Development Of An Electrostatic Grounding Technology for JUICE Photovoltaic Assembly

JUICE spacecraft is going to operate in a very harsh charging environment around Jupiter, populated by wide energy range electrons and protons. Electrostatic Discharges (ESDs), triggered by inverted potential gradients, represent a threat to JUICE PVA, as micro-shunts may significantly reduce solar cells' electrical performances in low illumination conditions. In order to mitigate this risk, a specific requirement for the JUICE Solar Array requests not to exceed 1 V potential bias between any two points of the solar generator's surfaces. This article describes the technologies developed up to the qualification phase to fulfill this requirement, by means of a coverglasses' grounding network: starting from a general description, the baseline and the back-up solutions are illustrated in their peculiarities. Then the article provides an overview of the environmental tests that have been performed to validate those technologies; finally, relevant conclusions and further steps are illustrated.