Accelerating the Future of Hypersonic Aviation

Hermeus is an aerospace and defense technology company developing hypersonic aircraft quickly and cost-effectively by combining a hardware-rich, iterative approach with modern computing and autonomy. Founded in 2018 by AJ Piplica (CEO), Skyler Shuford (COO), Glenn Case (CTO), and Mike Smayda (CPO), the company is headquartered in Atlanta, Georgia. Hermeus aims to revolutionize air travel by developing aircraft capable of speeds exceeding Mach 5, significantly reducing flight times for both military and commercial applications.

Technological Innovations

Chimera Engine

At the heart of Hermeus’ hypersonic ambitions lies the Chimera engine, a turbine-based combined cycle (TBCC) propulsion system. This innovative engine integrates a turbojet and a ramjet, allowing seamless transition from takeoff to hypersonic speeds. The turbojet operates at lower speeds, while the ramjet takes over at higher velocities, enabling efficient propulsion across a broad speed range. In November 2022, Hermeus successfully tested the Chimera engine, marking a significant milestone in hypersonic propulsion development.

High Enthalpy Air-Breathing Test Facility (HEAT)

To support the development and testing of hypersonic technologies, Hermeus invested $135 million in constructing the High Enthalpy Air-Breathing Test Facility (HEAT) at Cecil Airport in Jacksonville, Florida. This state-of-the-art facility is designed to test various engines, including the Chimera and the Pratt & Whitney F100, under high-temperature and high-speed conditions. The HEAT facility plays a crucial role in advancing the United States’ capabilities in air-breathing hypersonic engine testing.

Aircraft Development Programs

Quarterhorse

Quarterhorse is Hermeus’ experimental aircraft program aimed at demonstrating high-speed takeoff and landing capabilities. The program follows a phased development approach:

• Mk 0: A non-flying prototype used to validate major aircraft subsystems.
• Mk 1: An uncrewed, remotely piloted aircraft powered by a GE J85 engine. Its primary mission is to demonstrate high-speed takeoff and landing. In May 2025, the Mk 1 completed its first flight at Edwards Air Force Base, marking a significant achievement in U.S. aircraft development.
• Mk 2: A supersonic version expected to reach speeds greater than Mach 2.5.
• Mk 3: Incorporates the Chimera II propulsion system, targeting speeds faster than Mach 3.3.

Darkhorse

Darkhorse is an uncrewed hypersonic military jet intended for mass production. Designed for the defense market, it aims to provide rapid response capabilities and support various military missions.

Halcyon

Halcyon is Hermeus’ planned hypersonic passenger jet, envisioned to fly from New York to London in just 90 minutes. The aircraft will utilize the Chimera engine, enabling it to reach speeds of Mach 5. With over 125 routes planned, primarily over the sea to avoid sonic booms over land, Halcyon aims to revolutionize commercial air travel by the end of the decade.

Strategic Partnerships and Funding

Hermeus has secured significant funding and established strategic partnerships to advance its hypersonic aircraft development:

• Series B Funding: In March 2022, Hermeus raised $100 million in a Series B funding round led by Sam Altman, with participation from Founders Fund, In-Q-Tel, Khosla Ventures, Canaan Partners, and Bling Capital.
• Defense Innovation Unit (DIU): Hermeus has been awarded a contract by the DIU to mature hypersonic aircraft subsystem and mission system technology. The company will utilize its Quarterhorse prototype to support technical maturation and risk reduction for future hypersonic aircraft.
• U.S. Air Force Contracts: Hermeus received a $1.5 million contract from the U.S. Air Force in 2020, followed by a $60 million deal in 2021 to support the Quarterhorse flight test program. Additionally, the Air Force selected Hermeus for its Advanced Battle Management System (ABMS) contract, which has a $950 million ceiling.

Future Outlook

Hermeus is on a mission to operationalize hypersonic aircraft, with plans to:

• Continue testing and refining the Quarterhorse program, leading to the development of Darkhorse and Halcyon.
• Expand the HEAT facility to support advanced engine testing and development.
• Collaborate with government agencies and private investors to secure additional funding and partnerships.
• Achieve commercial hypersonic flight capabilities by the end of the decade, transforming both military and civilian aviation.

By combining innovative engineering, strategic partnerships, and a clear vision, Hermeus is poised to redefine the future of air travel.