A plume diagnostic based engine diagnostic system for SSME

In FY88 a project was undertaken at the stennis Space Center (SSC) to develop a plume diagnostic based Engine Diagnostic Console (EDC) for ground test operations of the Space Shuttle Main Engine (SSME) . The goal of the project was to develop a smart EDC to provide on-line real-time information concerning the health and condition of the engine. To provide this information a spectroscopic system was selected to monitor elemental emissions from abnormal wear of critical comwonents and materials exposed to the hot gas path of the SSME. A prototype EDC was demonstrated in FY89 using SSC’s Diagnostic Testbed Facility (DTF) thruster engine and a NASA project was initiated to provide EDCs at all SSC test stands. EDCs are currently installed in two of the three SSME test stands at the stennis Space Center. These systems use commercially available optical multichannel analyzer spectrometers and video systems to display plume video and spectral data on-line in near real-time at the test control center. This paper discusses the current status of EDC development and application on SSME test stands at SSC, presents data from.the thruster engine plume seeding experiments ,used for EDC development and EDC data from SSME firings on ambient and simulated altitude test stands, including recent spectral data which show precursors to an engine anomaly.