Odyssey Hot Fire 02

Owned by Cameron Sexsmith
Dec 20, 2023
2 min read

 

Background

This test sought out to attempt the throttling milestone for the Lander Challenge. From the collected data from the previous hot fire (Odyssey Hot Fire 01), the engine would need to operate at a higher pressure and flow rate to attain the required thrust for the milestone. The run tank pressure was increased from 1000 PSIG to 1100 PSIG for this test. We believed this would give us the bump over the 500 lbf thrust requirement. The test was using the throttling system described in Throttle Mechanism. The engine was cleaned and refurbished to the best of the team’s abilities. This test also included upgrades to the feed system including a new stainless steel propellant run tank, and tube runs in place of hoses. The test also featured a safer remote filling mechanism using the same architecture as the throttling valve. Slight pitting to the injector face was not corrected.

 

Results

The test progressed with minimal issues with all the new hardware. This electronics team tracked no issues other than a bad redundant sensor not needed for operation of the system. This test required almost a completely full run tank for the test which caused a minor problem during fill. The pressure in the supply tanks and run tank equalized which caused a stop in the filling. For this, we cycled the vent valve to allow for more liquid nitrous oxide to flow into the run tank. This process was repeated until 40 pounds of nitrous oxide was loaded. The ignition process was handled using an upgraded auto-sequence than handled ignition of the pyro-grain, actuation of the main oxidizer valve, and the throttle valve. Upon ignition, the engine ignited perfectly and proceeded to operate nominally for roughly 8 seconds. At roughly the 8 second mark, the injector face began to fail and two burn-throughs occurred on the injector element. These burn-throughs caused an increase in oxidizer flow rate which progressed the erosion of the phenolic liner in the combustion chamber. This progressed erosion then led to two burn-throughs in the combustion chamber eventually leading to a complete loss of the engine.

Sorry for the poor axes labels. Thrust is in lbf and pressure in PSIG. Throttle goes from 100% open to 30% at the lowest point. More pictures can be found in the document attached below with further breakdown on the post-test engine failure.