Boom Supersonic's next-generation XB-1 passenger plane 1 step away from breaking the sound barrier
Boom Supersonic's XB-1 demonstrator craft could become the first commercial jet to break the sound barrier since Concorde after acing its 11th test and reaching 0.95 Mach at low altitudes.
Get the world’s most fascinating discoveries delivered straight to your inbox.
You are now subscribed
Your newsletter sign-up was successful
Want to add more newsletters?
Delivered Daily
Daily Newsletter
Sign up for the latest discoveries, groundbreaking research and fascinating breakthroughs that impact you and the wider world direct to your inbox.
Once a week
Life's Little Mysteries
Feed your curiosity with an exclusive mystery every week, solved with science and delivered direct to your inbox before it's seen anywhere else.
Once a week
How It Works
Sign up to our free science & technology newsletter for your weekly fix of fascinating articles, quick quizzes, amazing images, and more
Delivered daily
Space.com Newsletter
Breaking space news, the latest updates on rocket launches, skywatching events and more!
Once a month
Watch This Space
Sign up to our monthly entertainment newsletter to keep up with all our coverage of the latest sci-fi and space movies, tv shows, games and books.
Once a week
Night Sky This Week
Discover this week's must-see night sky events, moon phases, and stunning astrophotos. Sign up for our skywatching newsletter and explore the universe with us!
Join the club
Get full access to premium articles, exclusive features and a growing list of member rewards.
The unofficial successor to Concorde is one step closer to reality after Boom Supersonic marked the 11th successful test flight of its XB-1 supersonic demonstrator aircraft.
On Jan. 10, the XB-1 completed a sustained flight at 728 mph (1,172 km/h) — equivalent to Mach 0.95, which is just shy of the speed of sound.
The test was conducted at a height of 29,481 feet (8,986 meters); while the aircraft flew at this speed in its 10th test, that test was at a much higher altitude and therefore a lower air pressure.
By flying so fast, so low in the latest test, the XB-1 achieved a record 383 knots equivalent airspeed — indicative of incredibly high dynamic air pressure. The aircraft will never experience such intense conditions again even when it finally breaks the sound barrier, as its in-service flights will take place at much higher altitudes where the air is thinner, company representatives said in a statement.
Putting the aircraft under this strain at transonic speed, just below the speed of sound, demonstrates the robust quality of its airframe and proves it will remain controllable at higher speeds.
The company had previously stated that it would aim to hit and exceed Mach 1 speeds in early 2025. Depending on the need for a 12th test flight, the firm is on track to meet this target.
Related: Passenger plane with entirely new 'blended wing' shape aims to hit the skies by 2030
Get the world’s most fascinating discoveries delivered straight to your inbox.
Boom Supersonic began test flights with the XB-1 in March 2024 . Subsequent flights have probed its stability with and without its digital handling system and stress-tested the frame of the aircraft using a device that simulates the potentially disruptive energy caused by airflow at high velocity, while also pushing it to ever-faster maximum speeds.
"The second half of our test campaign is all about expanding XB-1's envelope incrementally in altitude, air speed, and Mach number until we inevitably make that sonic boom," Nick Sheryka, chief flight test engineer for the XB-1 at Boom Supersonic, said in a promotional video.
"But why not just go supersonic on the next flight? It's important to remember that XB-1 is not a drone; there's a human pilot inside that cockpit. With an autonomous aircraft, there's no risk to human life. This is how new space rocket technology is iterated on so quickly, but you and your family are not going to step onto a drone airliner anytime soon," he added.
Much like how SpaceX's early rocket launches laid the groundwork for its larger Starship project, the XB-1 is intended as a testing platform that Boom Supersonic can use to help develop Boom Overture, a supersonic passenger plane the company hopes will start service in the 2030s.
If successfully launched, the Boom Overture could carry 64 to 80 passengers on transatlantic journeys that will take just 3 hours and 30 minutes between London and Newark.
Rory Bathgate is a freelance writer for Live Science and Features and Multimedia Editor at ITPro, overseeing all in-depth content and case studies. Outside of his work for ITPro, Rory is keenly interested in how the tech world intersects with our fight against climate change. This encompasses a focus on the energy transition, particularly renewable energy generation and grid storage as well as advances in electric vehicles and the rapid growth of the electrification market. In his free time, Rory enjoys photography, video editing and science fiction. He joined ITPro in 2022 as a graduate, after completing an MA (Hons) in Eighteenth-Century Studies at King’s College London. You can contact Rory at rory.bathgate@futurenet.com.

