Here, in word and picture, is the story of man's first probe into space. Vanguard and Sputnik are only one side of the story--the International Geophysical Year is the first concerted international effort to advance our knowledge not only of space but of earth and sun. Sydney Chapman, leader of the team of scientists that directed the program, re-creates for the general reader the discoveries that will provide the basis for our exploration of space. He describes how scientists from 67 nations pooled their resources and techniques to explore our corner of the universe—with satellites and rockets, the voyage of the "Nautilus" under the polar ice cap, teams of amateur moonwatchers—and what their discoveries mean for our future.