Explosions could be a more practical means of transportation.
NASA’s next-generation ideas include the Rotating Detonation Rocket Engine (RDRE), a project under the Game Changing Development Program. NASA first tested this new form of propulsion a year ago, and now it has conducted an even longer RDRE test fire, bringing this technology one step closer to reality. NASA has its sights set on Mars, but the agency is still developing a plethora of technologies that we will need for future space exploration.
The Rotating Detonation Rocket Engine is a substitute for conventional combustion-based engines that use the same fuel and oxidizer mixture as standard rocket engines to create small explosions inside the circular annular channel. After ignition, the detonations travel around the channel continuously and are self-sustaining. Based on simulations, it has been estimated that fuel efficiency could be increased by 25% with rotating detonation engines.
The new test at NASA’s Marshall Space Flight Center brings 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, which is about how long the engine would need to fire during a real mission. NASA’s 2022 test saw the prototype engine fire for almost one minute, producing 4,000 pounds-force (18 kN) of thrust.
Although engineers at NASA’s Glenn Research Center still have a long way to go, they report that the new engine managed more than 5,800-pound-force (26 kN) of thrust, a significant increase over the previous test. NASA hopes to see much more thrust from future versions; previously, it stated that it was aiming for 10,000-pound-force (44 kN) of thrust in the final design.
“It shows we are closer to making lightweight propulsion systems that will allow us to send more mass and payload farther into deep space, a crucial component of NASA’s Moon to Mars vision,” NASA engineer Thomas Teasley said of the RDRE. “It enables a huge leap in design efficiency.”
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 is impressive progress. Rotating Detonation has the potential to make rockets much more efficient. However, compared to traditional rockets, they are less stable, harder to control, and incredibly loud.