Aircraft Going After SR-71 Blackbird Speed Record Looks Like a Jet Engine on Wheels

If you've been watching our coverage of what's going on in this field, then you know the Quarterhorse is a product of a company called Hermeus and the precursor of what is described with no trace of modesty as the "world's fastest aircraft" – a piece of tech that will be called Darkhorse.

How fast will the Darkhorse be? Well, consider this. Back in 1976 the American SR-71 Blackbird spy plane reached speeds of Mach 3.3, or 2,193.2 mph (3,529.6 kph). In doing so it set an absolute speed record for a crewed aircraft flying in the atmosphere of our planet.

The Darkhorse, being hypersonic and all, will go over Mach 5 (3,800 mph/6,100 kph). Unlike the Blackbird, this aircraft is being designed not only with military uses in mind, but, believe it or not, civilian ones as well.

Before the Darkhorse gets here, however, Hermeus still has to test if its ideas work as advertised. That's what the Quarterhorses are for, and one of them, a vehicle called Mk 0, just completed its first series of major tests.

The procedure marked the first time a fully integrated vehicle in this family was subjected to validation procedures for "all major aircraft subsystems in a real-world environment." And the tests were indeed comprehensive, covering all major aspects of an aircraft, except for the actual flying.

Among other things, the machine proved it could be remotely controlled and can taxi safely down a runway, its comms systems were put to the test, and the pilot-in-the-loop steering and controls were put through their paces.

The tests took place at the Arnold Engineering Development Complex (AEDC) in Tullahoma, Tennessee, and are the first in a series that will culminate later this year with an actual flight of a Quarterhorse.

Hermeus plans to build four such prototypes, each of them adding new layers of complexity to the system. You may argue that coming up with three other prototypes and flying one by the end of the year may be a bit of a stretch, but you should consider the fact the Mk 0 was put together in just six months.

Mk 1 will be the first test flight vehicle (the one that will fly by the end of the year), and it will be used to test remote-controlled takeoff and landing. Mk 2 is the one meant to break the sound barrier, and go to speeds just below Mach 3. The final Quarterhorse, Mk 3, will be used to demo turbojet to ramjet transition and go after the record set by the Blackbird. It's unclear exactly how this attempt will be made.

At the time of writing the Quarterhorse family of vehicles is meant to use General Electric-supplied engines, with thrust levels sitting at 5,000 pounds.

The Quarterhorse was selected at the end of last year by the Defense Innovation Unit (DIU) to be part of the High-Cadence Airborne Testing Capabilities (HyAT) program, which also includes the DART AE made by Australian company Hypersonix, Rocket Lab's Hypersonic Accelerator Suborbital Test Electron (HASTE), and an unnamed drone made by Fenix Space.