This second edition tells readers why astronauts are weightless, why satellites don't fall from the sky, how we will live on Mars, and whether or not there is life elsewhere in the universe. This book has been updated with recent information on the science and technology involved in the new frontier of space. It is written as a textbook for an undergraduate liberal arts course, with or without mathematics. Subjects covered include the Shuttle, the structure of the sun, various orbits and their uses, international space activities, and astronomy from space. Added to this edition, you will find new and revised illustrations, many of them in colour.