Additive manufacturing drives RTX’s progress on rotating detonation engines

RTX engineers have achieved a key milestone in the development of rotating detonation engines (RDEs), a propulsion technology long theorized but rarely demonstrated at scale. Central to that progress is the application of additive manufacturing, which enabled the production of testable engine components with complex geometries that would be difficult or impossible to fabricate through conventional methods.

The successful test, conducted at the RTX Technology Research Center in Connecticut, marked a turning point for RDEs—a class of engines that operate without moving parts and promise higher thrust and fuel efficiency than traditional combustion systems. The technology has significant implications for military effectors such as high-speed missiles, where size, power, and range are critical factors.

RDEs generate thrust by sustaining a continuous detonation wave in a ring-shaped combustion chamber. To operate efficiently, they require precise fuel-air mixing and structural components that can withstand high pressures and temperatures while maintaining tight tolerances. Additive manufacturing made it possible to produce these intricate parts quickly, iterate on designs, and incorporate real-time test data into ongoing development cycles.

Steven Burd, Chief Engineer for Advanced Military Engines at Pratt & Whitney, said that engineering the fuel injection system was one of the main technical hurdles. “It’s an art form of finding something that gives you the conditions you want repeatedly,” he said. Without the design flexibility offered by additive manufacturing, the team would not have been able to refine the detonation chamber and injection geometry fast enough to meet performance benchmarks.

The initiative has progressed through a series of U.S. Air Force Research Laboratory contracts, with RTX leveraging its internal structure across business units. The RTX Technology Research Center led early research, while Pratt & Whitney is now maturing the engine system. Raytheon, which develops missile platforms, is positioned to integrate the engine into flight systems, accelerating the path from lab to battlefield.

Beata Maynard, Associate Director in Advanced Military Engines at Pratt & Whitney, confirmed that additive manufacturing will continue to be used not only for prototyping but also for eventual engine production. “We’re validating models with new data and using additive techniques to refine both design and build,” she said.

The compact, power-dense nature of RDEs could free up internal space in missile systems for more fuel, sensors, or payload, offering a tactical advantage. Despite the engineering complexity, RTX believes the propulsion architecture is now within reach.

“Our latest test results exceeded expectations,” said Chris Hugill, who leads Pratt & Whitney’s GATORWORKS development team. “They make a compelling case for further investment as we move toward full system ground testing and then vehicle flight test.”