In a stunning series of images, NASA has revealed the moment an experimental supersonic aircraft broke the sound barrier without producing a sonic boom audible at ground level.
The images were obtained using specialized photographic methods during flight tests with the XB-1, a demonstrator aircraft produced by Boom Supersonic, the company behind the development of the world’s fastest airliner, Overture.
The collaboration between NASA and Boom Supersonic offers a rare view of supersonic flight. Visual confirmation of shock waves and other data provide new insights into how aeronautical engineers can reduce the impact of sonic booms, ushering in a new era of supersonic travel without noise.
Supersonic Flight without Audible Sonic Booms
The XB-1’s second supersonic flight occurred over the Mojave Desert on February 10, 2025. NASA scientists on-site employed a unique variety of photography to capture the air disturbance produced by the aircraft as it passed overhead.
The special technique employed by the NASA team, known as Schlieren photography, dates back to the 1860s and is used today to visualize the flow of air around objects. This technique is particularly useful in the study of supersonic motion.
Subsequent analysis by Boom’s team of technicians confirmed that no audible sonic boom reached the ground during the February flight test, marking a crucial milestone in helping to determine the feasibility of quiet supersonic travel.
Capturing the Shock Waves of Supersonic Flight
Currently, the XB-1 is the first independently developed civil supersonic jet and became the first privately built aircraft to exceed the speed of sound in January 2025.
Although NASA provided the specialized imaging equipment to document the XB-1’s flight tests in February, the American space agency has its own separate Quiet Supersonic Technology (QueSST) program, which involves NASA’s experimental X-59 aircraft.
NASA’s use of ground-based telescopes with special filters allowed Boom’s researchers to detect the shock waves surrounding XB-1 as it accelerated beyond Mach 1.
During the test, Boom’s Chief Test Pilot, Tristan “Geppetto” Brandenburg, was required to position the company’s aircraft at a precisely calculated waypoint that placed the XB-1 directly in front of the sun. The maneuver was no small feat and required split-second timing and advanced avionics guidance.
“This image makes the invisible visible—the first American-made civil supersonic jet breaking the sound barrier,” said Blake Scholl, Founder and CEO of Boom Supersonic, in a statement released this week.
“Thanks to Geppetto’s exceptional flying and our partnership with NASA, we were able to capture this iconic image. We also confirmed that XB-1 made no audible sonic boom, which paves the way for coast-to-coast flights up to 50% faster,” Scholl added.
Proof of Supersonic Flight at the ‘Mach Cutoff’
During the experimental flight last month, NASA and Boom produced advanced modeling of atmospheric conditions prior to the XB-1’s takeoff. This allowed them to better gauge the occurrence of what is known as Mach cutoff, a phenomenon that occurs when a sonic boom refracts in the atmosphere, preventing it from reaching the ground.
During testing, NASA used specially placed microphones and sound pressure recording devices to collect data along the XB-1’s flight path. As Boom’s analysts had hoped, data revealed that the XB-1’s supersonic flights could be achieved without producing a sonic boom that reached the ground, which aligns with NASA’s ongoing research into commercial supersonic travel.
From XB-1 to Overture: The Future of Supersonic Travel
Since the test flights last month, Boom has announced its intent to begin integrating its findings into the development of Overture, the company’s next-generation supersonic airliner.
Featuring the company’s Boomless Cruise technology, which enables quiet supersonic travel up to Mach 1.3, Overture is expected to reduce travel from coast to coast in the United States by as much as 90 minutes. If all goes according to plan, Overture will be the fastest and most efficient airliner in production, which the company says will be optimized for speed, safety, and sustainability.
The supersonic airliner is expected to operate on up to 100% sustainable aviation fuel (SAF), and the company says it has already secured 130 orders and pre-orders from airlines, including American Airlines, United Airlines, and Japan Airlines. Boom is also in talks with defense contractor Northrop Grumman regarding potential defense applications for their new supersonic technology.
The End of XB-1’s Flight Test Program
As for the XB-1, the aircraft, which first flew in March 2024, as production efforts move toward the development of Overture, the original prototype will now return to Denver, Colorado, where Boom will scale its learnings to advance the development of its highly anticipated supersonic airliner.
As full-scale production of Overture nears, Boom recently announced the completion of its new super factory facility in Greensboro, North Carolina. There, the company says that up to 66 of its aircraft will be able to be produced annually.
With the successful completion of XB-1’s test flights and NASA’s validation of Boomless Cruise, the future of commercial supersonic travel is looking to be much quieter than its past iterations. This is thanks to the successful combination of speed and efficiency with revolutionary low-volume supersonic flight technologies.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. He can be reached by email at micah@thedebrief.org. Follow his work at micahhanks.com and on X: @MicahHanks.