Aerospace startup Hermeus 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. Credit: Courtesy Hermeus.

It’s name is Quarterhorse, and some day, it will be able to fly defense higher-ups from New York to Paris in just 90 minutes, instead of more than the 7 hours today on regular jets.

And that is all because Hermeus, a hypersonic plane startup based in Doraville, Ga., impressed US Air Force, Department of Defense and NASA officials following a US$1.5 contract for the autonomous (yes, autonomous) high-speed aircraft concept.

They must have done one hell of a job, because the Air Force just handed them US$60 million for flight testing.

The contract allows three years to do that and develop, build and test a concept aircraft that can go five times the speed of sound (3,300 mph/Mach 5), The Atlanta Journal-Constitution reported.

On Twitter, Hermeus chief operations officer Skyler Shuford said that the prototype aircraft “Quarterhorse” would be flown unmanned to eliminate risk.

The Air Force said the contract is an effort by its Presidential and Executive Airlift Directorate to fuel a resurgence of high-speed passenger travel and to have options for “senior leader transport.”

The military branch also wants to speed development of technology it could use for future missions. One objective in the contract is for Hermeus to provide “wargaming inputs” for Air Force strategic analysis, the report said.

“We are transforming the Air and Space Force into an early-stage ‘investor’ that leverages private capital, accelerates commercialization of technology and grows the number of companies,” said Nathan Diller, director of the Air Force Research Laboratory technology directorate.

Anticipated to fly by the end of 2022, Quarterhorse will be used to validate Hermeus’s turbine-based combined cycle (TBCC) engine that is based on the GE J85, AINonline reported.

The Hermeus Mach 5 prototype engine undergoes testing at the company’s facility at Doraville, Georgia. Credit: Courtesy Hermeus.

Hermeus has retained a half-dozen more GE J85s as it proceeds with its development work and “we now have all the turbojet engines we need to complete our first aircraft development program with an iterative, hardware-rich approach.”

While some experts argue that it is impossible to flight test a TBCC engine across the full flight envelope for less than US$100 million, Hermeus is taking a different approach.

The company says it will be leveraging autonomous and reusable systems, ruthlessly focusing on requirements and engaging a hardware-rich program, the report said.

These three strategies allow the team to incrementally push the envelope, sometimes strategically to the point of failure in flight test, which accelerates learning.

Pushing more risk to flight allows Hermeus to move through the engineering lifecycle quickly, reducing program costs.

“Small business partnership is recognized by the US Air Force as an important component to driving innovation,” said Lt. Col. Joshua Burger, the Vector Initiative program manager who is spearheading the effort.

“Reducing risk in high-speed transport technologies, as we are doing with this contract, provides near-term and long-term benefits to both the US Air Force and the defense industrial base.

“We are very excited to see Hermeus translate their demonstrated successes in engine prototyping into flight systems.”

The company stressed its plans to take a dual military/civil path for the development of its hypersonic aircraft.

“While this partnership with the US Air Force underscores US Department of Defense interest in hypersonic aircraft, when paired with Hermeus’ 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.

It seems odd that it has taken mankind this long to master hypersonic flight, given that Air Force Major Robert White flew the X-15 research airplane at speeds over Mach 6 in 1961.

According to, the three big challenges facing Hermeus engineers are:

  • Heat: Hypersonic flight creates a tremendous amount of heat that needs to be managed with lightweight shields and thermally protected instruments;
  • Maneuverability: At hypersonic speeds, maneuverability demands extensive calculation and development;
  • Communication: Basic operations, like communications, become challenging when traveling at hypersonic speeds.

If Hermeus engineers can overcome these challenges, commercial hypersonic flights could become a reality.

Source: The Atlanta Journal-Constitution, AINonline, PR Newswire, Simple Flying