Castelion has raised $350 million in Series B financing to scale the domestic production of affordable hypersonic weapons, advancing one of the Pentagon’s highest modernization priorities. The Series B round was led by Altimeter Capital and Lightspeed Venture Partners, with additional participation from Lavrock Ventures, Andreessen Horowitz, General Catalyst, First In, Space VC, Cantos, BlueYard, Avenir, Champion Hill, and Interlagos.
The funding strengthens the company’s position within the rapidly evolving defense industrial base as demand grows for high-volume, cost-effective hypersonic systems capable of addressing global strategic threats.
The California-based defense technology company, founded to rebuild America’s conventional deterrence capacity, will use the capital to complete major technical milestones and expand manufacturing. These include integrating its first hypersonic weapon, Blackbeard, with U.S. Army and U.S. Navy operational platforms, accelerating development at its new production and final-assembly facility, Project Ranger, and supporting multi-service platform testing scheduled for 2026.
Project Ranger, located on a 1,000-acre campus in Sandoval County, New Mexico, is positioned to become one of the nation’s largest solid rocket motor production sites. Castelion expects the facility to produce thousands of Blackbeard missiles annually while creating hundreds of high-skilled industrial jobs. The company’s manufacturing roadmap also includes maintaining a fast-paced testing cadence in 2026 and maturing a second hypersonic product line that leverages shared subsystems to minimize cost and accelerate deployment timelines.
Castelion’s strategy is focused on compressing weapon development cycles from years to months, replacing historically limited, high-cost production models with scalable architectures built for repeatable testing and mass manufacturing. The company conducted more than 20 development flight tests in 2025, validating numerous subsystems, including solid rocket motors, flight computers, seekers, control actuation systems, thermal protection materials, and mission software. This test throughput aims to establish the industrial foundation needed for high-rate missile output rather than narrowly produced inventory.
Headquartered in Torrance, California, Castelion operates manufacturing facilities in New Mexico, Texas, and California. Blackbeard represents the first U.S. hypersonic system engineered from the outset for commercial cost structures, industrial-rate production, and continuous flight test iteration.
KEY QUOTES
“Blackbeard helps close America’s hypersonic capability gap against China and Russia. This funding lets us build fast, test often, and produce at volumes that matter in the real world.”
Bryon Hargis, CEO and Co-Founder of Castelion
“Castelion was founded by a special team of SpaceX alumni who, in just 2.5 years, took a clean-sheet hypersonic from concept to 25+ flight tests and major integration contracts. We’re leading this round because of what they’ve achieved in record time and so they can rapidly scale production of one of the U.S. Department of War’s most critical capabilities: affordable, mass-produced hypersonics, from hundreds to thousands of missiles per year.”
Erik Kriessmann, Partner at Altimeter Capital
“Castelion isn’t just building missiles; they’re rebuilding America’s industrial depth. This team has proven they can move from blank sheet design to hardware under test faster than anyone thought possible.”
Connor Love, Partner at Lightspeed Venture Partners
“Lavrock invests in critical technologies that strengthen America’s national security, and Castelion is doing exactly that. Hypersonics only matter if you can build them at scale. Castelion’s team understands that, and they’re engineering a production-ready capability designed for real-world manufacturing and deployment. We’re proud to be early backers of a team focused on delivering capacity, not just concepts.”
Alex Poulin, Partner at Lavrock Ventures
“Hypersonic weapons capacity will shape great power competition for generations. China recognized this a decade ago and deployed at scale. Castelion leads America’s arsenal renewal with the speed, cost advantage, and volume at scaled production that our nation demands.”
Katherine Boyle, General Partner at Andreessen Horowitz
“Castelion is transforming the economics of our defense industrial base. Modern deterrence demands hypersonic capability at a pace, scale and cost that the U.S. has never seen.”
Paul Kwan, Managing Director, General Catalyst
