Concorde’s legacy reborn: The race for a hypersonic future
The Concorde, the last and one of only two large passenger jet aircraft in history, retired over twenty years ago. Many companies have expressed a desire to build an improved successor, but little has been accomplished so far. The situation might change with the Quarterhorse, a hypersonic passenger plane technology demonstrator.
Hypersonic vehicles are commonly associated with weapons. They are gliding or propulsion-driven objects designed to overcome modern, increasingly sophisticated air defense systems due to their high speeds.
This is due to their high speeds—on the order of Mach 5 and above—and maneuverability capabilities, which differentiate modern hypersonic weapons from, for instance, intercontinental ballistic missiles.
While these missiles descend on targets at very high speeds (over 12,430 mph), they move along predictable, calculable ballistic curves, making them easier to destroy.
That is why the world's greatest powers are developing hypersonic weapons. Due to the advancement of work and the declared features of the equipment being created, leaders are said to be China and Russia. The United States, with constructions like the AGM-183A ARRW, is closing the gap with them, and France is also developing its hypersonic missile, the ASN4G.
Hypersonic vehicles, in addition to being associated with innovative weapons, offer breakthrough potential in civil applications. One example is the development of an ultra-fast mode of transportation that significantly reduces travel time over long distances. Work on this has progressed beyond the conceptual and design phases.
Concorde and Tu-144
For years, the Concorde was a symbol of fast passenger transport. It was developed in the 1960s through the combined efforts of the French company Aérospatiale and the British BAE.
The Concorde reached a speed of Mach 2.04 (about 1,370 mph), ascended to 59,000 feet, carried up to 128 passengers, and allowed for flights over distances exceeding 4,350 miles, which was sufficient for regular transatlantic flights between Europe and the United States.
The Concorde was distinguished by its maximum speed and ability to maintain high flight speeds for extended periods. Because of this, even theoretically faster military aircraft, like the Tornado, could only accompany the Concorde for a short time, as flying at such high speeds quickly drained their fuel tanks.
Alongside the Concorde, passenger flights were also served by its eastern competitor, sometimes called the "Konkordski," the Russian Tu-144. However, high failure rates and operating costs led to their retirement from scheduled flights as early as the 1970s.
The Concorde continued to serve passenger flights until 2003. This type of aircraft was retired after an accident involving one of them, but the key reason was the very high costs, which made further operation unprofitable. The retirement of the Concorde means that, for over twenty years, mass passenger air transport has been served by subsonic machines.
Quarterhorse Aircraft
Although a successor to the Concorde has not yet been built, constructions are emerging to test technical solutions and verify ideas for developing a new hypersonic passenger aircraft.
According to its originator, Hermeus from Atlanta, the trip from Europe to New York will take no more than 90 minutes aboard their aircraft. The aircraft is supposed to be a groundbreaking construction that will allow for fast travel and change the nature of global passenger transportation by offering previously unattainable possibilities.
Will this actually be the case? The opportunity to say "check" is approaching quickly, as Hermeus has announced the completion of the hypersonic Quarterhorse aircraft's flying demonstrator.
The project of building the ultimate hypersonic passenger machine is being realized in stages, marked by the completion of successive experimental, unmanned constructions. The first of them, Quarterhorse Mk 0, had no flight capability and was created to test onboard installations on the ground.
The second prototype—completed in December 2024, the Quarterhorse Mk 1—is currently being tested on the ground but is expected to take flight in 2025. It will fly at subsonic speeds, primarily for take-off and landing tests. The plan is for another flying prototype, the Quarterhorse Mk 2, powered by the F100 engine known from the F-16 fighter jet, to reach supersonic speeds in 2025.
An aircraft with a ramjet engine
Only the Quarterhorse Mk 3, whose first flight is planned for 2026, will receive the ultimate Chimera II propulsion. It combines the F100 engine with a scramjet (a ramjet engine with a supersonic combustion chamber).
A hybrid propulsion system is necessary because the aircraft must be accelerated to high supersonic speeds to activate the ramjet. Hermeus anticipates that the Quarterhorse Mk 3 will reach Mach 5 speeds—around 3,730 mph—allowing it to be classified as a hypersonic machine.
Successors to the Concorde
Tests conducted on a series of unmanned aircraft are expected to contribute to developing a military hypersonic aircraft, Darkhorse, and subsequently, the ultimate passenger aircraft, Halcyon, which can carry up to 20 passengers. Hermeus anticipates that commercial flights of this construction will begin as soon as 2029.
Even if this optimistic schedule is maintained, Hermeus will not hold a monopoly. Though an attempt to build a supersonic passenger aircraft buried Aerion Corporation several years ago, similar machines are being developed by companies like Boom Technology. The Boom XB-1 demonstrator will fly in March 2024.
Exosonic is also developing a successor to the Concorde. Its large passenger machine is being considered a future platform for Air Force One. In November 2024, the Chinese company Lingkong Tianxing Technology also revealed its work on the supersonic passenger aircraft Cuantianhou.
