Hermeus has reported a successful test flight of its unmanned Quarterhorse Mk 1 prototype at Edwards Air Force Base in California, USA. This is the company’s second step towards building a hypersonic aircraft capable of reaching speeds of Mach 5 (6,174 km/h).
The main purpose of testing the Quarterhorse Mk 1 prototype was to test the take-off and landing of an aircraft designed for speeds much higher than any other modern aircraft. This makes normal take-off and landing operations extremely difficult.
The Quarterhorse Mk 1 is the second in a series of four Quarterhorse prototypes. The first, Quarterhorse Mk 0, was a non-flying prototype solely to test the integration of major subsystems. The first flying prototype, Quarterhorse Mk 1, was built from scratch in just one year. The next prototype, Quarterhorse Mk 2, which is already being assembled at the Hermeus plant in Atlanta and will be the size of an F-16 fighter jet , is expected to reach supersonic speeds using the Chimera engine. The Quarterhorse Mk 3, with the Chimera II engine, is targeted to reach Mach 3.3 (3,540 km/h), making it faster than the legendary Lockheed SR-71 Blackbird (1966–1999) high-altitude reconnaissance aircraft.
Chimera is a hybrid of the Pratt & Whitney F100 turbofan (used on the F-15 Eagle, F-15E Strike Eagle, F-16 Fighting Falcon) with pre-cooling and its own Hermeus ramjet with pre-cooling. The turbofan part operates at speeds close to the speed of sound, with further acceleration the air flows are redirected to the ramjet.
In fact, founded in 2018, Hermeus plans to build both military and civilian hypersonic aircraft. The military version is called Darkhorse, the passenger version is called Halcyon. The projected speed is Mach 5, the flight range is 7,400 km. In 2020, Hermeus received funding from the US Air Force to study the possibility of using their future aircraft as Air Force One.