Throughout history, people have tried to understand Earth's place in the universe and what else, if anything, is 'out there'. This common human curiosity has led to great discoveries, from astrologers in ancient Babylon and Egypt who sought to link the strange planetary paths through the night sky to human behavior, to the 17th century when Galileo turned his first telescope on the night sky, to the 21st century when robotic explorers landed on Mars. "Exploring Space, Revised Edition" offers extensive coverage of human explorations into space - from 19th-century fantasy to 20th-century achievement and the future of space exploration in the 21st century - giving up-to-date information about the current state of exploration in the final frontier. Coverage of this title includes: native American astronomy; the U.S.-Soviet 'race to the moon' in the 1960s; how astronomers began to realize that Earth was only one of several planets; the challenges NASA has faced, such as the explosions of the Challenger and the Columbia Development of space stations; and, an examination of the future of space exploration.