A Step Farther Out Read Online Free PDF Page A

the nutrients fall to the bottom where there is no sunlight; while at the top there's plenty of sun but no phosphorus and other vital elements. Thus most ocean life grows in shallow water or in areas of upwelling, where the cold nutrient-rich bottom water comes to the top.
    More than half the fish caught in the world are caught in regions of natural upwelling, such as off the coasts of Ecuador and Peru.
    The OTS system produces artificial upwelling; the result will be increased plankton blooms, more plant growth, and correspondingly large increases in fish available for man's dinner table. The other major pollutant is fresh water, which is unlikely to harm anything and may be useful.
    Certainly there are some engineering problems; but not so much as you might expect. The volumes of water pumped are comparable to those falling through the turbines at a large dam, or passing through the cooling system of a comparable coal-fired power plant. The energy itself can be sent ashore by pipeline after electrolysis of water into hydrogen and oxygen; or a high-voltage DC power line can be employed; or even used to manufacture liquid hydrogen for transport in ships as we now transport liquid natural gas.
    As to the quantity of power available: if you imagine the continental United States being raised 90 feet, forming a sheer cliff from Maine to Washington to California to Florida and back to Maine; then pour Niagara Falls over every foot of that, all around the perimeter forever; you have a mental picture of the energy available in one Tropic, one band between the equator and the Tropic of, say, Cancer. It is more than enough power to run the world for thousands of years.
    Finally the feasibility of OTS: in 1928 Georges Claude, inventor of the neon light, built a 20 kW OTS system for use in the Caribbean. It worked for two years. One suspects that what could be done with 1928 technology can be done in 1988.
    OTS is not the only non-polluting system which could power the world forever. Solar Power Satellites would do the task nicely. SPS will be discussed in later chapters; but few doubt that they could provide more than enough energy to industrialize the world, and we understand how to build them far better at this moment than we understood rockets on the day President Kennedy committed us to going to the Moon in a decade.
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Figure 5

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    That is a point worth repeating: we can power the Earth from space. We do not "know how to do it" in the sense that all problems are solved; but we do know what we must study in order to build large space systems. When John F. Kennedy announced that the United States would land a man on the Moon before 1970, the reaction of many aerospace engineers was dismay: not that anyone doubted we could get to the Moon, but those closest to the problem were acutely aware of just how many details were involved, and how little we had done toward building actual Moon ships. We had at that time yet to rendezvous or dock in space; there were no data on the long-term effects of space on humans; we had not successfully tested hydrogen-oxygen rockets; there were guidance problems; etc, etc. Thus the dismay: there was just so much to do, and ten years seemed inadequate time in which to do it.
    Solar Power Satellites, on the other hand, have been studied in some detail; and we have the experience of Apollo and Skylab. We know that large structures can be built in space; they require only rendezvous and docking capabilities, and we've tested all that. We know we can beam the power down from space; the system has been tested at JPL's Goldstone, and the DC to DC efficiency was 85%. There are other problem areas, but in each case we know far more now than we knew of Mooncraft in 1961.
    Ocean Thermal and Solar Power Satellites: either would power the world. I could show other systems, some not so exotic. My engineering friends tell me that OTS and SPS may even be the hard way, and there are much more