there’s more than enough info on his site to try and recreate some of his experiments, but perhaps you should start here instead: How to Design, Build and Test Small Liquid-Fuel Rocket Engines.

A rocket stove offers a practical way to concentrate fire’s heat in one direction and reduce fuel consumption. Whether you need to purify water, cook food, or simply stay warm, this build is one ...

In fact, on July 24th, the HEXA rocket was officially certified as Open Hardware by the Open Source Hardware Association (OSHWA) — a first for a DIY rocket, as far as we can tell.