Astrobotic’s Rotating Detonation Rocket Engine Achieves Record 300-Second Burn, Unveiling Spiral Exhaust Flame

You don’t need to be a rocket scientist to marvel at the spiral exhaust flame produced by Astrobotic’s rotating detonation rocket engine (RDRE). The aerospace company’s latest innovation, named Chakram—after the ancient throwing weapon—has captured attention for its efficiency and performance.

The engine’s operation relies on supersonic detonation waves that travel in circular patterns around its outer edge. As Astrobotic explains in a video accompanying the announcement, the system uses multiple waves chasing each other to enable rapid and efficient combustion.

“You have these supersonic detonation waves that travel in circles around the outer part of this rocket engine. In fact, we didn’t add just one of these supersonic waves; we had three detonation waves chasing each other around the outside of this. That’s what allows for this very efficient, very rapid combustion to enable these high thrust applications.”

During testing at NASA’s Marshall Space Flight Center, the Chakram RDRE operated continuously for 470 seconds without damage. This included a single 300-second burn, believed to be a new record for RDRE technology. The visible result is a tightly wound spiral of shock diamonds—a phenomenon familiar to enthusiasts of military aircraft and space travel.

The shock diamonds form when supersonic exhaust pressure fails to match the surrounding atmosphere, creating compression and expansion waves. Bryant Avalos, Astrobotic’s principal investigator for the Chakram program, highlighted the engine’s performance:

“Chakram more than exceeded our expectations. With any cutting-edge technology like an RDRE, moving from design into testing, you’re always worried about unknown factors that could be critical to performance. But the engine performed even better than expected. The 300-second burn was the cherry on top. 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.”

The Chakram RDRE achieved more than 4,000 pounds of thrust in multiple tests, a remarkable feat given its compact size. Astrobotic plans to integrate the engine into its existing product lineup, which includes the Xogdor VTOL reusable rocket and two lunar landers. The company suggests that the engine’s efficient combustion could enhance payload capacity and mission speed.

The breakthrough underscores the growing potential of RDRE technology for future space exploration, particularly in lunar and cislunar missions.