The Mjölnir engine, developed by New Frontier Aerospace, aims to revolutionize the field of hypersonic and orbital propulsion. Although its name alludes to mythology, it is an advanced engineering product whose true potential lies in its underlying technologies.
At the heart of its design is the full-flow staged combustion cycle, a solution previously used only in the most advanced engines, like SpaceX's Raptor. In this system, both the fuel and the oxidizer are first routed to separate pre-burners, which translates to higher efficiency and a longer component lifespan. The entire assembly is enclosed in a compact, 3D-printed housing, which lowers costs and shortens production time.
A key differentiator for the Mjölnir engine is its fuel. Instead of the commonly used RP-1 (kerosene) or hydrogen, it utilizes liquefied natural gas (LNG). LNG offers a compromise between energy density (35 MJ/liter) and ease of storage, while also being a cheaper and more environmentally friendly solution. Importantly, recent tests in Washington state, supported by NASA, have confirmed its stable operation.
The Mjölnir engine is intended to be the foundation for two flagship projects. The first is Pathfinder, an unmanned hypersonic vehicle scheduled for testing in 2026. The second is the Bifröst orbital transfer vehicle, which is set to transport payloads in low Earth orbit (LEO) starting in 2027. The success of these missions is crucial, as the full-flow staged combustion technology is extremely demanding due to the extreme pressures and temperatures its turbopumps must withstand.
Although New Frontier Aerospace is a startup—supported by NASA and the Pentagon—tackling technological challenges previously overcome only by industry giants, Mjölnir is a real contender for the engine of the future. It combines an innovative architecture, an environmentally friendly fuel (LNG), and flexible manufacturing. If the Pathfinder and Bifröst vehicle tests are successful, Mjölnir could become a key component of future military and commercial programs, setting a new direction for the development of aviation and astronautics.
