From New York to Paris in less than an hour? A startup builds an airplane that could make it happen

Hermeus Quarterhorse

A few days ago, NASA presented its supersonic X-59 aircraft, developed in collaboration with the aerospace giant Lockheed Martin. In a video, the aircraft was shown leaving a hangar to undergo ground testing.

The era of supersonic flights seems to return, after the era of the Concorde or the Tupolev 144 that were born to revolutionize aviation, and stopped crossing the skies of the world at the beginning of this century.

Taking up that tradition, a young startup in the United States has announced that next year it will put a new supersonic plane into the air that could fly from New York to Paris in just one hour. Supersonic flights could be back this decade (Hermeus)

This is Hermeus Quarterhorse who intends to exceed Mach 1, which is the speed at which sound travels through the air: that is, 340 meters per second or 1,235 kilometers per hour. But at Mach 5.5, that is, almost 6,800 kilometers per hour, a speed that ceases to be supersonic to become hypersonic.

Last week, the Atlanta-based company announced it had received a $30 million award from the US Air Force to fund testing of the innovative aircraft.

Like the Greek god Hermes, who had wings on his feet, this Hermeus is designed to travel at extreme speeds on Earth. That makes it the fastest reusable plane on the planet, so a flight from New York to London would take less than 60 minutes. The first flight of the aircraft will be next year (Hermeus)

Quarterhorse performs a series of tests to subject materials and equipment to high-velocity conditions. With the contract that Hermeus won for 30 million dollars from the US Air Force, the company seeks to build and fly three versions of the plane.

The first flight is scheduled for 2024 and the final investment could be around 100 million dollars, according to calculations by the entrepreneurial company itself.

Based on this business plan, Hermeus raised 119 million dollars in 2022, which today has been revalued to reach 400 million in that currency. In addition to its Quarterhorse model, Hermeus plans to launch the 20-passenger Halcyon airliner and another aircraft called the Darkhorse, which Hermeus hopes to begin flight testing in 2026, as a long-range attack and surveillance vehicle. Engineers work on an innovative supersonic engine (Hermeus)

According to the company, the speed will come from a unique engine configuration, a turbine-based combined cycle (TBCC) propulsion system.

Such systems use a standard jet engine for launch and landing and to generate enough airspeed to feed air to a second turbine, known as a ramjet or scramjet, which produces more power but requires high-velocity airflow to blaze up. The difficulty is managing the transition between the turbines and achieving the necessary aerodynamics.

Hermeus is off to a good start. In nine months he designed, built and tested his engine, which is based on the GE J85 turbojet, and has two advantages when it comes to testing. Technical characteristics of the new aircraft (Hermeus)

The Quarterhorse will fly autonomously, so the development team will be able to fly prototypes and learn from them without risking the lives of the pilots. Right now, it plans to test a small-scale version in 2024, a mid-size freighter version in 2025, and a larger commercial passenger version in 2029.

The other advantage is, of course, government money. “While this partnership with the US Air Force underscores DoD interest in hypersonic aircraft, when combined with Hermeus’ partnership with NASA announced in February 2021, it is clear that both commercial and defense applications exist. what we are building for,” said AJ Piplica, CEO of Hermeus.

Hermeus’ goal of having commercial aircraft in service by the mid-2030s is an incredibly difficult task, according to aviation industry experts. “The challenge is not reaching hypersonic speeds: missiles and space vehicles do it regularly. The difficulty is building something that can withstand those speeds and stresses and that is reusable,” said Luca Maddalena, a hypersonics researcher at the University of Texas at Arlington.The US Congress supported some 70 hypersonic programs in 2023 (Hermeus)

Reality indicates that air friction creates progressively more heat as the aircraft accelerates. To accommodate, the SR-71 Blackbird spy plane, which set the record for the fastest air-breathing manned aircraft at Mach 3.3 in 1976, had titanium alloy wing sections that were corrugated to allow them to expand as the air moved. casing got hot.

But as speeds increase above Mach 5, the heat begins to cause chemical reactions in the air around the vehicle. Oxygen and nitrogen split into individual atoms and can react with the airframe. “The aircraft is no longer flying in the air around it on the runway. It is a soup of different gases and it will most likely be different at each point in the vehicle due to variations in temperature and pressure,” Maddalena said, since at higher speeds some of the gas can turn into plasma.

Congress gave the Pentagon $5.8 billion in fiscal year 2023 to support some 70 hypersonic programs, up from less than $500 million in 2016. That shows the US government’s keen interest in developing this cutting-edge technology and making faster and safer flights.