🛫 It's been over 20 years since Concorde retired in 2003. The dream of supersonic passenger travel—grounded by "thunderous" sonic booms— is being revived by Japanese technology. JAXA's "quiet supersonic aircraft" uses world-leading technology to reduce sonic boom noise by more than half. With flight tests scheduled for 2028, the full picture is now emerging.
JAXA's Vision for a "Quiet Supersonic Aircraft"
In January 2026, JAXA (Japan Aerospace Exploration Agency) unveiled the latest concept images of its next-generation supersonic passenger aircraft. The design is based on conceptual work funded by NASA and others, enhanced with JAXA's proprietary "Robust Low-Boom Design Technology." The aircraft is envisioned as a small supersonic airliner carrying approximately 50 passengers.
The concept images reveal a distinctively elongated, needle-like nose and wings with complex curved surfaces. This isn't mere aesthetics—it's a scientifically calculated shape designed to control airflow and transform the ground-level sound from a thunderous "boom" into a muffled "thump."
Why Concorde Failed
When thinking of supersonic passenger aircraft, many recall Concorde, the Anglo-French marvel that operated from 1976 to 2003. Flying at Mach 2, Concorde could cross the Atlantic from Paris or London to New York in just 3.5 hours.
However, Concorde faced a fatal flaw. The "sonic boom"—shockwaves generated during supersonic flight—created explosive sounds on the ground, leading to bans on supersonic flight over land. Combined with poor fuel efficiency, Concorde's routes were limited to oceanic crossings like the transatlantic route, and it ultimately retired without achieving commercial success.
Understanding Sonic Booms
When an aircraft exceeds the speed of sound, shockwaves form around various parts of the airframe. As these waves propagate through the atmosphere, they merge and create a sudden pressure variation known as an "N-wave" at ground level. To human ears, this sounds like a nearby lightning strike or a large firework explosion.
Crucially, sonic booms occur not just when breaking the sound barrier, but continuously throughout supersonic flight. A strip-shaped area called a "boom carpet" forms beneath the flight path, where the shockwave constantly reaches the ground.
Japan's Unique "Robust Low-Boom Design Technology"
JAXA began supersonic aircraft research in 1997 and has achieved several major milestones since then.
In 2005, JAXA conducted flight tests of the small supersonic experimental aircraft "NEXST-1" in Australia, demonstrating a 13% reduction in aerodynamic drag compared to Concorde. In 2015, the "D-SEND (Drop test for Simplified Evaluation of Non-symmetrically Distributed sonic boom)" project conducted flight tests in Sweden, becoming the first in the world to demonstrate technology capable of reducing sonic boom intensity to half that of Concorde.
The current "Re-BooT (Robust Low-Boom Supersonic Transport Design Technology Demonstration)" project advances this technology further. While previous approaches focused on reducing sonic booms directly beneath the flight path, Robust Low-Boom Design Technology achieves noise reduction across the entire boom carpet—including off-track positions and during acceleration climbs. This technology is patented domestically and internationally, representing a significant advantage for JAXA.
Flight Tests Planned for 2028
The Re-BooT project plans to conduct flight tests around 2028. The demonstrator will be an unmanned aircraft approximately 10 meters in length. While it won't carry an actual engine, its shape will allow evaluation of sonic boom waveforms equivalent to those of a passenger aircraft.
During testing, the demonstrator will be carried by a piloted "mother aircraft" to an altitude of approximately 13 kilometers before separation. The demonstrator will then accelerate to supersonic speeds through gravity, flying under autonomous computer control while ground-based measurement systems record the sonic boom data.
JAXA plans to present its findings to ICAO (International Civil Aviation Organization) to contribute to the development of international noise standards for supersonic aircraft. Standards are expected to be determined at the 2031 ICAO Assembly, which would create an environment where companies can begin developing commercial aircraft.
The Global Supersonic Race
Japan isn't alone in pursuing supersonic passenger travel. In the United States, NASA and Lockheed Martin's jointly developed "X-59" completed its first flight in October 2025. Though using a different approach than JAXA, the X-59 aims for the same goal of demonstrating "quiet" sonic technology.
Additionally, American startup Boom Supersonic is developing "Overture," a supersonic airliner designed for oceanic routes only, targeting commercial operations in the 2030s.
Technologies from Japan, the United States, and other nations are competing and collaborating to accelerate development toward "quiet supersonic aircraft." JAXA's Project Manager Yoshikazu Makino predicts that quiet passenger aircraft with sonic boom reduction technology could begin operations "as early as the 2040s."
The Future Supersonic Travel Promises
Current passenger aircraft cruise at approximately Mach 0.8, requiring over 12 hours to travel from Japan to Europe or North America. Supersonic aircraft could cut this to about 6 hours, energizing business and tourism while enabling faster emergency response during disasters. Flight times under 6 hours would also reduce the risk of deep vein thrombosis (economy class syndrome).
JAXA's envisioned small supersonic airliner would cruise at Mach 1.6, carry 50 passengers, and have a range exceeding 6,300 kilometers. The day when Tokyo connects to Hawaii or Singapore at supersonic speeds may not be far off.
