By David Szondy
December 28, 2023
The RDRE fired for a record 251 seconds/NASA
NASA has pushed forward a revolutionary new rocket technology at its Marshall Space Flight Center in Huntsville, Alabama. Engineers at the facility fired the 3D-printed Rotating Detonation Rocket Engine (RDRE) for a record 251 seconds with 5,800 lb (2,631 kg) of thrust.
For over six decades, NASA has relied on chemical rockets to launch its vehicles into space. It works, but chemical rockets suffer from the fact that they’ve been operating in the neighborhood of their theoretical limit since 1942. This isn’t helped by the fact that most liquid rockets are essentially unchanged in their basic design since the days of the German V2s.
To squeeze a bit more performance out of rocket engines, NASA is looking at a fundamentally different design with the RDRE.
Instead of a combustion chamber where fuel and oxygen are fed in to burn at subsonic speed, in an RDRE these are introduced into a gap between two coaxial cylinders. When this mixture is ignited, they form a closely coupled reaction and shock wave. That wave travels inside the gap at supersonic speed, generating more heat and pressure.
If this burn can be sustained, it can produce a rocket thrust that is much more efficient. In fact, NASA says that the latest test firing was powerful enough and long enough that it could meet the requirements for a lander touchdown or deep space burn required for a mission to the Moon or Mars.
However, NASA stresses that the technology is far from mature and that test firings like this one are needed to scale up the combustor for different thrust classes. If this is successful, RDREs could find work in landers, upper stage boosters, and retropropulsion to land large payloads on the surface of Mars.
“The RDRE enables a huge leap in design efficiency,” said Marshall combustion devices 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.”
The video below recaps the test firing: