It is most important for key members of this project to recognize the importance of SPS and its basic problems. International Geophysical Year Importance of the environmental issue of the SPS was pointed out at the same time that it was proposed. The SPS is the first energy system for which the environmental effect has been assessed prior to the start of its development (2). Concerns prevail about the effect of energy dissipation into the atmosphere due to energy transmission by radiation on the climate change of Earth. Actually consumption of the conventional energy will have a similar effect on Earth. For example, increase of carbon dioxide in the atmosphere and floating dust of the combustion product which is produced not only by electrical powerplants but also by automobiles and other facilities consuming fossil fuels is observed. Thus, to know what the Earth environment is in the scale of a planet and how it is changing has the same importance as to know the effect of rocket exhaust products, dissipation of transmitted energy in the atmosphere and other sources of pollution supposed to be caused by the SPS, because the latter will be evaluated by reference to the former. The former activities are represented by the International Geographic Year research, which is typical multidisciplinary research. It should be emphasized that such scientific enterprise should be undertaken in the near future and special consideration is required to determine the global environmental condition on that occasion. 5. EVOLUTION OF JOBS OF MAJOR DISCIPLINES Multidisciplinary research activities are important during the whole project, because R&D activities will be required from the beginning through operations of the early operational model. Cooperation of multidisciplinary research activities involves different combinations of jobs. The type of jobs of disciplined area differs with progress of the SPS project and the sequence of jobs are different for individual areas. An approach to make such a job plan will be discussed here. To handle the macro-project of SPS more easily, an idea of macro-phasing was proposed to divide the SPS project into three phases as depicted by Fig. 3, where each phase is featured by a main experimental facility (4). Macro-phase I. The main facility of this phase is the Space Station and one concept has been presented here. The central facility is considered to be experimental equipment of SPS which will provide technical data for the future system design. The experimental operations will include experiments of technologies to be used for SPS and the receiving facility. The electrical propulsion test is directly related to the orbital space transportation of the SPS. Environmental study of this phase will be basic data collection required for experimental study of the next phase. Macro-phase 2. It is assumed that, in this phase, an intermediate scale model between the space station and the 1 GW operational model will be constructed and test- operated. According to a preliminary study (4), the experimental study is possible for such disciplined areas as the SPS system design, long period heating of the ionosphere, operation of power receiving station, Earth-to-low Earth orbit transportation operation and electrical propulsion system operation. Critical hardware for the SPS and the receiving station facility will be developed for the operational model of the
RkJQdWJsaXNoZXIy MTU5NjU0Mg==