ISS plasma contactor current emission versus model prediction

We have written a monitoring software package, PCMonitor, that compares in real time the measured current emitted by the International Space Station (ISS) Plasma Contactor Unit (PCU) with the current predicted by the models used to design the PCU. In the absence of a direct measurement of the ISS chassis potential, this comparison is the only way to determine if the chassis potential is within + 40 V of the local ionosphere as specified by requirements. The potential must remain within this range in order to avoid arcs on the anodized coatings. PCMonitor is designed for USC by engineers with little experience in spacecraft plasma environment interactions, but a need to monitor PCU operations.