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The United States Defense Advanced Research Projects Agency (DARPA) announced that Raytheon will develop a working rotating detonation engine demonstrator (RDE), which could let the “Gambit” program produce a more compact, higher efficiency propulsion system than conventional missile propulsion.

The “Gambit” program is an innovative engine development project that can potentially support future military weapons systems for multiple services. Raytheon explains that due to its compact size and efficient combustion, the engine offers an increase in range and speed compared to existing long-range weapons, enabling quick response to advanced threats.

RDE technology offers promising potential for propulsion and energy systems in the future, thanks to their high thermodynamic efficiencies and compact design.

According to Interesting Engineering, an RDE is a detonation wave that travels around a circular channel. Small holes or slits inject fuel and oxidizer into the channel, and then an igniter is used to initiate detonation in the fuel/oxidizer mixture. Once the engine is started, the detonations should become self-sustaining, and the combustion products then expand out of the channel and are pushed out by the incoming fuel and oxidizer.

RDEs have the potential to significantly save fuel costs, but they unfortunately suffer from instability and produce higher noise levels than other types of aerospace engines.

The “Gambit” program’s contract requires RTX to use iterative development of performance models anchored by real-world data from incremental system tests. This method helps to accelerate learning, resulting in more certain flight test outcomes, which saves both time and cost. In the future, the “Gambit” program may involve building hardware for conducting a flight weight-free-jet test.

Raytheon explains that with the contract, RTX became the first company to apply rotating detonation engine technology into an actual test system.