Half Cat Static Test 1 - December 15, 2021

• Partial Success (propellant tanks exploded post-firing)

• No numerical data acquired

• Changes from previous test: N/A (well, a lot if you consider the many, many previous iterations of the engine)

Many attempts were made before finally achieving a hot fire (most prior problems involving the electronics in the GSE, after the leaks had been solved), but eventually Half Cat came to life just days prior to our graduation, making this the first liquid bipropellant engine from students at UCF. The burn itself was nominal, but in the minutes following shutdown residual gaseous nitrous oxide continued leaking into the combustion chamber where it kept the remains of the thermal liner on fire until this caused a N2O decomposition event originating at the bottom center of the tanks. The detonation destroyed both tanks and the lower tank bulkhead as well as causing the piston to vanish at speed (we assume it was shot off into the grass, but it is also possible that it was broken into many small pieces and scattered).

Following this test, a new fuel tank, piston, and lower tank bulkhead were fabricated along with a “new” oxidizer tank, which was in fact the originally intended tank before it was switched out for the identical tank belonging to the cold gas CO2 thruster. The lingering fire of the thermal liner spurred the creation of CHAMBERSAFE to eliminate that particular decomposition risk.