Hermeus to Fly Hypersonic Small Vehicle Next Year

Aerospace start-up Hermeus, which landed a U.S. Air Force contract for the initial development of a hypersonic business jet for presidential travel, has signed a $60 million follow-up partnership agreement with the service to flight test its Quarterhorse unmanned small-sized vehicle as early as next year as it progresses toward completion of a full-scale passenger aircraft by the end of the decade.

Anticipated to fly by the end of 2022, Quarterhorse will be used to validate Hermeus’s turbine-based combined cycle (TBBC) engine, which is based on the GE J85. The aircraft will test speeds between Mach 3 and Mach 5. Hermeus has retained a half-dozen more GE J85s as it proceeds with its development work, and says “we now have all the turbojet engines we need to complete our first aircraft development program with an iterative, hardware-rich approach.”

Hermeus, which will build Quarterhorse at its recently established factory in Atlanta, has already cut metal for the vehicle. Company executives said that by using an autonomous vehicle, Hermeus is derisking this stage of the flight testing.

Plans call for following with a midsize vehicle that will be used for flight testing for cargo purposes around 2025 and that will have a longer range and more capable environmental control. That vehicle will be used to help provide a basis for MRO needs before the company proceeds to a passenger version. The planned 20-seat passenger aircraft is targeted for FAA certification in 2029.

The funding through the AFWERX Strategic Funding Increase (STRATFI) program will see the aircraft through the first flight, company executives said. STRATFI is led by the Presidential and Executive Airlift Directorate under a collaboration that includes support from the Air Force Research Laboratory.

“Small business partnership is recognized by the U.S. Air Force as an important component to driving innovation. Reducing risk in high-speed transport technologies, as we are doing with this contract, provides near-term and long-term benefits to both the U.S. Air Force and the defense industrial base,” said Lt. Col. Joshua Burger, the Vector Initiative program manager who is spearheading the effort. “We are very excited to see Hermeus translate their demonstrated successes in engine prototyping into flight systems.”

Hermeus acknowledged the costs involved in testing a TBCC engine across a full flight envelope but it maintained that by taking a different approach that leverages autonomous and reusable systems, it can achieve its flight test goals and accelerate the learning curve. “Pushing more risk to flight allows Hermeus to move through the engineering lifecycle quickly, reducing programmatic costs,” the company said. “When exploring beyond the speeds that airbreathing aircraft have flown before, learning must come through testing in the real world.”

The company emphasized its plans to take a dual military/civil path for the development of its hypersonic aircraft. “While this partnership with the U.S. Air Force underscores U.S. Department of Defense interest in hypersonic aircraft, when paired with Hermeus's partnership with NASA announced in February 2021, it is clear that there are both commercial and defense applications for what we're building," said Hermeus CEO and co-founder AJ Piplica.