Castelion Raises $1 Billion to Scale Low-Cost Hypersonic Weapons

Defense startup Castelion has raised $1 billion in a Series C funding round, according to reporting from Ventureburn and SpaceNews. The company plans to use the capital to scale up production of low-cost hypersonic weapons.

Castelion was founded by former SpaceX executives, SpaceNews reported. Beyond a low-cost hypersonic weapon, the company is working toward a broader lineup that includes longer-range strike systems and missile defense weapons.

According to Ventureburn, Castelion is designing its missile systems for high-volume manufacturing from the start and building its core technologies in-house to control quality and cost. The company relies on rapid hardware iteration and tight vertical integration, an approach intended to lower unit costs and shorten flight testing timelines compared with traditional defense manufacturing, which can involve years of development and billions of dollars for a single missile system.