The desire to travel into space is as old as mankind itself. But it was not until the beginning of the 20th century that the idea became anything more than fiction. Although hot air balloons large enough to carry a person lifted off the ground in the late 1700s, it was the invention of powered flight-the airplane-that gave man hope of controlling his ascent into the skies and beyond. Once man was headed up, he could never again be satisfied being...