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This paper reports on the development and demonstration of a unique distributed Power Management and Distribution (PMAD) architecture developed for the PowerSphere concept. The PowerSphere PMAD concept was conceived as a solution for providing adequate electric power from solar cells to power a Micro-satellite or Nano-satellite. The PMAD architectural concept developed for the PowerSphere accommodates its arbitrary orientation by unique features. The architecture has all of the individual power sources and storage devices connected in parallel to a regulated spacecraft power bus. This parallel connection is accomplished via a microelectronic dc-dc converter for each power or storage device. This direct connection eliminates the need for series connections of these devices to produce sufficient voltage to supply the bus.

Optimal power generation and storage technology suites must be selected based on the overall spacecraft mission and hardware design to insure a minimum system cost. Several new technologies in solar generation (high efficiency multi-junction GaAs-based cells, concentrator arrays, thin film cells, etc.) offer increased performance and/or reduced system-level cost. The savings at the array level often benefit the overall system performance in terms of drag, mass, inertia, and propellant loading. In addition, battery technologies often impact the spacecraft thermal control system and overall dry mass. This paper discusses the design algorithms implemented and executed at The Aerospace Corporation to determine optimal power subsystem suites as a function of spacecraft design and total system cost.

This paper addresses whether sufficient service can be expected from a satellite which has been stored on the ground for significant periods of time prior to launch. The technical issues which limit a satellite's lifetime have been examined and indicate that terrestrial storage will not have an appreciable adverse effect on the operational lifetime of a satellite if proper storage precautions and testing procedures are followed. These storage procedures include atmosphere type specifications, temperature and humidity levels, frequency of in-storage maintenance or testing and the type of post-storage testing. The results of this effort and others like it have been compiled to develop a baseline Space Division pamphlet which is designed to provide guidelines to ensure the most effective storage environment and testing program for Air Force satellites.