SUMMARY This is the Final Report of a feasibility study of a satellite solar power station (SSPS) carried out by Arthur D. Little, Inc., Grumman Aerospace Corporation, Raytheon Company, Spectrolab, a division of Textron Inc., for the National Aeronautics and Space Administration under Contract NAS 3-16804. The primary objectives of this study were (1) to explore how an SSPS could be “flown” and controlled in orbit, (2) to determine the techniques which would be required to avoid radio frequency interference with other users of the electromagnetic spectrum, and (3) to determine the key environmental and economic issues which would have to be assessed. Structure and Control Techniques Structural and dynamic analyses of the SSPS structure were performed to provide elastic characteristics (natural frequencies, generalized masses, and mode shapes) of the structure for use in an analytical investigation of the elastic coupling between the SSPS attitude control system and the spacecraft's structural modes. Deflections and internal member loads resulting from the various flight loading conditions were determined to verify structural integrity. Desirable material characteristics were assessed and technology developments identified to provide inputs leading to the design of stnicture and attitude control systems for the very large-area, light-weight space structures represented by the SSPS. The flight control performance of the SSPS baseline design was evaluated and parametric sizing studies performed to determine the influence of structural flexibility upon attitude control system performance. RFI Avoidance Techniques The study of RFI avoidance techniques included three principal areas: (1) optimization of the microwave transmission system; (2) device design and expected RFI; and (3) effects of SSPS RFI on other users. System Optimization. — To optimize the microwave transmission system, a model and a set of assumptions were first defined. The model included data on orbital and ground location, ground power transmission, device characteristics, phase-front control, efficiencies, RF environment, attenuation, frequencies, users, and equipment. Device Design. — The Amplitron, a very efficient microwave generator, was evaluated from the viewpoint of its design versus its operating frequency for the SSPS concept. The choice of 3.3 GHz as the fundamental frequency for the SSPS was based on a set of assumptions for filter design and recognition of existing allocated radio astronomy and fixed satellite space-to-Earth bands. Effects of SSPS RFI on Other Users. - This phase of the study concentrated on (1) the transmitting antenna and nature of the transmitted beam; (2) the receiving antenna; and (3) noise
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