Fault tree analysis for risk assessment of rocket engine testing process at high altitude test facility

The paper focuses on reviewing systems of an operational test facility for high altitude testing of Liquid Rocket Engine (LRE) in terms of risks associated with the testing process. Owing to high altitude testing requirements, the likelihood and criticality of failure in both Propellant Feed System (meant to maintain inlet conditions to LRE) and Second Throat Ejector Diffuser System (meant to maintain outlet vacuum requirements of LRE) have been addressed. ‘Delay in successful test’ has been identified as the top event and this has been broken down using logic diagrams of a Fault Tree Analysis (FTA) with best possible efforts to understand probable interactions between heterogeneous components of the test facility which may lead to nonperformance. Identification of items attributing to single point failures enables criticality-based assignment of priority to various facility systems, in terms of operation and periodic maintenance. The ultimate objective remains to establish a robust and reliable testing process by proactively mitigating identified risks, thus preventing any unplanned delay due to facility related anomalies during LRE testing.