British defence group Cambridge Aerospace has raised $300mn to develop its missile and drone interceptor systems, valuing it at $3.4bn and cementing its status as one of the UK’s most valuable start-ups. The funding round, the first time Cambridge has announced a capital raise, was led by San Francisco-based DFJ Growth, a prominent backer of Elon Musk’s Space X. The deal takes total funding since its founding in 2024 to more than $630mn.

Cambridge plans to use the proceeds to scale up production of its two main systems: Starhammer, a rocket-powered interceptor missile for high-speed targets, and Skyhammer, a low-cost anti-drone and cruise missile interceptor. Skyhammer is already in production with plans to produce 2,500 a month by March next year. Starhammer is expected to come to market next year.

Unlike some defence tech peers, Cambridge has already received several contracts from the UK Ministry of Defence, including a multimillion-pound contract to supply Skyhammer to the British Armed Forces and Gulf partners. The company uses modern manufacturing methods like 3D printing and AI to produce interceptors at lower cost and greater volume, and has developed its own solid rocket motors, building Europe’s largest factory for them in Norfolk.