Future mission opportunities and requirements for advanced space photovoltaic energy conversion technology

The variety of potential future missions under consideration by NASA will impose a broad range of requirements on space solar arrays, and mandates the development of new solar cells which can offer a wide range of capabilities to mission planners. Major advances in performance have recently been achieved at several laboratories in a variety of solar cell types. Many of those recent advances are reviewed, the areas are examined where possible improvements are yet to be made, and the requirements are discussed that must be met by advanced solar cell if they are to be used in space. The solar cells of interest include single and multiple junction cells which are fabricated from single crystal, polycrystalline and amorphous materials. Single crystal cells on foreign substrates, thin film single crystal cells on superstrates, and multiple junction cells which are either mechanically stacked, monolithically grown, or hybrid structures incorporating both techniques are discussed. Advanced concentrator array technology for space applications is described, and the status of thin film, flexible solar array blanket technology is reported.