NASA tests hybrid rocket motor to improve safe lunar landings

NASA tests hybrid rocket motor to improve safe lunar landings
by Clarence Oxford
Los Angeles CA (SPX) Apr 28, 2025

NASA's Artemis program will rely on human landing systems developed by SpaceX and Blue Origin to ferry astronauts between lunar orbit and the Moon's surface, paving the way for future crewed missions to Mars. During these critical landings and takeoffs, rocket plumes will disrupt the lunar surface, affecting the fragile regolith layer by creating craters and ejecting debris at high speeds.

To better predict these effects, a team at NASA's Marshall Space Flight Center in Huntsville, Alabama, has fired a 14-inch hybrid rocket motor more than 30 times. Developed by Utah State University using 3D printing technology, the hybrid motor burns a combination of solid fuel and gaseous oxygen, producing a powerful exhaust jet for testing.

"Artemis builds on what we learned from the Apollo missions to the Moon. NASA still has more to learn more about how the regolith and surface will be affected when a spacecraft much larger than the Apollo lunar excursion module lands, whether it's on the Moon for Artemis or Mars for future missions," said Manish Mehta, Human Landing System Plume and Aero Environments discipline lead engineer. "Firing a hybrid rocket motor into a simulated lunar regolith field in a vacuum chamber hasn't been achieved in decades. NASA will be able to take the data from the test and scale it up to correspond to flight conditions to help us better understand the physics, and anchor our data models, and ultimately make landing on the Moon safer for Artemis astronauts."

Out of the 30 firings conducted at Marshall's Component Development Area, 28 were performed under vacuum conditions and two at ambient pressure. These tests validate the ignition system before moving the motor to NASA's Langley Research Center in Hampton, Virginia, for the next phase.

Following the Marshall campaign, the motor will be transferred to NASA Langley, where engineers will conduct further tests firing into a simulated lunar regolith known as Black Point-1, inside the center's 60-foot vacuum sphere. By igniting the motor from different heights, teams will measure the crater dimensions and analyze the trajectories and velocities of the displaced regolith particles.

"We're bringing back the capability to characterize the effects of rocket engines interacting with the lunar surface through ground testing in a large vacuum chamber - last done in this facility for the Apollo and Viking programs. The landers going to the Moon through Artemis are much larger and more powerful, so we need new data to understand the complex physics of landing and ascent," said Ashley Korzun, principal investigator for the plume-surface interaction tests at NASA Langley.

"We'll use the hybrid motor in the second phase of testing to capture data with conditions closely simulating those from a real rocket engine. Our research will reduce risk to the crew, lander, payloads, and surface assets."