Estes Energetics and Utah State University will partner together to develop a hybrid rocket motor for the next generation of sample return missions. This system will incorporate several unique technologies that provide the performance and reliability needed for a sample return propulsion system, including a high-capability electric ignition system; an efficient, safe, and high-performance oxidizer; and 3D printed fuel grains.
The patented electric ignition system utilizes recently discovered unique properties of some 3D printed materials whereby electricity applied to the material carves an "arc-track" through the layered material. The associated Joule-heating pyrolyzes fuel, and as oxidizing flow is introduced, ignition spontaneously occurs. This property is being developed into a power-efficient system, that can reliably cold-start and restart hybrid rocket motors. The resulting system is radically simpler and allows for a large number of motor restarts without the complexity or danger of an ignition train containing energetic materials.
Novel Nytrox oxidizer has the volumetric efficiency of nitrous oxide without its decomposition dangers. It can be stored for long-term missions and has been demonstrated to have a specific impulse greater than 300 s.
3D printed fuel grains enable a large variation in geometry, that in turn enables optimization of the thrust profile when combined with the deep throttle capability of our hybrid. For sample return, the thrust can be optimized for a high launch thrust followed by an efficient cruise phase thrust. Multiple restart capability further optimizes the thrust profile.
Our additively manufactured hybrid motor technology is highly applicable to NASA sample return missions requiring reliable, restartable, controllable, and efficient propulsion systems. If developed successfully it will not only serve as a point solution for these “high gear ratio” applications, but also an ideation point or market stimulus to encourage a greater number of these missions once the technology has been proven successful and costs continue to fall as development is completed.
This hybrid motor technology solves weight and volume challenges in propulsion system while also improving control and restart capabilities. This includes satellite maneuvering, de-orbit propulsion, defense applications such as the upper stage of missile defense interceptors, and any applications where a traditionally energetic material fuel source poses safety issues.