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Cumulative electrostatic discharges (ESDs) on spacecraft solar cells result in the degradation of their performances. In this paper, silicon solar cells are tested in inverted voltage gradient situation obtained in plasma. ESDs occurring on the cells are detected by both electrical and optical signatures. To be representative of flight ESDs, the test setup must avoid unwanted coupling with ground arcs. The degradation is then evaluated by measuring the current--voltage characteristic of the cell in darkness. The equivalent shunt resistance allows quantifying this degradation, which can be attributed to material deposition on the cell edge or to local cell carbonization due to arcing. Visual inspection of the cells allows us to correlate ESD location and local degradation of the cell. The important parameter for solar cell degradation is the amount of energy dissipated during the discharge. A model of the plasma expansion from the cathode spot is compared to measurement. This model explains the current rise during the first phase of the discharge, which is the same for normal ESDs and coupling with ground ESDs. Index Terms--Arcing, electrostatic discharges (ESDs), plasma expansion model, solar cell degradation.

A good representativeness of the test setup used for the qualification of solar arrays is fundamental. We know now that the flashover current involved in the electrostatic discharge is related with the total dielectric surface neutralized during the electrostatic discharge. This paper presents experiments on samples of different sizes, performed in a large vacuum chamber, JONAS, installed in ONERA/DESP, Toulouse, France. The samples are tested in the inverted voltage gradient configuration obtained with electrons. We observed that secondary arcs obtained on a large sample (i.e., with a long flashover) had much longer durations than those on a small sample, i.e., the flashover is a critical parameter for secondary arc initiation and sustainment. Index Terms--Electrostatic discharge (ESD), plasma generation, solar power satellites.

Because conductivity is not a unique and stable property in space, it implies that we must comprehend as much as possible the different environmental effects that are likely to influence it. Two of these effects, which are radiation (prompt)-induced conductivity (RIC), total dose effects and delayed RIC (DRIC), have been studied at room temperature in the laboratory. In this paper, the surface potential decay method has been used to determine the conductivity of a set of seven materials used in space at two different steps of their expected life in geostationary orbit. Dark conductivity and RIC were determined on pristine samples and also on samples which received a certain level of total dose. The data measured on pristine and aged samples, which have been labeled beginning of life and middle of life, respectively, were incorporated into a material database MATREX into what we called the PIP1 material property list, enlarging the previous NASCAP list. Index Terms--Aging, dose effect, radiation-induced conductivity (RIC), space materials.

Charges accumulate on the spacecraft surface through various processes such as conduction, irradiation, ionization, and polarization. These charges can affect the space system operations via an electric current flowing in the structure or a locally generated electric field. This paper is focused on the analysis of electron behavior in polymeric films such as polymethylmetaacrylate and Teflon subjected to an electron irradiation. The charge distribution is detected during and after the irradiation in situ by pulsed electroacoustic method. Surface-potential and surface-current measurements are also performed to get further information on the charge displacement with time. Index Terms--Dielectric films, electron irradiation, space charge, spacecraft charging.

The detrimental effects of spacecraft charging are well known, particularly when the charging leads to arcing on solar array and, consequently, to permanent power loss. Motivated by these concerns, Alcatel Alenia Space has undertaken several test campaigns to qualify solar array design and to investigate margins. This paper describes the state-of-the-art Alcatel Alenia Space solar array electrostatic discharge laboratory test setup and procedure. The primary discharges are created using a plasma source and negative polarization of the sample rear side. The required power to feed the arc can be delivered by a solar array simulator with low-capacitance power sources. The test sample is fully representative of a flight model. Index Terms--Arcing, electrostatic discharge (ESD), solar array, solar array simulator (SAS).