Castelion Raises $350 Million Series B to Scale Hypersonic Weapon Production

Dec 16, 2025
Castelion has secured $350 million in Series B funding to expand U.S. manufacturing and scale production of its hypersonic weapons, including integration of its Blackbeard system with Army and Navy platforms.

Castelion has raised $350 million in Series B funding to accelerate U.S. manufacturing and large-scale production of hypersonic weapons, announced in a press release. The financing supports the Pentagon's modernization goals for hypersonic munitions and will fund integration of Castelion’s first system, Blackbeard, with operational platforms from the U.S. Army and U.S. Navy.

The funding round was led by Altimeter Capital and Lightspeed Venture Partners, with participation from Lavrock Ventures, Andreessen Horowitz, General Catalyst, and others. The company will also use the capital to construct its production and assembly facility, called Project Ranger, and to conduct multi-service platform testing in 2026.

According to Castelion, the new funding enables it to meet key technical milestones and scale production to address national defense needs prioritized by the Pentagon.

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