On January 28, aerospace startup Boom Supersonic achieved a significant feat, breaking the sound barrier in a manned civilian aircraft, the XB-1. The flight marked the first time a privately funded company has managed to engineer, manufacture and fly a supersonic aircraft. Simply put, this achievement is a really big deal. Breaking the sound barrier is an act defined both by its rarity and complexity. But what does it actually mean, and why is it so noteworthy?
What does it mean to break the sound barrier?
Breaking the sound barrier occurs when an aircraft exceeds the speed of sound. But accomplishing this means more than just hitting the gas really, really hard. The planes capable of breaking the sound barrier need to be constructed with specific materials that can withstand the pressure put on them by traveling at supersonic speed. Those specific materials need also to be able to withstand the extreme temperature produced by the friction created at high speed. The aircraft needs to be meticulously engineered to handle the changes in stability that occur when the air flows over the plane’s wings and fuselage.
A supersonic aircraft isn’t just one that can handle flying at an extreme speed: it’s a true feat of engineering across the board.
How fast is supersonic speed?
Supersonic speed is reached when an aircraft exceeds the speed of sound, which is 1,125 feet/second or in layman’s terms, about 760 miles per hour. The speed required to do this is commonly referred to as Mach 1. When a big metal bird approaches this speed, the molecules in the air surrounding it are quickly and violently compressed, resulting in a shockwave.
What is a sonic boom, and what does it sound like?
When the shockwave reaches the ground and comes within earshot of humans, it produces a sonic boom, which sounds like a loud thunderclap.
I know what you’re thinking: what does a sonic boom sound like if you’re in a plane that’s just broken the sound barrier? This will be disappointing to hear, but it doesn’t sound like anything. The sonic boom isn’t the sound of the plane reaching supersonic speed, but the sound of the shockwave created through that process as it reaches the ground. By the time that boom is audible Earthside, the plane responsible for its creation is several thousand feet past it.
While it’s clearly feasible from an engineering standpoint to travel at Mach 1, it’s been a long time since breaking the sound barrier occurred with any kind of regularity. There’s a reason for that: it’s oftentimes illegal.
Why is it illegal to break the sound barrier?
While breaking the sound barrier over the high seas is fine, creating a sonic boom over land is generally illegal—as it is in the US—or heavily restricted, as it is elsewhere. The noise and reverberations from it can cause panic and property damage and are, in general, disruptive and scary. The US Federal Aviation Administration prohibits civilian aircraft from flying at any Mach number, save for special exceptions.
But the XB-1 flew over the Mojave desert, though – clearly over land. That’s because the FAA provided permission in August 2024 for the company to launch test flights up to 20 times over the course of the year. January’s successful flight was their 12th attempt. This type of permission is extremely rare for civilian aircraft and signals a pretty significant shift in the way the FAA and the industry as a whole approach the return to supersonic speed for passenger air travel.
More than FAA permission, Boom Supersonic is challenging conventional norms when it comes to the literal “boom” from a broken sound barrier.
“Yesterday’s supersonic flight made no audible sonic boom,” wrote Boom Supersonic CEO Blake School on X the day after XB-1’s flight. “I wanted to call it, ‘The boom heard ‘round the world,’ but it wasn’t heard anywhere. Not all booms are created equal, and at certain speeds and conditions, the boom doesn’t reach the ground.”
Going forward, Boom Supersonic might have a convincing case to make for reversing the FAA’s law on breaking the sound barrier, as their aircraft can do so without disturbance to the public.
Why is breaking the sound barrier such a big deal?
Creating a supersonic aircraft that can safely reach Mach 1 and make that big sonic boom requires advanced engineering to manage the massive aerodynamic forces involved. Simply put, it’s a really difficult thing to pull off. However, the XB-1 was the first privately developed civil aircraft to break the sound barrier. Plenty of aircraft preceded it in this feat, starting with Chuck Yeager’s historic flight in 1947, but most have been military-engineered or otherwise government-funded, so the investment made and manpower dedicated to those projects was significant. Boom Supersonic, however, is a 150-person, privately funded startup.
Without endless funding or limitless staff, the company has made up the difference by investing in and relying on digital engineering technologies like computational fluid dynamics and virtual twins to ideate, develop, optimize and simulate its aircraft. By creating virtual mockups, Boom Supersonic’s team is able to test the limits of modern aerospace advancements despite its small staff and comparatively small budget. This shows the power of innovation and private investment in pushing boundaries and achieving significant milestones in aviation.
What does this mean for the future of supersonic travel?
The XB-1 serves as more than just a technological milestone. It’s the proving ground for Boom’s larger ambition: reintroducing supersonic flights for passenger travel. The aircraft the company is developing for this purpose, Overture, is creating quite a bit of buzz in the industry. Overture, which Boom Supersonic has been developing using Dassault Systèmes technologies including CATIA, ENOVIA and SIMULIA since its conception, has already been pre-ordered by more than 130 major airlines. This kind of buzz isn’t just good news for Boom Supersonic – it marks widespread interest in ushering in a new era of high-speed travel.
Overture, though, wouldn’t be the first sound barrier-breaking passenger jet. It’s preceded by the Concorde, which you might remember from the news or from the movie “The Parent Trap,” depending on your age and film interests. The Concorde, which was funded by the British and French governments, flew transatlantic flights for 27 years before being officially retired in 2003.
Boom Supersonic has its work cut out for itself. The Concorde eventually failed for a number of reasons, and Overture needs to address those issues to become genuinely commercially viable. The Concorde was loud, limited in scope and highly unsustainable. The project’s development cost nearly $20 billion, a staggering sum in the 1960s and 70s. As breaking the sound barrier is illegal over land, the planes were only allowed to fly on routes across the Atlantic Ocean. They were also highly environmentally destructive. Per passenger, their CO2 emissions were higher than any other aircraft, and the carbon dioxide emitted at high altitudes – the Concorde flew at heights of 60,000 feet, far above what today’s planes cruise at – contributed to depletions in the ozone layer. On top of that, the Concorde was also extremely expensive to fly on, with tickets running as much as $10,000 for a flight between London or Paris and New York.
Overture is setting up to change that. Because Boom Supersonic is developing the aircraft using virtual modeling tools, it’s possible that the costs associated with manufacturing and maintaining the planes will be lower and eventually, the cost for consumers will make them a viable travel option. Beyond that, Overture will also run on sustainable aviation fuel, signaling an early commitment to larger industry goals to reduce the environmental footprint associated with air travel. It’ll also travel at Mach 1.7, significantly faster than the speed needed for that big ol’ sonic boom, a pretty flashy selling point. Given the commitment by some of the world’s largest airlines to purchase these aircraft, it’s very well possible that Overture will, in fact, be the future of travel for the masses.
Redefining global connectivity for a new era of air travel
XB-1 and Overture represent a reimagining of what air travel can be—a faster, more connected world made possible without sacrificing efficiency or sustainability. The return to supersonic flight holds the potential to revolutionize the aviation industry, cutting travel times in half and redefining human mobility on a global scale.
The road – ahem, skies – ahead is ambitious but promising. With the XB-1 as its foundation, Boom Supersonic’s vision of making sound barrier-breaking travel accessible to all appears to be not just a far-off dream but an attainable reality. Powered by modern engineering, sustainable practices, bold ambition and most importantly, knowledge of past failures, Boom Supersonic just might be poised to reshape the future of flight, one super-fast plane at a time.
Shoshana is a Senior Communications Manager on the Corporate Publishing team here at Dassault Systèmes. With experience in journalism, marketing, and PR, her work has been published around the world and across the internet.