In the early 1950s an acceleration of efforts in upper-atmospheric and space medical research accompanied the quickened pace of rocket development in this country and in the Soviet Union. During the next few years medical specialists, profiting from substantial progress in telemetering clinical data, learned a great deal about what a man could expect when he went into the forbidding arena of space.1 Much of the confidence with which the engineers of Project Mercury in 1958 approached the job of putting a man into orbit and recovering him stemmed from the findings of hundreds of studies made in previous years on the human factors in space flight.
Since the National Advisory Committee for Aeronautics was interested almost exclusively in the technology of flight, research in the medical problems of space flight, like aviation medicine in previous decades, was the province primarily of the military services and of some civilian research organizations receiving funds from the military. Of the three services, the United States Air Force, rich in background in aeromedical research and assuming that space medicine was but  an extension of aviation medicine, undertook most of the early inquiry into the psychophysiological problems of extra-atmospheric flight.
1 On advances in telemetry since the Second World War, see Wilfred J. Mayo-Wells, "The Origins of Space Telemetry," in Eugene M. Emme, ed., The History of Rocket Technology: Essays on Research, Development, and Utility (Detroit, 1964), 253-268; also published in Technology and Culture, IV (Fall 1963), 499-514.