On February 10, in the skies above the Mojave Desert, the Boom Supersonic XB-1 test jet roared past Mach 1, tearing through the sound barrier. But this time, there was no need to take it on faith. NASA captured the moment in a striking image, making the invisible visible.
This image, a vivid display of air rippling around the aircraft, was achieved using Schlieren photography, an optical technique that reveals changes in air density. It is a dramatic visual for a future where supersonic commercial travel might return to the limelight after the retirement of the Concorde in 2003.
Seeing invisible ripples
The photograph shows the XB-1 streaking across the sky, its silhouette framed by vivid orange streaks and pale yellow exhaust trails. These streaks are shockwaves, the visual fingerprints of an aircraft pushing through the sound barrier. Capturing them required extreme precision.
Most interesting of all, perhaps, is the fact that the technology is over a century old. Schlieren photography was first developed in 1864 and relies on the principle that changes in air density — caused by pressure, temperature, or speed — bend light. However, this technique has been mostly confined to lab experiments due to special requirements like a collimated (made parallel) light beam.
The modern version of this technique is called Background Oriented Schlieren (BOS), which uses a natural textured background (in this case the desert floor) and advanced digital imaging to produce Schlieren images.
“This image makes the invisible visible,” said Blake Scholl, founder and CEO of Boom Supersonic.
A Quieter Sonic Boom
Besides the iconic image, this flight produced another milestone: there was no audible sonic boom on the ground. “We confirmed that XB-1 made no audible sonic boom,” Scholl said. That could be a game-changer.
Sonic booms have long been a barrier to overland supersonic flights. The Concorde was banned from virtually every country in the world because of the thundering noise. Only the US, Great Britain, and France allowed the Concorde to enter their airspace, and then only to cities in close proximity to the ocean — NYC, London, Paris, and Washington, DC.
Boom Supersonic managed to cancel out the loud boom by employing clever flight dynamics. At high altitudes, where the air is thinner, sound travels more slowly. When a jet breaks the sound barrier up there, it creates a loud boom. As the sonic boom moves downward, it enters denser air, where sound travels faster. This speed difference bends the sound waves upward and prevents the effects from reaching the ground.
If Boom can consistently minimize or eliminate these booms, it could convince regulators to lift restrictions, opening the door to faster coast-to-coast flights.
Supersonic revival
The XB-1’s success is a critical step toward Overture, Boom’s planned commercial airliner. Designed to carry 64 to 80 passengers at Mach 1.7, Overture aims to cut flight times in half. Already, airlines like American, United, and Japan Airlines have placed 130 orders and pre-orders for the aircraft.
Supersonic travel has always been fraught with false starts and challenges. In the 1960s, the Boeing 2707 promised a supersonic future, only to be derailed by cost overruns and regulatory hurdles. The Concorde, while iconic and with over 50,000 flights under its belt, was ultimately unsustainable, limited by its noise and high operating costs.
But Boom Supersonic is betting that new technologies will make the difference this time. The XB-1 is made almost entirely from carbon fiber composites, making it lighter and stronger than its predecessors. Its augmented reality vision system replaces the Concorde’s heavy droop nose, improving pilot visibility without adding weight. And Overture is designed to run on sustainable aviation fuel (SAF), aligning with the industry’s push toward greener travel.
“The advent of digital engineering is a huge enabler for why supersonic flight’s coming back,” Scholl told CNN. “Aerodynamics, materials, propulsion: Those are the big three areas where we’ve made huge progress versus Concorde.”
