Castelion

Overview

Castelion develops hypersonic strike weapons designed around commercial parts and rapid iteration, aiming to field them in far larger numbers than traditional programs. Its founders left SpaceX in late 2022 to apply launch-industry test cadence to missile development.

Impact

• Positions itself as a new-entrant supplier to the US defense industrial base

Funding

At least: $100M seed, $350M Series B (2025), $1B Series C (Aug 2026). Reported valuation: $13B (Aug 2026).

Disclosed funding is the sum of publicly reported rounds found in the sources below. It is a floor, not a complete total.