United Airlines has made a new investment in the supersonic aviation sector through its venture capital division, United Airlines Ventures. The company announced it is investing in Astro Mechanica, a startup focused on developing advanced propulsion technology for future high-speed commercial flights.
Astro Mechanica, established in 2021, is working on a turbo-electric adaptive engine that can shift between turbofan, turbojet, and ramjet modes. This design draws comparisons to engines used on historic high-speed aircraft like the Lockheed SR-71 Blackbird. The startup’s planned engine, named Duality, uses a hybrid-electric setup to address varying performance needs during different stages of flight. While Astro Mechanica is focusing solely on engine production and does not currently have customers, it is also designing its own supersonic transport aircraft.
This move by United comes shortly after President Donald Trump signed an executive order in June 2025 repealing Federal Aviation Administration rules that had long banned civilian supersonic flights over land. The regulatory change could open up routes such as New York to Los Angeles for Mach 1+ travel.