Page:This New Ocean, a history of Project Mercury, Swenson, Grimwood, Alexander (NASA SP-4201).djvu/28

RV 13 (THE LURE, THE LOCK, THE KEY) pressurized cabins on high-altitude airliners featuring an unprecedented combination of speed and luxury. It appeared that man at last had accomplished what the ancients had dreamed of—conquest of the air.

Space flight, however, was something else. While in one sense atmospheric flight was the first step toward space flight, extra-atmospheric transport involves much more than a logical extension of aviation technology. The airplane, powered either by a reciprocating or a jet engine, is a creature and a captive of the atmosphere, because either pbwerplant depends on air—more properly, oxygen—for its operation, and in space there is no air. But the rocket, unlike the gas turbine, pulsejet, ramjet, or piston engine, needs no air. It carries everything needed for propulsion within itself—its own fuel and some form of oxidizer, commonly liquid oxygen, to burn the fuel. So the rocket engine operates independently of its environment; in fact, its efficiency increases as it climbs away from the frictional density of the lower atmosphere to the thin air of the stratosphere and into the airlessness of space.

Yet even the rocket research airplanes were a long way from spacecraft. Although some of these vehicles provided data on the use of reaction controls for steering in the near vacuum of the upper atmosphere, they were designed to produce considerable aerodynamic lift for control within the lower atmosphere; and, in terms of the mass to be accelerated, their powerplants burned too briefly and produced too little thrust to counterbalance the oppressive force of gravity. Fulfillment of the age-old desire to travel to the heavens, even realization of Hale’s nineteenth century concept of a manned sphere circling Earth in lower space, would have to await the development of rockets big enough to boost thousands of pounds and to break the lock of gravity.

Although black-powder rockets, invented by the Chinese, had been used for centuries for festive and military purposes, not until the late nineteenth and early twentieth centuries did imaginative individuals in various parts of the world begin seriously to consider the liquid-fueled rocket as a vehicle for spatial conveyance. The history of liquid-fueled rocketry, and thus of manned space flight, is closely linked to the pioneering careers of three men—the Russian Konstantin Eduardovich Tsiolkovsky (1857–1935), the American Robert Hutchings Goddard (1882–1945), and the German-Romanian Hermann Oberth (1894–).

Tsiolkovsky, for most of his life an obscure teacher of mathematics, authored a series of remarkable technical essays on such subjects as reaction propulsion with liquid-propellant rockets, attainable velocities, fuel compositions, and oxygen supply and air purification for space travelers. He also wrote what apparently was the first technical discussion of an artificial Earth satellite. Although virtually unknown in the West at the time of his death, in 1935, Tsiolkovsky was honored by the Soviets and had helped establish a long Russian tradition of