China Claims Breakthrough In Hypersonic Engine Tech That Was Originally A US Concept Nearly 7 Decades Ago

In 1958, American scientists sparked a bold vision for a propulsion system: the Oblique Detonation Engine (ODE), a hypersonic engine that could, theoretically, travel at unprecedented speeds without moving parts. Initially funded by the U.S. Air Force and researched at the University of Michigan, the concept seemed too ambitious for its time. Decades passed with minimal progress until now.

Earlier this month, a peer-reviewed article in the Journal of Aerospace Power detailed a breakthrough ground test conducted by researchers from China Academy of Launch Vehicle Technology (CALT) and Northwestern Polytechnical University. In a first-of-its-kind demonstration, they ignited a sustained detonation using RP-3 aviation kerosene, a conventional jet fuel, within an ODE chamber at simulated flight conditions of Mach 8 and 30 kilometers altitude.

This is a significant leap because most hypersonic propulsion experiments traditionally rely on hydrogen fuel, which is far more volatile and less practical for military or commercial use. Achieving stable combustion with regular jet fuel under such extreme conditions marks a turning point in ODE viability.

“The findings prove the technical feasibility of internal-injection liquid-fuelled oblique detonation engines,” wrote lead researcher Yang Yang.

According to the study, stable detonation waves were maintained for 2.2 seconds—a record-setting duration compared to past Chinese experiments, such as a 50-millisecond explosion in December 2024. That earlier result was largely dismissed as academic. This new test is 40 times longer and has real-world implications.

ODEs belong to a class of wave combustors, described by NASA Ames as engines that “utilize oblique shock or detonation waves to rapidly mix, ignite, and combust the air-fuel mixture in thin zones.” This allows for shorter, lighter engines with less cooling required and higher operational Mach limits than conventional scramjets.

Unlike typical propulsion systems, ODEs merge combustion and shock waves in a fixed chamber. There are no moving parts, which simplifies design while theoretically enabling sustained flight speeds between Mach 6 and Mach 16, as hypothesized by NASA in 1978.

For this test, Chinese scientists used a central fuel injector with micro-sized nozzles to spray RP-3 into a supersonic airstream. A 20-degree wedge with two small bumps triggered the detonation. Through optical windows, blue-white detonation fronts and yellow afterburning zones confirmed partial fuel mixing and powerful combustion. Simulations showed a post-detonation pressure spike to 272 kPa, over ten times the initial pressure.

Despite the breakthrough, limitations remain. Only 39% of the combustion channel was filled with fuel, leaving much of the airflow lean. Wave stability also fluctuated due to inconsistent exhaust pressures. The team suggested modifying the injector and extending mixing zones to improve performance.

Still, experts believe military applications could arrive well before civilian ones. While an ODE-powered hypersonic jet between Shanghai and San Francisco may be years away, short-term uses could include advanced hypersonic weapons or aircraft systems.

This isn’t the first time China has successfully revived shelved American ideas. The ‘dream shell’ rail gun projectile, originally conceptualized by the U.S. Navy in 2012 and abandoned by 2021, has reportedly been realized by Chinese researchers. Similarly, thorium reactor technology, another U.S. Cold War-era invention, has recently been improved by Chinese scientists for real-time fuel refueling.

China’s progress with the ODE underscores its growing dominance in hypersonic technology, following the successful deployment of systems like the DF-17, YJ-21, and DF-27. It also highlights the irony of Beijing advancing technologies once pioneered and later neglected by Washington.

As U.S. programs still grapple with stabilizing detonation and managing extreme heat, this Chinese breakthrough could influence the future of aerospace propulsion and possibly tilt the strategic balance.

In the words of NASA, engines like the ODE offer “shorter and lighter engines, requiring less cooling and operating at higher Mach numbers.”