Hermeus completes Quarterhorse subsystem vehicle ground testing

Quarterhorse Mk 0, Hermeus' ‘dynamic iron bird'. (Hermeus)

Hermeus has completed tests of its first Quarterhorse hypersonic unmanned aerial vehicle (UAV) – a ground test article dubbed “Mk 0”, according to a statement by the company. The ground tests are intended to pave the way for flight-testing later in 2024.

Testing of what the company calls its “dynamic iron bird” took place at the US Air Force's (USAF's) Arnold Engineering Development Complex in Tullahoma, Tennessee, over a 37-day time span. Among other tasks, the craft demonstrated ground-handling qualities of integrated subsystems, taxiing, and lost-link behaviour.

The vehicle was designed and constructed in six months, according to Hermeus.

“This was the first time our flight test team had an opportunity to work in a deployed test campaign with external stakeholders,” Don Kaderbek, Hermeus' vice-president of test, said in a statement. “The more the team works together and establishes their battle rhythm, the smoother flight-testing will go.”

The Quarterhorse Mk 0 is the first of a planned four test articles, three of which are intended to be flightworthy. The follow-ons, designated Mks 1 to 3, are intended to demonstrate higher speeds and more complex manoeuvres, culminating in hypersonic flight. A first flight is planned before the end of 2024.

Quarterhorse is intended to serve as a test vehicle for hypersonic technologies. The UAV is powered by a turbine-based combined cycle (TBCC) engine, based around the General Electric J85 engine. In November 2023 Hermeus received a grant from the Defense Innovation Unit to mature its hypersonic propulsion technology and has received funding from the USAF and Raytheon in the past.

Hermeus' Quarterhorse is one of a stable of planned hypersonic vehicles, intended to prove TBCC technology for the larger, defence-marketed Darkhorse.