(CNN) -- Two decades ago, the era of supersonic commercial flight ended with the final landing of Concorde at an airfield in southwest England.
In recent years, numerous contenders to the throne, supersonic, hypersonic, hydrogen-powered, with anti-boom technology, have been buzzing, at least conceptually, but many of these projects that promised uninterrupted superfast travel have stalled, slowed down or suffered delays.
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Now, a new European hypersonic company is in the race, promising travel times as tempting as Frankfurt to Sydney in 4 hours and 15 minutes, or Memphis to Dubai in 3 hours and 30 minutes.
This is a visualization of the final concept of Destinus. Credit: Courtesy of Destinus
The Destinus concept consists of hydrogen-powered flight at five times the speed of sound, which would reduce the duration of the flight to less than a quarter of that of current commercial air travel.
Destinus, founded in 2021 with headquarters in Switzerland and a team of around 120 employees spread across Spain, France and Germany, is reaching its milestones rapidly. Its first two prototypes have made successful test flights and are about to start testing hydrogen-powered flights. Its third prototype, Destinus 3, will make its maiden flight later this year.
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Martina Löfqvist, the company's director of business development, spoke to CNN via video call to explain its model and why the team hopes it will usher in the new era of hypersonic travel.
"There are different ways to do it," says Löfqvist. While other top contenders in this field, such as Boom Supersonic, "focus more on the development of the models and understanding how it works and trying to make these piloted aircraft work, we go directly to autonomous flights." The strategy is to "develop smaller drones before scaling it into a large piloted or passenger-carrying aircraft."
Destinus chose hydrogen as a fuel because it is a clean, renewable energy source, increasingly cheaper to produce and able to help it realize its speed and long-range ambitions. Hydrogen-powered aviation is still in its infancy, and hydrogen jet engines are not yet used commercially. Airbus is developing a hydrogen jet engine that it says will begin flight testing in 2026.
Löfqvist explains: "We try to make our vehicles have a very, very long range: flying from Europe to Australia at Mach 5. Using kerosene means the vehicle would become quite heavy, whereas hydrogen is very light in comparison." Hydrogen also has higher energy density than traditional jet fuel.
The long-term goal is for the vehicle to run entirely on hydrogen and have zero emissions, but while hydrogen production continues to increase, their short-term plan is to power takeoff with Jet A, conventional aviation fuel, and then switch when they reach speeds of around Mach 3 "because hydrogen is not really useful or better than Jet A until you reach supersonic speeds."
The Destinus prototypes are "waverider-shaped" mixed-body aircraft, a hypersonic design first conceived in the 1950s but never making it to production, with the company's Swiss-French origins reflected in Alpine-inspired paint.
This now classic form "has been studied for many, many, many years," says Löfqvist. "The purpose of it is that you can ride on top of the shock waves that are generated from the vehicle itself. It's a pretty efficient way where you can use less fuel to fly through it because you have less air resistance."
Naturally, with each new prototype Destinus perfects and adjusts the design. The team expects that, in two decades, the spacecraft it is working with will be somewhat different from the models in current tests.
The next prototype, Destinus 3, will be supersonic and is expected to reach hydrogen-powered supersonic flight by 2024. "It's a pretty big vehicle," explains Löfqvist. "It's about the same size as the previous prototype (about 10 meters long), but it's 10 times heavier and probably 20 times more complex, both in terms of its structure and propulsion system."
This is Eiger, the company's second prototype. He managed to complete test trips in 2022. Credit: Courtesy of Destinus
The expected deadline is that in the 2030s the company can launch a smaller aircraft, with capacity for about 25 passengers, which will have some limitation in terms of autonomy and will be totally focused on business class customers.
By the 2040s, its full-scale version will have multiple classes, including economy. They hope that by then "hydrogen prices will drop significantly, so that then we can reduce flight prices, also significantly, for these ultra-long-haul flights."
The company's plans depend heavily on the vagaries of the hydrogen market, which Löfqvist freely admits he does not control, but experts inside and outside the company have warned that they expect prices to fall.
Last month, Destinus acquired Dutch company OPRA, which is now called Destinus Energy. "This means that we can have revenue as early as this year, because they already have gas turbines built and for sale. Now we will not only have the aerospace part of the hypersonic aircraft, but also some of these energy aspects within the company," says Löfqvist.
In addition to the private investment and public funding it has already secured, in April 2023 it secured grants worth $26.7 million (US$29.4 million) from the Government of Spain to expand its hydrogen propulsion capabilities, Destinus hopes that these additional revenues will help it address the challenges that other supersonic and hypersonic projects have faced and that have caused them to fall by the wayside. Löfqvist stresses that the company is committed to a "realistic" approach, "now that the financing environment is a little tougher".
Nevada-based Aerion, which was one of the top contenders in the race to be the first to build a supersonic passenger jet, went bankrupt in May 2021. The company stated that "in the current financial environment, it has proved enormously difficult to close the large planned and necessary new capital needs."
As for whether in the 2040s we will be riding hypersonic aircraft, having breakfast in Shanghai and arriving in São Paulo right after lunch, there may be some technological, environmental and financial hurdles to overcome before then. But there will be no shortage of those who try.