Model Identification for the Space Shuttle Main Engine High Pressure Oxidizer Turbopump

The problem addressed in this paper concerns identification of the input-to-output characteristics of the space shuttle main engine high pressure oxidizer turbopump given measurements of the system output via strain gauges and accelerometers with no exact knowledge of the input. The Eigenvalue Realization Algorithm is used to model spectral characteristics of output signals. The poles and zeros of the system are identified from these models. The analytical background necessary to solve this problem will be developed and then applied to actual preflight engine test data taken at the NASA Stennis Space Flight Center and supplied by NASA Marshall Space Flight Center.