Japan's JAXA is working to break through the "noise barrier"—a challenge for the aviation industry since the Concorde era—using proprietary technology. While building cooperative relationships with NASA, Japanese innovations may contribute to setting global standards.
What discussions are happening about supersonic aircraft in your country? Would you want to travel internationally on a supersonic jet in the future? Let us know in the comments!
References
Reactions in Japan
I've been following JAXA's low sonic boom technology since the 2015 flight tests in Sweden. It's amazing to see how far they've come. Japanese aerospace tech standing alongside NASA is really exciting.
Controlling sonic booms through airframe design sounds simple but is incredibly difficult in practice. The design preventing shockwave coalescence is well thought out. The partnership with Mitsubishi Heavy Industries is reassuring.
Even if it's quieter, CO2 emissions will still increase. Environmental considerations seem insufficient. I wonder how they'll reconcile this with aviation industry decarbonization.
Robust low-boom design essentially prevents shockwave superposition to reduce pressure peaks. The theory is elegant, but I'm curious how well the effect holds up in real atmospheric turbulence conditions.
If we can reach New York in 6 hours, same-day business trips won't be a dream anymore. But with only 50 seats, getting a ticket might be tough... Probably not for ordinary folks like me.
Even if boom noise is halved, what about takeoff and landing noise? I live near Narita Airport, so I hope they're considering that aspect too.
As someone who never got to fly on Concorde, it would be amazing to travel on a supersonic airliner in my lifetime. If it launches in the 2040s, I might just make it.
With the H3 rocket having various issues, I have an image of JAXA projects not meeting budget and schedule. I want to watch whether they can really pull off the 2028 flight test.
The technical approach differences between NASA's X-59 are fascinating. Japan focuses on overall airframe shape optimization, while the US emphasizes the long nose. Looking forward to flight test results to see which works better.
6 hours to Europe! Long 12+ hour flights are tough with kids now, so supersonic would make family trips easier. But I'm worried about the price...
While being developed as civilian technology, this low-boom tech could naturally be applied militarily. Compatibility with stealth will likely be a future focus.
JAXA's strength lies in the empirical data accumulated steadily since 1997. With flight test projects decreasing globally, Japan's continued efforts have significant value.
The airframe looks beautiful in the CG images. The elongated nose and complex wing curves—this is what aerodynamic optimization looks like. Can't wait to photograph the real thing flying.
Participating in international joint development would be a big opportunity for Japan's aircraft industry. But given the Mitsubishi SpaceJet issues with Boeing, political hurdles seem high.
Honestly, I'd prefer cheaper airfares over supersonic jets. But I want to support it as a technical challenge. I want to be able to say 'Japan is amazing,' you know?
NASA's X-59 just achieved its first flight, but JAXA's 'robust low-boom' approach is interesting. The ability to reduce sonic booms even off-track might be something X-59 doesn't have. If international cooperation could combine both technologies, that would be incredible.
I had given up on supersonic travel since Concorde disappeared. With both Japan and the US advancing this technology, maybe I'll get to fly supersonic again in my lifetime! How many hours would it take from London to Tokyo?
From the German aviation industry's perspective, it's surprising that Japan has its own patented technology in this field. What is Airbus doing? Europe should seriously commit to supersonic development.
I'm worried about environmental impact. Even with reduced noise, supersonic flight consumes more fuel than regular flights, right? Are they considering combining this with SAF (sustainable aviation fuel)?
Flight tests in 2028, ICAO standards in 2031, commercial operations in the 2040s... It's still a long road. But Japanese research institutions often stick to their schedules, so I'm hopeful.
As a French person, I have special feelings about Concorde. It's bittersweet that Japan is trying to solve the noise issues that led to Concorde's failure, but the technological progress is remarkable.
If we could reach Europe from India in 6 hours, it would be revolutionary for the Indian diaspora. But will ticket prices be affordable for regular people? Concorde was only for the wealthy.
As an aerospace engineer, let me say JAXA's research is truly world-class. The accumulated knowledge from continuous demonstration experiments since 1997 is unmatched. If technology sharing with X-59 happens, the entire industry advances.
Currently 9 hours from Australia to Japan. Supersonic would cut it to about 4 hours? It would change the concept of business trips and boost tourism. I think there'd be demand for Australia-Japan routes.
I'm from Poland living in the US, and if transatlantic flights become 3 hours, I could visit home multiple times a year! I wholeheartedly support the commercialization of supersonic technology.
From South America's perspective, being able to reach anywhere in the world within half a day is dreamlike. But routes will probably start with major US and Asian cities, with South America coming later.
China must be advancing supersonic passenger research too. Beyond Japan and the US, I'm curious about China's progress. There will likely be political maneuvering over which country's technology gets adopted for international standards.
I know Japan's flight tests were conducted at Esrange in Sweden. The Nordic countries have played an important role as testing grounds for supersonic research. I hope international cooperation continues.
Commercial operations in the 2040s? More technological breakthroughs will be needed by then, and I question whether airlines can build profitable business models. Better not to get our hopes up too high.
Currently about 10 hours from Dubai to Tokyo. If supersonic cuts it to 5 hours, business exchanges between the Middle East and Asia would accelerate rapidly. Dubai's position as an aviation hub might change too.