The results this guy got are… well, “meh.” But it’s a first stab at it. If he, or anybody, got the process nailed down, the potential exists for making proper star-grain solid propellant just the right size for gyrojet-style miniature rockets. An idea to improve on the gyrojet might be to make a star grain using a normal-ish solid propellant, and fill the empty volume with a high burn rate, high surface area propellant like nitrocellulose. On ignition you’d get a burst of high thrust, like the booster charge on an RPG, followed by a slower burning sustainer. For something like a gyrojet, that “slower burn” would still need to be pretty damn quick; ideally, you’d want the rocket to burn out within just a few feet. Better still, while still within the barrel. Not sure how good a printable resin-based propellant would be if filled with powdered nitrocellulose, but it might be worth some experimenting.
Dec 312021