Castelion

Castelion builds low-cost hypersonic strike missiles using a manufacturing playbook borrowed from SpaceX , where several of its founders worked: rapid iteration, deep vertical integration, and high-volume production rather than bespoke, hand-built weapons. The company was founded in 2022 and emerged from stealth in October 2023; it is led by co-founder and chief executive Bryon Hargis, who previously ran national-security satellite business development at SpaceX, and is based in Torrance, California. It makes its own solid rocket motors and flight computers in-house.

Its flagship weapon, Blackbeard, is a tactical hypersonic missile flying above Mach 5, engineered to be cheap enough to field in quantity — a sharp contrast with the multi-million-dollar, low-rate hypersonics that have defined the field. A ground-launched variant, Blackbeard GL, is designed to fire from the Army’s HIMARS launchers, and an air-launched version is aimed at the Navy’s F/A-18 Super Hornet.

The defence pipeline has grown quickly. Castelion holds research awards from the Air Force Research Laboratory and Naval Air Systems Command, and the Army’s FY2026 budget requested about $25 million for Blackbeard Ground Launch prototyping. In February 2026 the company won a roughly $49.9 million Navy contract to move Blackbeard from prototype toward early operational capability, and in May 2026 it signed a framework agreement with the Department of War guaranteeing a minimum of 500 missiles a year once the weapon is validated — described as the first production agreement of its kind for a low-cost hypersonic. To supply that volume it is building Project Ranger, a solid-rocket-motor manufacturing campus in New Mexico.

Investors have backed the thesis aggressively. After a $14.2 million seed and a roughly $100 million Series A in January 2025 led by Lightspeed Venture Partners, the company raised a $350 million Series B in December 2025, led by Altimeter Capital and Lightspeed with backing from Andreessen Horowitz and General Catalyst, taking total funding to around $450 million.