its modified Pegasus booster rocket were carried aloft by NASA's NB-52B carrier aircraft from Dryden Flight Research Center at Edwards Air Force Base, Calif., on June 2, 2001 for the first of three high-speed free flight attempts. About an hour and 15 minutes later the Pegasus booster was released from the B-52 to accelerate the X-43A to its intended speed of Mach 7. Before this could be achieved, the combined Pegasus and X-43A "stack" lost control about eight seconds after ignition of the Pegasus rocket motor. The mission was terminated and explosive charges ensured the Pegasus and X-43A fell into the Pacific Ocean in a cleared Navy range area. A NASA investigation board is being assembled to determine the cause of the incident. Work continues on two other X-43A vehicles, the first of which could fly by late 2001. Central to the X-43A program is its integration of an air-breathing "scramjet" engine that could enable a variety of high-speed aerospace craft, and promote cost-effective access to space. The 12-foot, unpiloted research vehicle was developed and built for NASA by MicroCraft Inc., Tullahoma, Tenn. The booster was built by Orbital Sciences Corp. at Chandler, Ariz.

The first of three X-43A hypersonic research aircraft and its modified Pegasus® booster rocket recently underwent combined systems testing while mounted to NASA's NB-52B carrier aircraft at the Dryden Flight Research Center, Edwards, California. The combined systems test was one of the last major milestones in the Hyper-X research program before the first X-43A flight. One of the major goals of the Hyper-X program is flight validation of airframe-integrated, air-breathing propulsion system, which so far have only been tested in ground facilities, such as wind tunnels. The X-43A flights will be the first actual flight tests of an aircraft powered by a revolutionary supersonic-combustion ramjet ("scramjet") engine capable of operating at hypersonic speeds above Mach 5 (five times the speed of sound). The X-43A design uses the underbody of the aircraft to form critical elements of the engine. The forebody shape helps compress the intake airflow, while the aft section acts as a nozzle to direct thrust. The 12-foot, unpiloted research vehicle was developed and built by MicroCraft Inc., Tullahoma, Tenn., under NASA contract. The booster, built by Orbital Sciences Corp., Dulles, Va., will accelerate the X-43A after the X-43A/booster "stack" is air-launched from NASA's venerable NB-52 mothership. The X-43A will separate from the rocket at a predetermined altitude and speed and fly a pre-programmed trajectory, conducting aerodynamic and propulsion experiments until it descends into the Pacific Ocean. Three research flights are planned, two at Mach 7 and one at Mach 10.

Against the midnight blue of a high-altitude sky, Orbital Sciences’ Pegasus winged rocket booster ignites after being dropped from NASA’s B-52 mothership on a July 1991 flight. A NASA chase plane for the flight is also visible above the rocket and below the B-52.

The Hyper III was a low-cost test vehicle for an advanced lifting-body shape. Like the earlier M2-F1, it was a "homebuilt" research aircraft, i.e., built at the Flight Research Center (FRC), later redesignated the Dryden Flight Research Center. It had a steel-tube frame covered with Dacron, a fiberglass nose, sheet aluminum fins, and a wing from an HP-11 sailplane. Construction was by volunteers at the FRC. Although the Hyper III was to be flown remotely in its initial tests, it was fitted with a cockpit for a pilot. On the Hyper III's only flight, it was towed aloft attached to a Navy SH-3 helicopter by a 400-foot cable. NASA research pilot Bruce Peterson flew the SH-3. After he released the Hyper III from the cable, NASA research pilot Milt Thompson flew the vehicle by radio control until the final approach when Dick Fischer took over control using a model-airplane radio-control box. The Hyper III flared, then landed and slid to a stop on Rogers Dry Lakebed.

The second X-43A hypersonic research aircraft and its modified Pegasus booster rocket accelerate after launch from NASA's B-52B launch aircraft over the Pacific Ocean on March 27, 2004. The mission originated from the NASA Dryden Flight Research Center at Edwards Air Force Base, Calif. Minutes later the X-43A separated from the Pegasus booster and accelerated to its intended speed of Mach 7.

NASA's B-52B mothership, escorted by two F-18s, makes a final flyover after its last research mission that launched the X-43A on its record Mach 9.6 flight.

Employees atop NASA Dryden's main building celebrate the return flyby of the B-52B aircraft after it launched the second X-43A aircraft on its successful flight.

The Hyper-X X-43A project team in front of NASA's B-52B launch aircraft with the Pegasus booster and X-43A vehicle attached.

The second X-43A hypersonic research aircraft and its modified Pegasus booster rocket drop away from NASA's B-52B launch aircraft over the Pacific Ocean on March 27, 2004. The mission originated from the NASA Dryden Flight Research Center at Edwards Air Force Base, Calif. Moments later the Pegasus booster ignited to accelerate the X-43A to its intended speed of Mach 7.

NASA personnel in a control room during the successful second flight of the X-43A aircraft. front row, left to right: Randy Voland, LaRC Propulsion; Craig Christy, Boeing Systems; Dave Reubush, NASA Hyper-X Deputy Program Manager; and Vince Rausch, NASA Hyper-X Program Manager. back row, left to right: Bill Talley, DCI/consultant; Pat Stoliker, DFRC Director (Acting) of Research Engineering; John Martin, LaRC G&C; and Dave Bose, AMA/Controls.

Anthony piazza, a researcher at NASA’s Armstrong Flight Research center in Edwards, California, works with high-temperature strain sensors. This test article is a bending load bar, which enables high-temperature optical strain sensor research up to 1,800 degrees Fahrenheit.

The X-37 advanced technology demonstrator flaperon unit was one of the first ever thermal and mechanical qualification tests of a carbon-carbon control surface designed for space flight. The test also featured extensive use of high-temperature fiber optic strain sensors. Peak temperatures reached 2,500 degrees Fahrenheit.

Anthony piazza, a researcher at NASA’s Armstrong Flight Research center in Edwards, California, works with high-temperature strain sensors. This test article is a bending load bar, which enables high-temperature optical strain sensor research up to 1,800 degrees Fahrenheit.

Attached to the same B-52B mothership that once launched X-15 research aircraft in the 1960s, NASA's third X-43A performed a captive carry evaluation flight from Edwards Air Force Base, California on September 27, 2004. The X-43 remained mated to the B-52 throughout this mission, intended to check its readiness for launch scheduled later in the fall.

The third X-43A hypersonic research aircraft and its modified Pegasus booster rocket left the runway, carried aloft by NASA's B-52B launch aircraft from the NASA Dryden Flight Research Center at Edwards Air Force Base, California, on November 16, 2004. About an hour later the Pegasus booster was launched from the B-52 to accelerate the X-43A to its intended speed of Mach 10.

Attached to the same B-52B mothership that once launched X-15 research aircraft in the 1960s, NASA's third X-43A performed a captive carry evaluation flight from Edwards Air Force Base, California on September 27, 2004. The X-43 remained mated to the B-52 throughout this mission, intended to check its readiness for launch scheduled later in the fall.