Since Concorde's retirement about 20 years ago, interest in supersonic flight has increased, and a number of ultra-rapid aircraft are currently in development. Airlines appear interested: United has already stated that it will start operating supersonic services in 2029. What about hypersonic travel, which occurs at Mach 5 and above (five times the speed of sound)? Using that method, a plane could travel from New York to London in about 90 minutes as opposed to the Concorde's three to four hours and a typical passenger jet's six to seven hours.
Even so, is it possible? Hermeus, an Atlanta-based startup with a hypersonic aircraft development mission, holds this view. It is now conducting tests on a new type of engine that it claims will eventually be able to travel at Mach 5. (over 3,000 mph). The engine was created by Hermeus for a small, unmanned hypersonic aircraft that the US Air Force is currently developing, but it can power a passenger airliner when scaled up.
Hermeus expects to have that passenger plane in the air for its first test flight before the decade is out, in 2029, but the company is already planning it out because its technology must be nearly totally constructed from scratch. It will be far smaller than both modern airplanes and the Concorde, which could carry about 100 people. "To help us size the aircraft, we basically built a business model for an airline," says AJ Piplica, CEO of Hermeus. "We focused on the business class and first class travelers, and then played around with some parameters such as speed and operating costs.
What came out of that was an aircraft with a 20-passenger cabin," he adds. That's not far from the capacity of a large business jet, which means there will be just one class."We expect it to be profitable at today's business class prices," says Piplica, with the caveat that it's hard to gauge how much people will be prepared to pay to fly five times faster, because "you can't really answer that question until there's a product out there and you have the real data."
Faster than ever
The plane's range will be around 4,000 nautical miles, which is sufficient for transatlantic flights like those from New York to Paris but insufficient for transpacific ones like those from Los Angeles to Tokyo, which would necessitate a layover. Due to noise restrictions, routes across land, like New York to LA, are out of the question. Breaking the sound barrier requires a huge boom, which is typically only possible over water. It helps to look at flight speed records to comprehend how risky the concept of a Mach 5 passenger airliner is. The NASA X-43A, an unmanned aircraft with a length of about 12 feet, set the record for the fastest engine-powered aircraft to ever fly at Mach 9.6 (about 6,800 mph) in 2004.