Hermeus has completed a 1:1 demonstrator flight (sized like an F-16) and is planning a supersonic iteration for the next aircraft, with a third aircraft in development to accelerate progress toward Mach 3 and beyond.

With a new capital raise, the company will move from prototyping to mission-ready aircraft, focusing on fast unmanned platforms, including continued work on the Quarterhorse Mk 2.1 and pursuing sustained supersonic capabilities.

Hermeus concentrates on unmanned, supersonic and hypersonic aircraft, advancing multiple Quarterhorse prototypes aimed at Mach 3 and beyond.

Co-founder and CEO AJ Piplica says the debt portion of the financing helps maintain control while scaling manufacturing and hardware development.

The Series C round is led by returning investor Khosla Ventures, with participation from NASA, the US Air Force, Sam Altman, and other backers; the company employs over 275 people across Atlanta, Los Angeles, Washington, and Jacksonville.

Hermes is actively hiring engineers in Los Angeles and Atlanta to support expanded production and manufacturing capabilities.

The Series C totals $350 million in equity and debt combined, lifting total capital raised to over $500 million to advance next-generation defense aviation.

Funds will expand manufacturing capabilities and headcount, with Piplica likening Hermeus’s approach to SpaceX’s rapid build-test-fail-repeat, while highlighting talent scarcity as a key constraint.

Hermeus plans to move its headquarters to El Segundo, California, while maintaining an Atlanta facility for manufacturing; no layoffs in Atlanta are planned.

El Segundo’s aerospace ecosystem and incentives, including Hackman Capital Partners’ 30-acre complex housing Hermeus, support a broader regional growth in aviation and defense tech alongside legacy contractors and startups.

New funding will support growing the team toward about 300 engineers, expanding manufacturing, and advancing government contracts and regulatory testing.

The funding will enable near-300-employee expansion and accelerated development of multiple aircraft programs amid ongoing test flights and risk management.