Hypersonic passenger aircraft in a decade

But the design company Hermeus is still building its first unmanned combat aircraft, the first prototype of which was unveiled last week. Hermeus is planning to create the world’s fastest reusable hypersonic aircraft, intended for military use and passenger transport. The unique propulsion system of the Quarterhorse means that it will not need to be lifted into the air by a carrier aircraft, as is the case with NASA’s aircraft.

NASA’s hypersonic aircraft Hyper-X (X-43A) broke the speed record for a jet aircraft using air-intake technology on 16 November 2009, when it managed to accelerate to Mach 9.6, but was assisted by a carrier aircraft and a rocket. The aircraft was lifted to an altitude of 33,223 metres by a B52-B, followed by a Pegasus missile, and its own scramjet engine then operated for only 10 seconds before the craft crashed as planned into the Pacific Ocean. The experiment was also entered into the Guinness Book of World Records and, although NASA originally planned to achieve a speed of Mach 10 with the plane, it was perfectly suited to demonstrating the technology and, in NASA’s words, “a promising but unproven concept”.

Later, in the further development of hypersonic aircraft, in May 2010, the X-51A travelled in a B-52 to an altitude of 15 000 metres, as in the earlier tests, and from there it was propelled by the Army’s solid propellant booster rocket until it reached Mach 4.8. Only then did it fire its SJY61 scramjet engine, accelerating to Mach 5, a top speed of more than 6,000 km/h.

Hermeus’ different solution would allow the first and second phases to be omitted, i.e. the hypersonic aircraft could operate without the acceleration effect of the transport aircraft and the rocket, using a combined engine consisting of a normal turbofan and a thrust engine. At last week’s unveiling of the first, rudimentary prototype of the Quarterhorse, the company decided to throw in a surprise to entertain the public and not only unveil the aircraft, but also demonstrate the engine (which is also not yet the final version). At the event, which was held for investors, researchers, military and government officials, the engine was operated at maximum capacity, with afterburning, because, as Skyler Shuford, Hermeus’ operations director, said, the company’s staff “really like to light fires”.

However, the prototype will not yet use the engine’s capabilities in the air, as this model is not designed for flight, and its primary purpose is to demonstrate the manufacturing process itself, the assembly of the complex system and the hardware components. Despite the fact that the Quarterhorse is not yet airborne, the company is moving ahead quite quickly: the aircraft was built in four months from the time the plans were drawn up, the engine test facility was erected in 33 days and the first flight test could take place as early as the end of next year, according to Aviation International News. Unmanned aircraft will be built first, to test the viability of the propulsion system and later sold for military use, but the most important goal will be achieved after that, with a passenger version planned for sometime by the end of the decade or early 2030s.

AJ Piplica, CEO of Hermeus, told CNN what it will feel like to travel between continents in a hypersonic aircraft travelling at Mach 5. He said that the only difference between the current aircraft and the hypersonic version will be at the beginning of the journey, when passengers will feel the acceleration for 10-12 minutes rather than a few seconds, after which, at 30 000 metres, the ride will be smooth and pleasant.

Source : edition.cnn.com