An open core rotator design methodology

In low earth orbit [LEO] satellite applications, spacecraft power is provided by photovoltaic cells and batteries. To overcome battery shortcomings, FARE, Inc., working in cooperation with the University of Maryland [UOM] and the NASA Lewis Research Center, has developed an open core magnetically-suspended graphite-epoxy flywheel for energy storage applications. This flywheel energy storage system, called the Open Core Rotator [OCR], was designed to meet specifications set forth by NASA. NASA's primary design requirement called for an OCR system capable of delivering 50 Wh of energy. FARE's OCR is based on and builds upon the fundamental research that has been carried out at the University of Maryland since 1977. The UOM presently has an operational 500 Wh Open Core Composite Flywheel [OCCF]. FARE's OCR is a scaled-down version of the UOM's OCCF. Specifically, this paper discusses the procedure followed by FARE in designing its 50 Wh OCR, including how the resultant dimensions and component topology were obtained.