The Space Shuttle hypergolic primary reaction control system (PRCS) thrusters continue to fail-leak or fail-off at a rate of approximately 1.5 per flight, attributed primarily to metal nitrate formation in the nitrogen tetroxide (N2O4) pilot operated valves (POV's). The failures have continued despite ground support equipment (GSE) and subsystem operational improvements. As a result, the Johnson Space Center (JSC) White Sands Test Facility (WSTF) performed a study to characterize the contamination in the N204 valves. This study prompted the development and implementation of a highly successful flushing technique using deionized (DI) water and gaseous nitrogen (GN2) to remove the contamination while minimizing Teflon seat damage. Following flushing a comprehensive acceptance test is performed before the thruster is deemed recovered. Between the time WSTF was certified to process flight thrusters (March 1992) and September 1993, a 68 percent thruster recovery rate was achieved. The contamination flushed from these thrusters was analyzed and has provided insight into the corrosion process, which is reported in this publication. Additionally, the long-term performance of 24 flushed thrusters installed in the WSTF Fleet Leader Shuttle reaction control subsystem (RCS) test articles is being assessed. WSTF continues to flush flight and test article thrusters and compile data to investigate metal nitrate formation characteristics in leaking and nonleaking valves.


    Zugriff

    Zugriff über TIB

    Verfügbarkeit in meiner Bibliothek prüfen


    Exportieren, teilen und zitieren



    Titel :

    Space Shuttle Reaction Control System Thruster Metal Nitrate Removal and Characterization


    Beteiligte:

    Erscheinungsdatum :

    1993


    Format / Umfang :

    11 pages


    Medientyp :

    Report


    Format :

    Keine Angabe


    Sprache :

    Englisch




    SPACE SHUTTLE REACTION CONTROL SYSTEM THRUSTER METAL NITRATE REMOVAL AND CHARACTERIZATION

    Saulsberry, R. L. / McCartney, P. A. / United States | British Library Conference Proceedings | 1993



    Space Shuttle reaction control thruster

    STECHMAN, R. / LYNCH, R. | AIAA | 1974


    Shuttle Reaction Control Thruster Plume Diagnostics

    Kurtz, J. J. / Starritt, L. / Nam, M. K. et al. | British Library Conference Proceedings | 1995