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.
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...