It is actually using a hollow cylinder of acrylic as the fuel, with gaseous oxygen as an oxidizer. We’re already quite familiar with solid rocket propellant, but this hybrid approach is much ...

Hybrid rocket engines offer perks from both worlds, with simple solid fuel and the ability to throttle down by regulating oxidizer flow. Naturally, [Integza] decided he should try and 3D print one.

challenges remain in the development and implementation of hybrid rocket propulsion systems. These include addressing low-frequency instability, managing the shift in oxidizer-to-fuel ratio during ...