New High‑Energy Drop‑In Fuel Clears First Rotating Detonation Engine Test

In July 2026, engineers at Venus Aerospace fired up a rotating detonation rocket engine (RDRE) with a brand‑new fuel from CycloKinetics. The fuel, branded CycloRP, is marketed as a “drop‑in” replacement for the classic RP‑1 and RP‑2 kerosene‑based propellants that have powered rockets for decades.

What makes CycloRP interesting isn’t just its chemistry; it was deliberately designed to be compatible with existing hardware. No engine redesign, no new injector – just pour it in, and the engine should run, or in this case, detonate, without a hitch. The test was backed by the U.S. Air Force Research Laboratory and the Department of War’s Office of the Under Secretary of War for Research and Engineering, adding a layer of official scrutiny.

The RDRE operates on a fundamentally different principle than traditional rocket combustors. Instead of a slow, steady burn, it harnesses a series of controlled detonation waves that travel around a circular chamber. Those rapid pressure spikes can theoretically extract more usable energy from each ounce of fuel, boosting specific impulse and overall efficiency.

During the first phase of testing, CycloRP not only ignited, it detonated cleanly and repeatedly. That’s a big deal because the extreme pressures and temperatures inside an RDRE can quickly expose weaknesses in a propellant’s formulation. The successful detonations suggest CycloRP can survive those hostile conditions while still delivering the energetic punch the engine needs.

“Fuel efficiency is a cornerstone of our propulsion roadmap,” said Sassie Duggleby, co‑founder and CEO of Venus Aerospace. “Seeing CycloRP perform as expected gives the Air Force and us confidence to keep exploring alternatives to legacy propellants.”

The next test phase, slated for early 2027, will shift focus from pure combustion to thermal management. Rocket engines generate staggering heat, so engineers often circulate fuel through passages that act like a heat sink before it reaches the combustion zone. CycloKinetics and Venus will compare how well CycloRP absorbs and dissipates heat against the traditional RP‑1 and RP‑2 fuels. If CycloRP can match or beat those benchmarks, it would truly earn the “drop‑in” badge.

Both companies have been collaborating since a June 2025 trial at Venus’s Houston facility. This expanded program builds on that foundation, aiming to deliver a comprehensive performance profile by early 2027. Should CycloRP pass the final round, it could open the door for U.S. launch providers to adopt a domestically produced, higher‑energy propellant without redesigning their engines.