Hypersonic missile startup funding continues to surge as Castelion, a defence technology company headquartered in El Segundo, California, with additional operations in Allen and Midland, Texas, founded by former SpaceX engineers, prepares to close a $350 million Series B round. Other participants in the round include Battery Ventures and Pritzker Group.
This investment, which values the company in the billions, will accelerate Castelion’s mission to build low-cost, mass-producible hypersonic missiles—technology that is rapidly becoming central to future military capabilities. With this round, Castelion’s total capital raised now stands at approximately $450 million.
As global military competition intensifies, especially between the US and China, the focus is shifting from sheer firepower to the speed and precision offered by hypersonic weapons. Castelion’s approach is to move beyond early-stage R&D and scale up production of tactical hypersonic missiles, aiming to secure a decisive edge for the US and its allies.
Former SpaceX talent steers Castelion into national defence spotlight
Castelion’s founding team includes Bryon Hargis (Co-Founder & CEO), Sean Pitt (Co-Founder & COO), and Andrew Kreitz (Co-Founder & CFO). Hargis is a 20-year veteran of the aerospace and defence industry, most recently leading sales and business development for SpaceX’s National Security satellite programs, building a multi-billion-dollar sales pipeline in under five years. He holds an M.S. in Applied Physics from Johns Hopkins University and a B.S. in Mechanical Engineering from the Georgia Institute of Technology. Pitt previously led SpaceX’s launch and human spaceflight sales in Europe, securing over $1.25 billion in export deals with satellite operators and allied defence agencies. Kreitz managed SpaceX’s launch forecasting and government cost proposals and served as a Vice President at Goldman Sachs, executing over $10 billion in aerospace and defence acquisitions.
The company was founded in November 2022.
From stealth to scale: testing, awards, and early government contracts
After emerging from stealth in late 2023, Castelion adopted a high-velocity model inspired by SpaceX: rapid iteration, frequent testing, and aggressive scaling. The company’s team has grown to 80–100 employees. In March 2024, Castelion successfully tested its hypersonic vehicle in the Mojave Desert, marking a major milestone. Castelion has already secured grants from the Air Force Research Laboratory and Naval Air Systems Command, and is expanding its manufacturing footprint in Texas.
The momentum continued in June 2025, when the U.S. Army included Castelion in its fiscal year 2026 budget request. Under Project HX3, the Army is seeking $25 million to support the development of Castelion’s Blackbeard Ground Launch (GL) missile — a more affordable hypersonic alternative designed for broad deployment.
The Army’s Rapid Capabilities and Critical Technologies Office (RCCTO) is overseeing development, following a May 2025 Acquisition Decision Memorandum and a validated Abbreviated Capability Development Document. Blackbeard GL is engineered to deliver about 80% of the capability of legacy systems like the Precision Strike Missile (PrSM) Increment 4, but at a significantly lower cost.
Long-term plans include multi-phase government deals and new launcher tech
Pending final approval from President Trump, the Army’s plan will unfold in two phases. First, Castelion will deliver a prototype proof-of-concept, slated for early 2026 demonstration. If successful, the company will follow up with 10 test missiles in 2027. These will be fired using standard High Mobility Artillery Rocket Systems, though Blackbeard is also being built to support a new autonomous-capable launcher.
If field trials meet expectations, Castelion could move into full-scale delivery by early 2028. That outcome would establish the company as a competitive supplier in the rapidly evolving hypersonics market, traditionally dominated by major aerospace contractors.
What sets Castelion apart from traditional defence players
While established aerospace firms continue to develop long-range hypersonic missiles, Castelion’s pitch is different: it prioritises cost-efficiency and manufacturing speed over marginal performance gains. This trade-off resonates with military buyers eager to field more missiles faster, even if it means sacrificing some speed or range. The approach gives Castelion a unique position in a defence landscape hungry for innovation and agility.
Ready for launch: The future of hypersonics may hinge on the speed of execution
With the US defence establishment under pressure to close the hypersonic gap with China, Castelion’s agile, integrated model offers a compelling solution. The hypersonic missile startup funding round not only brings scale within reach but also reaffirms investor appetite for national security tech with commercial DNA.
As Castelion prepares for the next test phase and potential mass deployment, its trajectory could reshape the economics and strategy of missile production, operating at Mach 5 and beyond.
