Instrumentation design considerations for automatic ground testing of rocket engines

Ground testing (qualification and acceptance) testing of integrated rocket engine (thrust chamber, turbopumps, gas generators, steering engines etc.) is mandatory before actual launch. Since the rocket engine operates with hazardous cryogenic fluid, handling and disposing is also critical tasks. Above all, the safety of test stand, working personnel, Test article Under Test (TUT) and environmental safety is paramount importance. The instrumentation system for testing a rocket engine consists of a programmable automation controller(PAC) based control system, sensors, signal conditioning system, field actuators, network system, data storage as well as retrieval and archiving system. The main challenges in designing the instrumentation systems are availability of the system, real time software, fast reaction time, high bandwidth data and statuary safety requirements. This paper addresses some key issues with respect to design of the instrumentation system requirement for ground testing of rocket engine adhering to standards such as IEC61499(Distributed Industrial Automation System), IEC61131-3(Programming Language) and IEC61508(Standard for Functional Safety).