Move over supersonic flight and pave way for hypersonic transport that can zip you from NYC to London in under an hour. Hermeus Quarterhorse can fly at five time Mach 1 or five times the speed of sound. At that incredible speed travelling from NYC to London can be accomplished in less than an hour of air time. Last week, the company was awarded $60 million from the US Air Force to begin testing of the aircraft.
Hermeus Quarterhorse is expected to reach top speeds of Mach 5.5 or 4,219 mph which would make it the fastest reusable aircraft on the planet. This incredible speed will be accomplished from a unique engine design, a turbine-based combined cycle (TBCC) propulsion system. These engines use a standard jet engine for takeoff and landing and to achieve enough speed during flight to force air into a second turbine known as a ramjet or scramjet which produces more power but requires higher air flow speeds to ignite. The secret is fine-tuning these systems to transition smoothly between turbines and scramjet to achieve hypersonic speed.
The project so far looks promising, in nine months, the company designed, built and tested the engine, which is based on the General Electric J85 turbo jet. Since the aircraft will be operated autonomously, there will be no need for human test pilots thereby reducing the time it would take to get a safe prototype in the air for testing. A smaller scaled-down version is set for testing in 2023, a mid-size cargo-carrying version in 2025 and a larger commercial version in 2029.
While the company has plans for a cargo and commercial version, its partnership with the Department of Defense underscores the interest of the Air Force in Hypersonic aircraft and there might very well emerge a military application for the aircraft in the foreseeable future.