The design and expected performance of large-area close-packed square and rectangular solar cell arrays are described. This includes the basic properties of the solar cells and calculations performed during the design stage and calculations to predict the expected results. A description of the module design, the rationale for, and the specifications of the components to be used in the modules, is given. The test results are given, which includes the results of pre-production humidity and thermal cycling testing, as well as the final test results from measurements both at Solarex and at JPL. An economic analysis of high density panel production, as well as design recommendations and conclusions drawn from this program are included. (WHK)