LEO spacecraft leakage current and discharging phenomena: TRW LDEF SP-HVDE (space plasma-high voltage drainage experiment)

Two identical SP-HVDE solar cell trays were flown in the NASA 5.75-year LDEF (Long Duration Exposure Facility), one near the leading edge and the other near the trailing edge, in the LEO (low Earth orbit) environment. Each experiment tray consisted of six assemblies with each made of Kapton dielectric samples of varying thickness (i.e., 2 mils, 3 mils, and 5 mils) biased under +or-300 V, +or-500 V, and +or-1000 V. The objectives have been successfully achieved by measuring the first post-flight long-term (i.e. roughly 8-month experiment) average leakage current through 95% measurable coulombmeters and surface materials.<>