I've begun to prototype the rocket, and thanks to my friend Erica, I've learned that fins won't do much to stabilize the rocket in a low pressure environment. That being said, the two options of stabilizing the rocket are a computer-controlled nozzle or by spin-stabilizing the rocket. I've decided that a computer controlled nozzle on a solid rocket engine will be tricky, so for now I'm trying a spinning rocket first.

I 3D printed a engine housing that holds two rocket engines, both angled 5 degrees from each other. I'm hoping that this slight angle will be enough to impart spin on the rocket. The engine housing also has some holes for the igniter wires to go through, a center hole for the launch rod, and a couple places to place springs. The springs will be used to make electrical contact with the launch platform. I want to place the relay and battery inside the rocket, so that if one engine ignites first, the other one can ignite even after leaving the platform . I'm hoping they will both still light before leaving the launch rod though.

The body of the rocket is made of stacked toilet paper tubes. These are cheap, light, and by stacking them, I can take the rocket apart if need be.

After messing around with this for a few days, I 3D printed a nose cone and I also added vents for the ejection charges on the the rocket engines. The goal of the rocket is to test the spin stabilization, not recovery. There is no parachute, and I need to direct the charge outside of the rocket to avoid destroying the relay or causing a fire. The relay might break in the fall, but I'm willing to take that risk to accelerate the prototyping process.

Did a test launch today and the engines failed to ignite. I tested the wiring with a multimeter beforehand, so I believe the circuity was fine. I had some successful tests with overheated resistors beforehand as well. I think the issue probably lies in using two igniters with a single 9v battery. Not sure what the current required for these igniters was, so without being able to do the math, I just kinda winged it. I couldn't do tests with the Estes igniters because they don't give you extra igniters in the rocket engine packs. I will try to see if I can find the numbers I need to do the math, make my own igniters, or find a way to buy official igniters separately so I can do more tests before the next launch.