He had an a great idea – is it possible to 3D print a solid fuelled rocket, (video, embedded below) specifically can you 3D print the rocket grain itself? By using the resin as a fuel and mixing ...

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.

See how Relativity's Terran 1 rocket got from the 3D printer to the launch pad in these highlights. Credit: Relativity Space ...