The hypersonic technology it continues to advance as fast as its name suggests, in an arms race that is powerfully reminiscent of the one that took place during the Cold War. While China and Russia successfully test their respective missiles capable of flying at more than five times the speed of sound (i.e. more than 6,000 km/h), The US Air Force has just awarded the first contract for its plan to develop an hypersonic aircraft unmanned and reusable combat.
while propping up his new network of satellites designed to deal with Chinese and Russian hypersonic threats and perform the tests ARRW, the first hypersonic missile successfully launched from an aircraft, the Pentagon wants to take the next step. And that is the objective of Project Mayhem (Project Chaos in Spanish), a secret program with which the US intends to overtake rival powers with an autonomous aircraft and markedly cheaper and more versatile than hypersonic missiles.
To do this, the Pentagon has trusted the manufacturer Leidos to develop an experimental design capable of demonstrating its ability to transport different types of payloads and carry out all kinds of intelligence, surveillance and reconnaissance missions. Everything seemed to indicate that the chosen one would finally be the Lockheed Martin SR-72 which, in addition to its cameo in the latest Top Gun moviestill must face some technological challenges.
However, the contract signed by the Pentagon with Leidos seems to reject this option and bet on a single engine. scramjet to reach speeds above 6,000 km/h. In any case, there may be more than one project running in parallel within Mayhem and the SR-72 can still put up a hell of a fight.
mayhem takes shape
The Air Force Research Laboratory (AFRL) has been in charge of closing a “single award, indefinite delivery/indefinite quantity” agreement, with a maximum limit of 313 million euros for the formally called Pproject Attack Hypersonic and multimission ISR.
[Así es HAWC, el misil hipersónico que EEUU prueba en secreto para no enfadar a Rusia]
“This program focuses on the delivery of a hypersonic system capable of performing multiple missions with a standardized payload interface, providing a significant technological advance and future capability,” the Pentagon contracting journal reports. “The work will be conducted at Wright-Patterson Air Force Base, Ohio, and other possible test locations to be determined, and it is expected to be finished by October 15, 2028“.
As confirmed by Reads in a press release, a System Requirements Review (SSR) will be conducted first, followed by a Concept Design Review (CoDR) using digital engineering. But what is more important is the confirmation of the type of engine that will propel the aircraft: “The Mayhem system will use a motor scramjet to generate pushpropelling the vehicle over long distances at speeds in excess of Mach 5″.
Ryan Leo, Mayhem Program Director, uses the same statement to boast of the “team assembled by Leidos, who combine exceptional experience with innovation. We are working with the best solution providers in the country in hypersonic vehicle technologies and propulsion. We are proud to contribute to this important national security mission“.
The image shared by the company, which is nothing more than an illustration prior to the final design, shows an unmanned hypersonic aerial vehicle with a single engine. The fuselage is long and with the characteristic curved lines of hypersonic projectiles, in addition to a hang glider configuration with a vertical tail.
[Un misil hipersónico ruso se habría estrellado por accidente en su territorio]
Regardless of how it evolves in the next six years, what it has to meet is the goal set by the Pentagon in 2021: “carry payloads with five times the mass and twice the range than current technological capability systems.” Those payloads are described as “area effect” and “large unit” weapons for attack missions, and some type of “sensitive” device to accomplish their ISR missions ( intelligence, surveillance and reconnaissance initials).
A very special engine
The Pentagon wants the result of Project Mayhem to be able to take off with its own means – lacking a mother platform – and to be reusable – discarding the rocket system. The only alternative that seemed possible was to use some sort of hybrid engine between that of a traditional aircraft for the first stages of the flight and a scramjet It starts running when it has reached a certain speed.
“This type of engine could revolutionize air travel and defense”, according to Chris Combs, a specialist in hypersonic and aerospace engineering at the University of Texas at San Antonio. The scheme would employ a conventional jet engine to take off and accelerate to about 3 times the speed of sound before transitioning to a scramjet capable of propelling the aircraft beyond 5 times the speed of sound. A challenge of aerospace engineering that moves in a very complex field and for which there is no known solution.
The compression system of a traditional jet turbine—like that of any aircraft today—impedes airflow by design. It can be seen with the naked eye in the large fan that the aircraft engines have in front. But, for his part, a scramjet it needs unobstructed airflow to function. An engine that meets both needs would have to merge both contradictory designs.
This kind of engines technically known as multiple cycle, are being a very important technological research area. The manufacturer Rolls-Royce is working on it for use in a space launch craft and DARPA is doing the same with the AFRE Program (Advanced Full Range Engine, in Spanish), as indicated Air Force Technology. It is not yet clear how Leidos will solve these problems if it goes with a single scramjet engine, information that will continue to come as development progresses.
Another of the challenges that those in charge of Project Mayhem will have to face is the heat, since the entire aircraft must be prepared to withstand high temperatures due to friction. “Going at more than 5 times the speed of sound generates extreme levels of heat, driving the need for innovative materials, sensors, and electronics to withstand such speeds throughout their journey,” Dave Berganini said at the time. Vice President of Hypersonic and Attack Systems at Lockheed Martin.