On the Operational Status of the International Space Station Plasma Contactor Hollow Cathodes

Abstract

*† Two Hollow Cathode Assemblies (HCAs) designated HCA.001-F and HCA.003-F that have been designed and fabricated at NASA Glenn Research Center (GRC) are contained in two Plasma Contactor Units (PCUs) developed by Rocketdyne division of the Boeing Company. The PCUs are installed on the International Space Station (ISS) for the purpose of charge control. NASA GRC’s HCA development program included the manufacture of engineering, qualification, and flight model HCAs as well as qualification and long duration testing. In addition, NASA GRC monitors the on-orbit data for the flight HCAs. As of November 1, 2004 HCA.001-F has been ignited 44 times and has accumulated 4135 hours of operation, whereas, HCA.003-F has been ignited 46 times and has accumulated 6277 hours of operation. Monitored HCAs ignition times and anode voltage magnitudes indicate the two HCAs continue to operate nominally.