INTRODUCTION
Long ago, human imagination created a world of mythical beings to explain the wonders of the visible heavens. This world, occupied by an assortment of larger than life reflections of human experience and personality, provided what seemed to be a rational and colorful explanation of the mysterious and obviously powerful events taking place in the sky. The creation of myth was driven by the human need to understand and explain the universe. During ancient times, observation was so limited that it was left up to our imagination to explain what we were seeing in the sky.All this has changed. Over the last several hundred years, observational astronomy has progressed to the point where both human and robotic space flight are contributing to and refining our ideas of how the universe is put together. In modern times, we have learned that the stars and planets are not great living beings, but in fact are great masses consisting of gases, liquids, and solids waiting to be understood even more by the human mind.
Today, outer space is an exciting part of all of our lives. It provides us with a unique laboratory, allowing scientific studies never before possible in the history of civilization. Results from experiments in the laboratory of space will touch and influence nearly every part of our lives, including computers, technology, medicine, psychology, business and enterprise. Future large scale laboratories, such as a permanently manned space station and/or a base on the moon, are already in the planning stages. Future exploratory missions involving humans, such as a trip to Mars and back, are also being actively discussed by scientists and engineers today, whereas only decades ago such voyages were the subject of science fiction. Many of these plans will become a reality in your lifetime; still, there is much to be done and much to be learned before we can accomplish these goals.
