Castelion, a cutting-edge defense technology company working to restore America’s conventional deterrence capability, announced today it raised $350 million in Series B financing, positioning the company to directly advance a top Pentagon modernization priority: hypersonic munitions production at scale.

The Series B round was led by Altimeter Capital and Lightspeed Venture Partners, with participation from Lavrock Ventures, Andreessen Horowitz, General Catalyst, First In, Space VC, Cantos, BlueYard, Avenir, Champion Hill, and Interlagos.