The most important stage of building a rocket engine is testing. First flow testing the injectors, then the fun can begin. Its time to do an injector plate hot test, this is basically removing the nozzle and doing an “open” burn to see that everything is working as intended, most importantly that the chamber can handle the extreme temperatures produced by these reactions. The temperatures in Epoch 1 were expected to top 5000 degrees, that’s more than hot enough to melt the majority of structural metals. This is why we went with a large piece of aluminum for our chamber, it is capable of radiating the heat away without melting, to a point of course.
Now it gets scary, putting the nozzle on. All we can do is stand back and hope our beautiful and very expensive rocket preforms as it is designed to, and not turn into a glorified pipe bomb. Sitting behind a tree stump and few rocks as a makeshift blast shield, double checking gauges, checking that injectors are all free of clogs, I have to say it was a very tense moment. Would our work be rewarded or would the rocket gods laugh in our faces? A lot to think about when prepping to fire an amateur build Bipropellent rocket engine.
As the countdown goes it only gets more stressful, at 8 the pit in my stomach turns into a dense knot, at 5 I can barely stand to watch. At 2 the oxygen flow starts, its already deafening as over 100 psi oxygen gas surges through the injector manifold. T minus zero, the fuel valve is opened and there is no turning back. Diesel flows through at 10 gallons per hour, and explodes into a fireball, beautiful and scary. We throttle up the oxygen flow, 150 psi, now its roaring. 200 psi, what in the world are we doing, the flame is now retreating into the cone expected from a rocket. 220 psi, the engine is roaring at nearly full throttle, the most rewarding sound to date, so much louder than expected. So much more satisfying than I could have ever imagined.
We may never know how much thrust the test produced, or what class our engine falls into, or the specific impulse of Epoch 1. However, what we can say is that it was a rousing success, and that it only gets better from here, bring on Epoch 2.