Technology & Innovation
Helix and Astro Mechanica Develop Duality Supersonic Engine
Helix and Astro Mechanica partner to create the Duality turboelectric engine for Mach 3 supersonic travel with hybrid propulsion.
In a major step toward reviving commercial supersonic travel, UK-based electric motor manufacturer Helix (formerly Integral Powertrain) has announced a strategic partnerships with California aerospace startups Astro Mechanica. The collaboration focuses on the development of the “Duality” engine, a turboelectric adaptive propulsion system designed to enable efficient flight at speeds up to Mach 3.
According to the official announcement from Helix, the partnership integrates their high-performance electric motors into Astro Mechanica’s proprietary engine architecture. This technology aims to solve the efficiency and range limitations that grounded previous supersonic aircraft like the Concorde. By utilizing a hybrid-electric approach, the companies hope to make supersonic travel affordable enough to compete with current business-class ticket prices.
The initiative is backed by significant industry interest and capital. Astro Mechanica has reportedly secured approximately $27 million in Series A funding, with investments including Andreessen Horowitz, Lowercarbon Capital, and United Airlines Ventures.
The core of this partnership is the “Duality” engine, which differs fundamentally from traditional jet propulsion. In standard jet engines, the compressor and turbine are mechanically linked on a single shaft, which limits efficiency across different speed regimes. The Duality engine replaces this mechanical link with an electric-aviation drivetrain.
As described in the technical details released by the companies, the Duality engine uses a gas turbine generator to produce electricity. This power is then directed to Helix electric motors, which drive the engine’s fan and compressor independently. This “decoupling” allows the engine to adapt its behavior based on the phase of flight:
The system is designed to operate on Liquefied Natural Gas (LNG) or synthetic methane. These fuels were selected for their lower cost and higher energy density compared to traditional jet fuel, further supporting the goal of economic viability.
Standard electric motors are typically too heavy for the power-to-weight ratios required in aerospace applications. Helix, known for supplying motors to high-performance automotive projects like the Lotus Evija and Aston Martin Valkyrie, is providing the specialized hardware needed to make the Duality engine feasible.
The current Gen 4 prototype of the engine utilizes four Helix SPX242-94 motors. According to the specifications provided:
Looking ahead to the Gen 5 production version, Helix aims to deliver even higher performance, targeting 900kW continuous power and speeds up to 20,000 rpm, all within a package weighing approximately 61.5 kg.
“Duality shows what becomes possible when you remove weight as the limiting factor.”
— Derek Jordanou-Bailey, Aerospace Chief Engineer at Helix
The aviation industry has long sought a successor to the Concorde, which was retired due to high operating costs and limited range. The Concorde burned massive amounts of fuel during taxi and takeoff, rendering it uneconomical for many routes. The Duality engine’s adaptive capability addresses this specific hurdle by optimizing efficiency at low speeds while maintaining the thrust required for supersonic cruise.
Astro Mechanica is targeting transpacific routes, such as San Francisco to Tokyo, with flight times under five hours. While commercial travel is the ultimate goal, the technology has immediate applications in the defense sector for high-speed drones and government transport.
The partnership between Helix and Astro Mechanica highlights a critical shift in the “green aviation” narrative. For years, the industry focus was heavily tilted toward pure electric flight (battery-powered). However, energy density limitations of current battery technology have restricted pure electric aircraft to short-range, low-speed/urban air mobility applications.
We observe that the industry is increasingly pivoting toward turboelectric and hybrid architectures for long-haul and high-speed applications. By using fuel (like LNG) for energy storage but electric motors for aerodynamic control, manufacturers can achieve the benefits of electrification, precise control, decoupled systems, and efficiency, without the weight penalty of massive battery packs. This approach may well be the bridge technology that finally makes supersonic commercial flight viable again.
Following a successful “hot-fire” test of the Gen 3 engine in October 2024, the companies are now focused on the Gen 4 prototype. Current projections estimate the first flight of a sub-scale demonstrator aircraft could occur between 2027 and 2028, with a target for commercial service entry in the 2030s.
Helix and Astro Mechanica Partner to Power New “Duality” Supersonic Engine
The Technology: A Turboelectric Adaptive Engine
Decoupling for Efficiency
Helix’s Role: High-Density Electric Power
Strategic Implications for Aviation
AirPro News Analysis
Timeline and Future Outlook
Sources
Photo Credit: Helix