U.S. Air Force Tests Rotating Detonation Engine to Enable Faster Lower-Cost Mass-Produced Missiles.

The U.S. Air Force is preparing a flight demonstration of rotating detonation propulsion for future high-speed missiles designed for larger-scale production. The technology could enable longer-range air-to-surface and air-to-air weapons while reducing propulsion volume and supporting higher production rates.

The Air Force Research Laboratory plans to mature the Rotating Detonation Rocket Engine-Combined Cycle from Technology Readiness Level 3 to TRL 6 and integrate it into a ground-launched flight demonstrator initially accelerated by a sounding rocket. Developed for the High-Speed Affordable Mass Munitions concept, the propulsion architecture is intended to combine high-speed flight with a compact engine that could free internal volume for additional fuel or payload, with potential applications ranging from stand-off strike weapons to long-range air-to-air missiles.

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Notional air-to-air and air-to-ground weapons illustrating potential military applications of rotating detonation engine technology. (Image source: ARCTOS)

The program focuses on a Rotating Detonation Rocket Engine-Combined Cycle, or RDRE-CC. The technology uses continuous detonation waves inside the combustion chamber to generate high levels of thrust within a compact volume. For the U.S. Air Force, the purpose is therefore not simply to fly a new engine. The RDRE-CC is being assessed for the High-Speed Affordable Mass Munitions concept, or HAMM, which is intended to explore high-speed weapons that are affordable enough to be produced and employed in larger quantities. AFRL has already identified several possible applications for the broader RDE family, including high-speed air-to-surface weapons, long-range air-to-air missiles and surface-launched systems.

According to the solicitation published by the Air Force Research Laboratory on October 1, 2026 under the HERMES program, the objective is to mature the technology from Technology Readiness Level 3 to TRL 6. This would move the RDRE-CC beyond preliminary technology testing toward demonstration in an environment representative of operational conditions. The program is expected to last between 36 and 48 months. It includes engine development, several test campaigns, and integration onto a vehicle launched from the ground and initially accelerated by a sounding rocket before the propulsion system under evaluation is activated.

The main interest of rotating detonation propulsion lies in the way it converts propellant energy into thrust. In a conventional rocket engine, combustion progresses relatively continuously inside the chamber. In an RDRE, one or more detonation waves circulate at very high speed around an annular chamber. According to AFRL, these waves can exceed 2 kilometers per second. This process can produce high combustion pressure in a more compact architecture, which is particularly relevant for missile design, where available internal volume must be divided between propulsion, fuel, warhead, electronics, and guidance systems.

On an air-to-surface weapon, reduced propulsion volume could be used to carry more fuel and increase range without substantially enlarging the missile, or to maintain similar range in a more compact design. For a long-range air-to-air missile, AFRL has also examined whether RDE propulsion could extend reach while remaining within dimensions compatible with existing aircraft. This is particularly relevant for fighters such as the F-35A and F-22, whose internal weapons bays impose strict dimensional limits, as well as for the F-15EX, which is designed to carry larger missile loads externally. AFRL has specifically highlighted the possibility that a smaller propulsion section could free additional volume for fuel or payload.

The U.S. Air Force Research Laboratory conducts testing of a rotating detonation rocket engine as it evaluates the technology for future propulsion applications. (Video source: U.S. Air Force)

The U.S. Air Force is not moving directly toward an operational weapon. The program first calls for validation of the engine itself, followed by tests of the complete propulsion system in airflow conditions representative of flight, before integration onto the experimental vehicle. Direct-connect testing allows engineers to study propulsion performance under controlled conditions, while freejet testing more closely reproduces the aerodynamic environment encountered in flight. The final demonstration is intended to determine whether the engine can continue operating when the vehicle is actually traveling at high speed.

Industrial considerations are as important as maximum performance. HAMM is not simply a program to achieve additional speed. The concept is intended to combine high-speed flight with a weapon that can be stored, manufactured at high rates, and procured in larger numbers. That approach is comparable in some respects to the logic behind the U.S. Air Force Extended Range Attack Munition, or ERAM, a long-range air-launched cruise missile intended to provide a lower-cost precision strike capability that can be produced rapidly in quantity. ERAM and HAMM are separate programs, but both reflect the same broader concern: increasing the number of stand-off weapons available without assigning every mission to complex and expensive missiles. The U.S. Air Force conducted a live-warhead ERAM test in January 2026.

For combat operations, RDRE-CC propulsion could therefore apply to several weapon categories. On an air-to-surface missile, it could support stand-off strikes against radars, air-defense systems, military infrastructure, or other time-sensitive targets. On an air-to-air missile, the operational effect would be different: additional range or greater retained energy during the terminal phase, while remaining within a form factor compatible with existing aircraft. AFRL has explicitly presented RDE technology as a possible means of improving range, payload, speed, and the number of weapons an aircraft can carry. The current solicitation, however, provides no final speed, range, warhead specification or intended launch aircraft. It therefore does not support identifying HAMM as a specific future missile or describing it as a hypersonic weapon at this stage.

The effort also fits a broader change in U.S. force planning, where available missile quantities are becoming nearly as important as the performance of individual weapons. A conflict against an opponent operating numerous air-defense systems and dispersed bases could require large numbers of air-to-air and air-to-surface weapons during its opening phases. A more compact propulsion system that is also easier to manufacture could therefore be relevant both to future stand-off strike weapons and to air-to-air missiles beyond the AIM-120 AMRAAM generation. RDRE-CC remains experimental, but the planned flight demonstration is intended to determine whether rotating detonation propulsion can move beyond laboratory research and become a practical option for future U.S. weapons produced at scale.

Written By Erwan Halna du Fretay - Defense Analyst, Army Recognition Group
Erwan Halna du Fretay holds a Master’s degree in International Relations and has experience studying conflicts and global arms transfers. His research interests include security and strategic studies, particularly the dynamics of the defense industry, the evolution of military technologies, and the strategic transformation of armed forces.