The American firm Astrobotic has completed a sequence of firing trials for its rotating detonation rocket engine, named Chakram. These trials took place at NASA’s Marshall Space Flight Center in Huntsville, Alabama. During the testing campaign, two Chakram engine prototypes collectively underwent eight hot-fire runs. One of the prototypes sustained a continuous operational cycle lasting 300 seconds—the longest single firing duration recorded to date for rotating detonation rocket engines (RDREs). The total accumulated burn time across the entire testing program reached 470 seconds, with neither of the two prototypes sustaining any structural damage.
Rotating detonation engines represent an experimental technology that holds promise for powering future spacecraft set for lunar journeys and deep space exploration. Unlike conventional rocket engines that rely on deflagration (subsonic combustion), RDREs unleash rapid energy release via supersonic detonation waves that circulate within the engine casing. Astrobotic reports that this method offers a 15 percent boost in specific impulse, thereby enhancing engine efficiency, while also improving the thrust-to-weight ratio and enabling a more compact design.
The Chakram prototype was conceived and brought to fruition with support from two NASA Small Business Innovation Research awards, in addition to an ongoing Space Act Agreement with the Marshall center. In the recent tests, each of the two prototypes achieved a thrust output of 1,814 pounds of force, equivalent to approximately 17.8 kilonewtons. Bryant Avalos, the lead researcher for the Chakram program at Astrobotic, indicated that the engine surpassed expectations, demonstrating performance superior to preliminary predictions. He emphasized that achieving the 300-second continuous burn was a major milestone. According to him, such demonstrations confirm that RDRE technology is viable for a broad array of Astrobotic missions, ranging from propulsion systems on forthcoming lunar landers to orbital transport vehicles and other systems within cis-lunar space.
Astrobotic made history in 2024 by becoming the first private U.S. company to launch a craft toward the Moon; however, the Peregrine lander mission ultimately failed due to an issue with a valve. The company is now preparing for its subsequent mission targeting the Moon’s south pole, the very region where NASA intends to mine water ice from permanently shadowed craters in the future. This flight could materialize within the current year. Astrobotic believes that the successful firing tests of their detonation engine could pave the way for more cost-effective and efficient lunar endeavors. The company is committed to continuing the design, refinement, and testing of this engine.
Travis Wanzanski, the RDRE Program Manager at Astrobotic, highlighted that a small team operating under a modest budget managed to achieve this success, noting that the engine’s flawless initial operation speaks volumes about the team’s expertise. Other aerospace entities, such as Venus Aerospace, are also conducting their own RDRE evaluations. Last May, Venus Aerospace announced it had carried out the first flight test of a rotating detonation engine in the United States.
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