In the serene lakeside town of Baar, Switzerland, a team of over 100 engineers at Sirius Aviation AG has been fervently engaged in an ambitious project since 2021. Their creation, the Sirius Jet, is set to soar up to 1,150 miles at speeds reaching 323 mph, boasting a clean liquid-hydrogen powertrain and a deflected vectored thrust system with 20 electric ducted fans.
In an attempt to rival Germany’s Lilium Jet, the Sirius Jet stands out as a hydrogen-powered alternative, promising higher-density energy storage and extended range. The Business version, accommodating three passengers, achieves the maximum 1,150-mile range, while the Millennium version, designed for commercial use with five passengers, offers a still impressive 650-mile range. This places Sirius in contention for lucrative routes such as LA to San Francisco, London to Berlin, Melbourne to Sydney, or Beijing to Seoul.
However, the journey to realizing this vision is no walk in the park. The Sirius Jet introduces a deflected-thrust system with 20 small electric ducted fans, raising concerns about energy efficiency during vertical takeoff and landing. Despite potential inefficiencies, running on hydrogen compensates for these drawbacks, given the ample onboard energy storage.
Yet, the liquid-hydrogen powertrain poses a substantial challenge. While hydrogen is recognized as a promising solution for clean short-range aviation, the certification and commercial use of aviation-grade hydrogen powertrains remain uncharted territory. Sirius’ decision to explore liquid hydrogen adds an extra layer of complexity, as the technology is still in its infancy, requiring extremely low temperatures throughout distribution, filling, and flight.
Sirius’s approach also differs from others in the industry, as it is developing its own liquid hydrogen powertrain alongside the monumental task of bringing the airframe and integrated aircraft into production. The lack of infrastructure for gaseous hydrogen further complicates the scenario.
Despite the high stakes, Sirius’s design is visually appealing, and the potential for liquid-hydrogen-powered electric VTOLs to play a significant role in the aviation landscape is undeniable. Success, however, hinges on finding investors willing to commit substantial funds without expecting immediate returns, a challenge exacerbated by the financial demands of the initial eVTOL wave.
The future of the Sirius Jet remains uncertain, but the team’s determination and innovation are commendable, offering a glimpse into the evolving frontier of hydrogen-powered aviation.