Even before the launch ofthe first artificial Earth satellite
by the Soviet Union shocked the world, the fundamental
foundation for manned space flight, with its ultimate ob
.ective ofleaving the confines ofthe Earth for the Moon
and more distant celestial bodies,had been laid. In 1903
Konstantin E. Tsiolkovsky (1857-1935), the father of Russian
cosmonautics, published his landmark treatise on the technical requirements
for space flight, Investigation ofCosmic Spaces by
Reactive Devices. His pioneering work was supplemented by
Tsander (1887-1933)andKondratyuk (1897-1942).Ascanthalfcentury
later, Russian scientists and engineers began turning
Tsiolkovsky's dream into reality. By the timeYuri Gagarin marked a
milestone ofhuman evolution by becoming the first man in space,
the seemingly impossible task oflanding men on the Moon and
returning them to Earth had been reduced to a technical and engineering
challenge well within the grasp ofthe current generation.