Defence tech startups are rapidly gaining traction as governments and private investors pour funding into next-gen military and security innovations. Now, California-based Castelion, a defence manufacturer working to reduce the cost and schedule required to field new long-range strike weapons, has landed $100 million in funding. The $70 million in Series A funding was led by Lightspeed Venture Partners (which recently backed Neko Health and Whatnot) with participation from a16z, Lavrock Ventures, Cantos, First In, BlueYard Capital and Interlagos. Another $30 million in venture debt came from Silicon Valley Bank. The funding follows a $14.2 million seed funding and various Small Business Innovation Research contracts from US military services.The company will use this funding to scale production facilities, increase prototype testing, and support a capability demonstration of its first hypersonic weapon.
Founded by SpaceX veterans
Castelion was founded in 2022 in El Segundo by Sean Pitt, former director of commercial sales at SpaceX and Andrew Kreitz, the former senior finance manager at SpaceX. Its team includes advisors Mike Griffin and Lisa Porter, who held senior Pentagon positions during the first Trump administration.It has designed, built, and flown internally developed solid rocket motors, low-cost missile avionics, and hypersonic thermal protection material for internal development and industry use, successfully executing three internal flight tests in less than a month.
Innovation at hypersonic speeds
The company seeks to disrupt the hypersonic weapons market by incorporating commercial space industry practices into missile manufacturing. Hypersonic missiles, capable of travelling over five times the speed of sound while manoeuvring mid-flight, have become a top priority for the Pentagon as China and Russia advance their own capabilities. These weapons merge the speed of ballistic missiles with the agility of cruise missiles, operating in the upper atmosphere at altitudes between 40-100 kilometres. Their ability to strike hardened or time-sensitive targets with conventional warheads while maintaining manoeuvrability makes them highly challenging to intercept.
What makes its approach unique?
Castelion is advancing deterrence for America and its allies by developing mass-producible hypersonic long-range strike weapons. Given the evolving threat landscape, speed and innovation are essential to delivering these capabilities on operationally relevant timelines, traditional development and production models simply won’t keep up. To achieve both low cost and rapid deployment, the company prioritises mass production, vertical integration for schedule control, and rapid iterative design cycles with modern manufacturing techniques. By avoiding overly complex designs, embracing agile hardware development, and focusing on cost and manufacturability, the company can field advanced capabilities in months rather than decades.
