THE SPACB PIOBEBRS In the town of Kaluga south west of Moscow stands a monument to a Russian schoolmaster - Konstantin Eduardovich Tsiol-kovsky. Mot tar away is the brick and timber house in which he lived and which, is now a national museum. At the turn of the century Tsiolkovsky was considered an eccentric dreamer whose theories had little connection with reality. And yet it the Space Age was born anywhere, it was in th< quiet rooms of this humble dwelling. ^ Though he never launched a rocket, Tsiolkovsky's contribution to the science of space travel was immense. He began in 1883 by explaining the principles by which rockets could fly in the vacuum of space. And in "Dream of the Earth end the Sky", published in Moscow in 1885, he made the first mention of the possibilities of an artificial ( BCKyCCTBeHHHB ) aatelite. Then, in 1903, he began to publish selected chapters of his book, "Bxproration of the Universe Space by Reactive Apparatus, which set out tbeoty of rocket flight and the prospects tor space travel. There had, of course, been people before who had dreamed of travelling in space but, on the whole, they lacked the depth of understanding that would point the way to practical engineering achievments. Tsiolkovsky's major contribution was to recommend the use of liquid propellents which not only offered greater performance than the solid variety but could be more readily controlled after their ignition. His first sketch of a spaceship had the shape of a teardrop, with a passenger cabin in the nose and fuel tanks in the rear containing the high-energy propellants liquid oxygen and hydrogen. Within the tank section he drew a long cone-shaped nozzle in which the burning propellents were assumed to explain as a propulsive jet. The same propellant combination eventually would be used by future rockets, which illustrates the remarkable quality of Tsiolkovsky'o ideas. He suggested controlling a rocket'a flight outside the atmosphere by moans of rudders impinging in the exauat, or by tilting the exauat nozzel. He proposed fuel including gasoline. kerosene, alcohol and mataana, worked out methods for controlling the flo" of propellants to the combustion chamber by mixer valves, and advocated coolling the combustion chamber and noze-Ie by passing one of the liquids through a double-walled jacket.