New high-energy drop-in fuel clears first rotating detonation rocket engine test

CycloKinetics is testing its alternative rocket fuel with Venus Aerospace in a rotating detonation rocket engine (RDRE). The program will examine whether CycloRP can replace conventional RP-1 and RP-2 propellants. CycloRP aims to work with existing engines without requiring hardware modifications. CycloKinetics designed the fuel for higher energy density and cleaner combustion. The testing has support from the U.S. Air Force Research Laboratory and the Department of War’s Office of the Under Secretary of War for Research and Engineering. Results from the program could offer a closer look at how alternative propellants perform inside advanced rocket hardware. RDRE puts fuel to test The first testing phase concluded in July 2026. Engineers evaluated how CycloRP behaved during combustion inside Venus Aerospace’s RDRE. The tests confirmed that CycloRP could successfully detonate inside the engine. That result is important because an RDRE uses controlled detonation waves instead of conventional combustion. The approach could improve propulsion efficiency by extracting more useful energy from the combustion process. It also creates demanding conditions for any fuel entering the combustion chamber. CycloRP therefore has to perform reliably under extreme pressure and temperature conditions. Successful detonation provides an early indication that the fuel can operate within the unusual environment created by an RDRE. Sassie Duggleby, co-founder and CEO of Venus Aerospace, said efficient fuel remains an important part of advancing the company’s propulsion technology. She also pointed to the testing as an opportunity for the Air Force and CycloKinetics to evaluate the fuel against established propellants. Venus has previously described its RDRE as flight-proven, giving CycloRP a test platform tied to an emerging propulsion architecture rather than a conventional laboratory setup. Cooling brings another challenge The second phase will examine CycloRP’s cooling performance. Rocket engines produce enormous amounts of heat, making thermal management a major engineering challenge. Engineers can circulate fuel through engine components before combustion. The fuel absorbs heat during that process, helping control temperatures before reaching the combustion chamber. CycloKinetics and Venus will compare CycloRP with RP-1 and RP-2 during this part of the program. The results should show whether CycloRP can provide comparable cooling performance while serving as the engine’s primary propellant. That test could prove just as important as combustion performance. A drop-in fuel must meet multiple requirements if operators want to use it without redesigning existing propulsion systems. The two companies previously conducted testing together at Venus Aerospace’s Houston facility in June 2025. The current program expands that relationship with additional combustion and thermal evaluations. Mukund Karanjikar, CEO and founder of CycloKinetics, said the company designed CycloRP as a direct replacement for conventional rocket propellants. He also highlighted domestic production as a potential advantage for future U.S. propulsion programs. A fuel that fits existing engine architectures could reduce the engineering work required to introduce a new propellant. It could also give propulsion developers another option as they explore higher-performance engine designs. The companies expect the combined testing to produce a fuller technical assessment in early 2027. CycloKinetics and Venus Aerospace plan to share additional results after the final testing concludes.Get the latest in engineering, tech, space & science - delivered daily to your inbox.Aamir is a seasoned tech journalist with experience at Exhibit Magazine, Republic World, and PR Newswire. With a deep love for all things tech and science, he has spent years decoding the latest innovations and exploring how they shape industries, lifestyles, and the future of humanity.