In high school, my friends and I had the idea to make a rocket-powered jump-kit (from the videogame Titanfall 2). This was the original proof of concept project to see if our small budget could scrap something together that would be self-contained, safe enough, and with enough thrust to make a plausible wall-running rocket-pack. While the optimistic and sci-fi part of the project never came to fruition (mostly due to budget constraints), we did create and test a small scale DeLaval nozzle style rocket engine using hydrogen and oxygen gas for the fuel and oxidzer, which we generated using electrolysis. It never produced much thrust due to limitations with gas pressure and not enough generation of gas, but the experience taught us a lot about a wide range of skills and fields, like physics, manufacturing, electronics and control systems, and why the professionals use actual rocket fuel instead of hydrogen gas.