High Voltage Solar Array Development for Space and Thruster-Plume Plasma Environments

High power solar arrays are in development by NASA for near term high power solar electric propulsion (SEP) missions. These high voltage solar arrays utilize deployable flexible blanket configurations and need to be able to operate in the plasma environment of high power Hall thrusters operating at 10’s of kilowatts of power. Array voltages of 300 to 800 V are desired both to minimize the copper-bus mass in the system, and to potentially operate the SEP Hall thrusters directly at high specific impulse without an in-series power processing. Coupons with several strings of solar cells are tested to high positive and negative bias in a plasma environment representative of the edge of Hall thruster plumes. Proper encapsulation of the exposed metals and triple-points is required to avoid excessive current collection and arc initiation. Fully encapsulated test coupons have been successfully tested at the highest anticipated thruster-plume plasma densities at voltages from 600-1000 V, which enables both very-high power arrays and direct drive configurations for SEP missions.