Hermeus Hits $1B Valuation With $350M Funding for Hypersonic Aircraft Development

Quick Facts

• Hermeus raised $350 million ($200M equity, $150M debt) at a $1 billion valuation
• The company completed two successful test flights with its Quarterhorse aircraft in 2026
• Total funding now exceeds $500 million as defense tech investment surged to $49.1 billion globally

Hermeus raised $350 million in funding that pushes the hypersonic aircraft startup’s valuation to $1 billion. The Los Angeles-based company secured $200 million in equity financing led by Khosla Ventures, with the remaining $150 million coming from debt financing.

Existing investors Canaan Partners, Founders Fund, In-Q-Tel, and RTX Ventures participated in the round. New investors include Cox Enterprises, Destiny Tech100, and Socium Ventures. The funding brings Hermeus’ total capital raised to over $500 million.

The company achieved two successful test flights in 2026 with its Quarterhorse aircraft. The Mk 2.1 variant completed its maiden flight at Spaceport America in February, less than a year after the Mk 1’s first flight. The aircraft is sized like an F-16 and powered by a modified Pratt & Whitney F100 engine.

“Speed is life for us,” said CEO AJ Piplica. “This new funding lets us build multiple aircraft at the same time and scale our manufacturing capabilities, adding more hardware richness and robustness to our program.”

Hermeus modified its technical approach after partnering with RTX subsidiary Pratt & Whitney. The company added a precooler to the standard F100 engine, which lowers incoming air temperature to prevent engine parts from melting and improves efficiency. The Quarterhorse Mk 2 will fly with this engine combination and target speeds greater than Mach 2.5.

The funding comes during a defense tech investment boom. Defense-technology startups raised a record $49.1 billion in venture capital deals in 2025, up from $27.2 billion the previous year, according to CB Insights. Equity funding more than doubled to $17.9 billion from $7.3 billion in 2024.

Hermeus follows an iterative development approach, building one aircraft per year to unlock specific technical challenges on the path to Mach 5 hypersonic flight. The company operates facilities in El Segundo, California for prototyping and Atlanta for production. Its workforce approaches 300 employees.

The startup competes with established defense contractors like Lockheed Martin, Raytheon Technologies, Northrop Grumman, and Boeing in the hypersonic market. The U.S. military spends more than $2.6 billion annually on hypersonic capabilities, with projections exceeding $4 billion by 2025.

In-Q-Tel, the venture arm for the U.S. intelligence community, participated in the funding round, signaling government interest in hypersonic technology development.

Read more: Hypersonic aircraft startup Hermeus raises $350M at $1B valuation