Astrobotic put its Chakram rotating detonation rocket engine (RDRE) through its paces for the first time.

During the tests, which took place at NASA’s Marshall Space Flight Center (MSFC) in Huntsville, Alabama, two Chakram engine prototypes completed a total of eight hot-fire tests.

According to the space startup, this included a record-breaking 300-second burn—the longest duration hot firing of any RDRE engine yet. Neither of the engines was damaged during the 470 seconds of hot firing accumulated during the tests.

RDREs are an experimental propulsion technology that have the potential to one day power highly efficient spacecraft to the Moon and further into deep space.

Chakram’s highly efficient detonation process

Unlike conventional rocket engines, which harness deflargration, RDREs leverage the rapid energy release of supersonic detonation waves that rotate around an engine’s circular body.

According to Astrobotic, this detonation process leads to an increase in specific impulse, or engine efficiency, of 15 percent. It also allows for an increased thrust-to-weight ratio, allowing for a more compact design.

During the recent hot-fire tests, Astrobotic’s Chakram engines each produced 4,000 pounds of thrust (1,800 kilograms), for a combined 470 seconds of total runtime. You can watch footage from the test in the video below.

Astrobotic’s prototype engine, Chakram, was designed and developed with the support of two NASA Small Business Innovation Research awards, as well as a Space Act Agreement with NASA Marshall.

“Chakram more than exceeded our expectations… the engine performed even better than expected,” Bryant Avalos, Astrobotic’s Principal Investigator for the Chakram program, explained in a press statement. “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.”

Astrobotic’s lunar ambitions

In 2024, Astrobotic became the first US private company to launch a lander to the Moon. Unfortunately, the firm’s Peregrine lander experienced a valve problem during the mission, leading to a failed lunar landing.

Now, Astrobotic is working on a follow-up mission that will send a lander to the lunar south pole, where NASA aims to eventually harvest water ice from the Moon’s permanently shadowed craters. Astrobotic’s lunar south pole mission could launch later this year.

Astrobotic believes its RDRE hot-fire test success could help pave the way for more efficient, lower-cost lunar missions. The company will now continue to design, develop, and test its engine.

“This was pulled off by a small group working on a modest budget,” Travis Vazansky, Astrobotic’s RDRE program manager, said in the firm’s statement. “Seeing the engine perform flawlessly on its first attempt is a testament to their acumen, ingenuity, and scrappiness.”

Other companies, such as Venus Aerospace, are also working on their own RDRE testing campaigns. In May last year, Venus claimed it made history by completing the first-ever flight test of an RDRE in the US. The firm aims to unlock a new era of hypersonic aviation.