NASA has its eyes set on Mars, but the agency is still developing myriad technologies that we'll need for future space exploration. Among NASA's next-gen ideas is the Rotating Detonation Rocket Engine (RDRE), a project under the Game Changing Development Program. After first testing this new form of propulsion a year ago, NASA has now conducted an even longer RDRE test fire, moving this technology one step closer to reality.
A Rotating Detonation Rocket Engine is an alternative to traditional combustion-based engines. These engines use small explosions inside the circular annular channel using the same fuel and oxidizer mixture seen in standard rocket engines. The detonations are self-sustaining after ignition and travel around the channel continuously. Simulations have shown that rotating detonation engines could increase fuel efficiency by 25%.
NASA's 2022 test saw the prototype engine fire for almost one minute, producing 4,000 pounds-force (18 kN) of thrust. The new test at NASA's Marshall Space Flight Center moves this technology much closer to reality. The new 3D-printed engine has been scaled up to its full size, and it successfully fired for 251 seconds. That's about how long the engine would need to fire during a real mission.
NASA reports that the new engine managed more than 5,800-pound-force (26 kN) of thrust, a substantial increase over the last test. However, engineers at NASA’s Glenn Research Center still have a long way to go. NASA hopes to see much more thrust from future versions. It previously said it was aiming for 10,000-pound-force (44 kN) of thrust in the final design.
"The RDRE enables a huge leap in design efficiency," says NASA engineer Thomas Teasley. "It demonstrates we are closer to making lightweight propulsion systems that will allow us to send more mass and payload further into deep space, a critical component to NASA’s Moon to Mars vision."
Rotating Detonation has the potential to make rockets much more efficient, but they are less stable and harder to control compared to traditional rockets. They're also terrifically loud. The new test will help engineers better understand how to scale RD engines for different thrust classes, from landers to interplanetary transport. NASA has not announced plans for its next round of tests, but it only took a year to go from a few seconds to more than four minutes. That's impressive progress.
