Are we at the beginning of another Age of Exploration Perhaps even more important, are we at the beginning of 【B1】 Age of Colonization As the population of the world increases towards the point 【B2】 the earth can no longer support all the people 【B3】 on it, the second question becomes urgent. Will we discover a new world, 【B4】 Columbus did, on which human life will be possible At this point in the space age, no one can really answer these questions. We can say, 【B5】 mat we will not see tomorrow the kind of space travel that 【B6】 fiction and the movies have shown. It will be a long time before we have flight that run 【B7】 to human colonies on the moon or on one of the planets. We are not even going to be able to 【B8】 immediate advantages of the minerals that we may find on the planets 【B9】 our own solar system.
Great problems must be solved 【B10】 we could send colonies out into place. The distances that must be 【B11】 and the length of time it takes to do that can hardly be 【B12】 There are also dangers that we still do not really understand—from radiation, for example, or from pieces of matter 【B13】 in space, or from contamination from forms of life that might 【B14】 there. There is also need for humans to take their own environment into space 【B15】 them. So far no "island" has been discovered in space on which people can exist without systems that 【B16】 life, and these systems must accompany any future space 【B17】 Finally, on the most practical 【B18】 there has to be enormous expense 【B19】 in space exploration. The U.S. and Russian governments have already spent billions of dollars for projects 【B20】 which they can receive a return only in knowledge and not in money.