When it came to choosing a final year project I wanted to work on rocket propulsion; I thought this would be exciting and represented the
biggest hole in the aims of Starchaser that I was then involved with. I actually settled on hybrids by chance as I thought they would
be easier to handle in a university setting and more likely to get permission. And indeed I was right, though course mate and future
work colleague Anthony Haynes did successfully start a bi-liquid project that year, testing occurred after the degree under the auspices of Starchaser.
I had little idea how to design the engine and started with the hybrid section of Rocket Propulsion Elements. I didn't at first properly grasp the fuel regression constants and was looking for a degree of theoretical certainty that doesn't actually exist! This was complicated further by an excellent example of a similar project that came from pre-word processor days and was as a result inadvertently missing the Gox term in the regression rate equations.
The hardware itself was made out of a big lump of brass that was apparently an old hydraulic fitting. It had variously clay, brass and phenolic nozzles, but given the poor gaseous oxygen supply it never ran properly and never produced any measurable thrust. But, one has to start somewhere, it was a good final year project and was a fun start. I don't seem to have any pi cutes of it and will have to get round to capturing some from the testing video, if it still plays...