United Airlines Invests in Supersonic Startup Astro Mechanica

United Airlines has recently announced that its venture capital arm, United Airlines Ventures, has made a significant investment in the supersonic aviation startup Astro Mechanica. This move showcases United’s strong commitment to the future of widespread supersonic flight, as the Chicago-based carrier has also placed orders for the Boom Overture Supersonic Transport.

The timing of this announcement is significant, as an executive order signed by US President Donald Trump in June 2025 has effectively repealed the decades-old FAA regulation prohibiting civilian supersonic flight over land. This opens up the possibility for coast-to-coast Mach 1+ routes in the future, and United is taking steps to invest more heavily in this field.

What Does Astro Mechanica Do?

Founded in 2021, Astro Mechanica is a startup that is developing a turbo-electric adaptive engine capable of switching between turbofan, turbojet, and ramjet modes. This concept is similar to the Pratt & Whitney J58 engine used in the Lockheed SR-71 Blackbird, which functioned as a turbojet at high speeds but acted more like a ramjet. The company is also working on its own supersonic transport, although details about the aircraft are still limited.

The aircraft, called Duality, will utilize a hybrid-electric architecture to meet the different performance requirements at various stages of flight. It is worth noting that Astro Mechanica is only producing the engine and has no current customers. In comparison, Boom is developing both the Overture airliner and its own engine in-house.

For United, investing in Astro Mechanica’s technology serves as both a hedge and an opportunity. With the Boom Overture still several years away and subject to various factors such as regulations, technology advancements, and infrastructure developments, having multiple options for propulsion technology allows the airline flexibility and access to emerging breakthroughs. This is similar to purchasing two competing aircraft models, such as the Airbus A320 and Boeing 737.

Regulations for Supersonic Flight

With the lifting of the ban on civilian supersonic flights through Trump’s executive order, the market for commercial supersonic transports is expected to grow significantly. Instead of being limited to over-water routes (primarily transatlantic flights due to the limited range of supersonic airliners), these planes can now fly over land, making it possible to serve high-demand routes such as New York to Los Angeles.

United currently holds 15 firm orders and 35 options (up to 50 orders total) for the Boom Overture. It is one of three airlines that have placed orders for the Overture, alongside Japan Airlines and American Airlines. This investment by United further demonstrates their commitment to the world of supersonic flight.

Airline

Firm Order

Options

American Airlines

20

40

Japan Airlines

0

20

United Airlines

15

35

Compared to the Concorde, Astro Mechanica’s Duality and Boom’s Symphony engine are designed to be