Hermeus finishes ground tests for hypersonic Quarterhorse prototype, sets sights on Mach 5

The startup Hermeus reported successful ground tests of its Mk 0 prototype. According to their timeline, this lays the groundwork for the Mk 1 flight testing phase, scheduled for 2024. The ground tests unfolded over 37 days at the US Air Force's Arnold Engineering Development Complex in Tullahoma, Tennessee.

The Quarterhorse Mk1 prototype showcased the integration and coordination of its various subsystems. It demonstrated taxiing capabilities, behavior during connection loss, and how delays influence flight control. This achievement is impressive, considering the prototype was conceptualized and constructed in six months. Don Kaderbek, Vice President of Testing at Hermeus, offered insight on this milestone.

With ground testing off the to-do list, the team is now gearing up for Mk 1 flight tests, achieving speeds below Mach 3 (Mk 3) and ultimately reaching Mach 5 speed (Mk 4). If successful, Hermeus's ambition to hit speeds of Mach 5 (equivalent to 3802 miles per hour) could break the current flight speed record held by the legendary SR-71 Blackbird aircraft, which exceeded Mach 3.

In recognition of their potential, the startup has secured $ 60 million in funding from the US Air Force and various venture capital firms. This financial contribution will aid in propelling the Quarterhorse flight test program forward. In addition, Hermeus received a grant from the Defense Innovation Unit by the end of 2023, which is intended to further the development of hypersonic propulsion technology.

A modified version of the General Electric J85 engine powers the unmanned Quarterhorse. Moreover, the aircraft will require a highly durable, high-temperature-resistant fuselage coating—capable of withstanding temperatures up to 1832 degrees Fahrenheit. Should the project come to fruition, this jet could become a new addition to the US President's fleet.