space-to-space applications require considerably lower levels of power delivery. The reason for this difference is that in space-to-Earth applications, we must deliver power levels that are competitive with ground-based sources. If we ever hope to replace unsustainable ground-based energy sources with space solar power, we must be able to deliver similar amounts of power to Earth from space. On the other hand, in space-to-space applications, even a low level of power beaming may be able to find a profitable market in the areas of satellite lifetime extension and power delivery to eclipsed objects. The 1992 summer session of the International Space University (ISU), held in Kitakyushu, Japan brought together 130 students from 30 nations to study all fields related to space. Ranging in experience from university degrees to long-term work backgrounds in the space industry, the ISU '92 student body was multi-disciplinary and multi-cultural, and had an interest in the future of space exploration and development. One facet of the summer session's work was to produce the present design report for a Space Solar Power Program. Unlike many previous studies of space solar power, this study is intended to be comprehensive in its scope — instead of focusing on just one subset of the technical problems related to space solar power, as previous studies have done, this study explores all the aspects of creating a commercially viable space solar power industry. In this way, this broadspectrum, international analysis may be a useful resource for future research in space solar power. The Space Solar Power Program will be a grand cultural project of similar scale and importance to other great unifying cultural projects of the past — the Roman aqueducts and roads, the Great Wall of China, the rail systems of various nations, project Apollo, etc. space solar power will help to bring about a sustainable energy ecology on the Earth. Also, through its space to- pace applications, the program will also make an important contribution to humankind's development of space. In the longterm, it will help unite governments, space agencies, industry, environmental groups, and the public behind a common cause of benefit to all. And it will provide safe, accessible, affordable energy to developing nations and to isolated locations, which could be an important contribution to the process of raising the global standard of living on Earth. However, the task of significantly contributing to the world's energy needs is not easy: with today's global energy demand of 13.5 terawatts (this will be discussed further in section 1.4), a visible solar radiance of 1.3 kW/m2, and a power conversion factor from space solar power to usable electric power on the Earth of 10%, we end up requiring a solar radiance collection area of 300 x 300 km2. Clearly, such a large solar collection area is presently beyond our capabilities and much work has to be done to enable space solar power to make such a large contribution. However, even though it may be beyond our present means, we should still uphold the goal of eventually making a significant contribution to die world's energy needs with space solar power. For it will be this goal which brings about the motivation and funding necessary to building a future in which such a contribution is feasible. Depending on the outcome of technological research and design trade-offs, solar power from space may take many forms. For example, it may evolve either as a constellation of large satellites which are visible from the Earth, or as a large moon-based system, or as a combination of both. The tradeoffs to be made will be truly multidisciplinary, including political, safety and esthetical arguments, as well as technical and business arguments. But whatever the final system, we recommend that it satisfies the criteria for a better energy source as listed above. The Space Solar Power Program is, by anyone's standards, an ambitious program. However, we believe that with careful planning and a long-term commitment, such a program can be realized. We envision a future in which space solar power is an important and positive part of the Earth's energy system. We conceive of a future in which humanity has moved into space, not to escape a ruined world, but to broaden the horizons of a thriving home planet, and we hope that space solar power will be a valuable contribution to this future. 1.2 Space Solar Power Program Statement of Work The task for the 1992 International Space University Space Solar Power Program design project was to consider a full development program from the present state of technology until the point that large international solar power satellites (on the order of gigawatts) are fully commercially operational. This development plan will contain near and far-term milestones. The objective is a global analysis of the program and a more detailed analysis on the near-term milestones. The end-product of the project addresses technical, business, political, environmental, safety, social aspects, and provides a set of recommendations and critical issues.
RkJQdWJsaXNoZXIy MTU5NjU0Mg==