[01] Mohammed Bekhti, Centre for Satellites Development, Ibn Rochd, USTO, Oran, Algeria.

In order that photovoltaic solar cells may be used more effectively to provide electrical power for spacecraft, it is desirable to refine the engineering design of solar cells and power systems, based on a better understanding of the space radiation environment and of radiation damage effects on semiconductor components. The objective of this paper is to provide the reader with some of the useful ideas and test data which can be applied in designing radiation resistant power systems. It is found that the most serious obstacle which prevents accurate prediction of solar cell degradation for earth satellites is our inadequate knowledge of the fluxes and energy spectra of electrons and protons in the magnetosphere. When the space environment can be better defined, it will be possible to predict more accurately the degradation of present day types of silicon and GaAs solar cells, for which the radiation damage characteristics have been quite well determined by laboratory research. As improved types of solar cells and materials become available, it will be necessary to make laboratory measurements of their radiation resistance to protons and electrons in order to predict their performance in space. The advances in technology are nowadays allowing the production of solar cells in different sizes and more importantly with increased efficiencies exceeding 30%. However, these semiconductors can suffer a great deal of degradation in performance when hit by high energy electrons and protons. The paper will attempt to identify areas where an improved understanding of defects behavior is necessary to produce further improvements in performance. From, the results in this paper, all the compiled telemetry data and the predefined assumptions show that Alsat-1 solar panels did not suffer a high level of degradation and that the real degradation never reached those assumptions made during mission analysis and design phases [1][2][3][4][5].

Space Degradation, GaAs Solar Cells, Aluminum Honeycomb, Ultrasonic Welding, Insulation Layer, Irradiation Effects, Design Procedures, Electron and Protons

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