Astrobotic’s Chakram Rotating Detonation Engine Achieves Record 300-Second Hot-Fire Test

Astrobotic, a Pittsburgh-based space firm, completed eight hot-fire trials of its Chakram rotating detonation rocket engine (RDRE) at NASA’s Marshall Space Flight Center in Huntsville, Alabama. Two prototypes logged more than 470 seconds of firing, including a continuous 300-second burn—the longest sustained RDRE operation reported. Each engine produced over 4,000 pounds (?1,800 kg) of thrust, reached a stable thermal steady-state, and showed no visible damage.

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Conventional liquid-propellant rockets burn a flame in a combustion chamber. RDREs instead compress and heat propellant with a supersonic shock wave, generating a detonation that travels around a ring-shaped chamber. This mode can raise specific impulse by roughly 10–15 percent and improve thrust-to-weight ratios, enabling smaller, lighter engines suited for lunar and deep-space missions.

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Astrobotic’s principal investigator Bryant Avalos said the test “more than exceeded our expectations” and called the 300-second burn “the cherry on top.” He noted that the result demonstrates how RDREs could power future lunar landers and in-space transfer vehicles. The campaign was funded by two NASA Small Business Innovation Research awards and a Space Act Agreement with Marshall, showing support.

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Although the 300-second burn sets a record, the engines are not yet flight-ready. At roughly 4,000 pounds of thrust each, Chakram’s output is modest compared with SpaceX’s Falcon Heavy, which delivers over five million pounds from 27 engines. Astrobotic acknowledges that hot-fire tests, throttling studies, and regenerative-cooling improvements are needed before integration onto a launch vehicle such as Griffin lunar lander slated for a Falcon Heavy launch by July.

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• “Chakram more than exceeded our expectations… the engine performed even better than expected,” — Bryant Avalos, Principal Investigator, Astrobotic

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• “The 300-second burn was the cherry on top.” — Bryant Avalos, Astrobotic press release

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• “Seeing the engine perform flawlessly on its first attempt is a testament to their acumen, ingenuity, and scrappiness.” — Travis Vazansky, RDRE Program Manager, Astrobotic

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• “Demonstrations like this show how RDRE technology could support a wide range of Astrobotic missions, from propulsion on future lunar landers to in-space orbital transfer vehicles, and other capabilities that will help expand operations throughout cislunar space,” — Bryant Avalos, Astrobotic statement

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Astrobotic plans to use the test data to refine throttling, regenerative cooling, and mass reduction as it moves toward flight-ready hardware. The company’s upcoming lunar south-pole mission, targeted for launch later this year, could benefit from Chakram’s efficiency. RDRE efforts include Venus Aerospace’s U.S. flight test in May 2025 and JAXA’s six-second space-based test in 2021, indicating industry momentum toward rotating-detonation propulsion for cislunar and deep-space applications.

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