On April 26, 1961, 2 weeks after the orbital flight of Gagarin, the
Embassy of the Union of Soviet Socialist Republics in Washington, D.C.,
issued certain medical data about the mission.8
The release read in part:
To provide answers to the medicobiological problems posed by space flight, it was reported, Soviet scientists since 1951 had carried out experiments with flights of animals in rockets to altitude up to 450 kilometers (approximately 280 miles). Later, artificial earth satellites were used for making biological experiments—for example, it was considered important to study with maximum accuracy the biological effects of cosmic radiation. As a result of experimentation, orbital flight below the radiation bells was found to be safe for organized representatives of the animal world. It was therefore concluded that manned flight could be undertaken without harm to the cosmonaut's health.
The cosmonauts' training had included, among other subjects, orientation in space medicine. Also included were special training and tests in aircraft flights under conditions of weightlessness, training in a simulated spacecraft cabin and on a special training machine, prolonged stay in a specially equipped sound proof chamber, centrifuge tests, and parachute jumps from aircraft. Cosmonauts had to be able to stand the state of weightlessness for as long as 40 seconds and to partake normally of liquid, semiliquid, and solid food during that time. They also had to he able to discharge such functions as writing, radio communication, and reading, and to maintain visual orientation in space. Physiological studies and special psychophysiological methods "permitted the selection of people best fitted to discharge the missions accurately and who had the most stable nerves—emotional health," according to the Soviet report of April 26, 1961. The future cosmonauts "systematically did physical exercises to raise the organisms' resistance to acceleration forces as well as other factors of the new medium," it was reported. From the group of cosmonauts thus trained, Gagarin had been chosen to make the first orbital flight.
From the foregoing description, it is apparent that the U.S.S.R. and the U.S.A. had approached the problem of selection and training of the astronauts in much the same manner, following the traditional methods of selection and training of pilots. The main difference in the biological-medical procedures had been that the U.S.S.R. had carried out more extensive animal experimentation than had the United States.
A major difference in the approach, however, had been in the development of the life-support systems of the spacecraft. For Gagarin's flight the air-conditioning system maintained normal pressure and normal oxygen concentration in the pilot's cabin: The concentration of carbon dioxide did not exceed 1 percent. The temperature ranged from 15° to 22° C and the relative humidity from 30 to 70 percent. The air was regenerated chemically, and the heat in the pilot's cabin was absorbed by a liquid cooling agent. Gagarin wore a protective space suit.
The journal Meditsinskiy Rabotnik (Medical Worker) reported that Gagarin ate solid, pastelike, and liquid food during the flight. His menu was designed to avoid both overcharging the digestive system and accumulating excessive cellular tissue. He had no difficulty eating in the condition of weightlessness. Prior to flight he had tested foods prepared for consumption in flight and had chosen his favorites. "It is important," wrote G. F. Arutyunov (Master of Science in Medicine), "to have all the constituents of the food ration assimilated by the organism to the utmost."10
The major problem with which the Russians had wrestled prior to manned orbital flight was that of reentry. In August 1958 they had sent two dogs on a ballistic flight to an altitude of 280 miles with successful recovery by ejection of the dog containers during the descent. Subsequent development and testing led to the system used by Gagarin, which included a descent phase lasting approximately 30 minutes. In case the braking engine failed, the ship was designed to take advantage of atmospheric drag. The cosmonaut would make a landing on dry land, as contrasted with the Mercury landings on water.11
On August 6, 1961, after Grissom's suborbital flight in July, the U.S.S.R. launched Cosmonaut Gherman S. Titov into orbit in a spacecraft (Vostok II) weighing 1.7 pounds more than Vostok I, launched the previous April. (On the same date the report of the Space Science Board of the National Academy of Sciences was released: it recommended exploration of the moon and planets as the official goal of the U.S. space program.) The following day, August 7, it was reported from Moscow that Major Titov had successfully landed in Vostok II after 17 orbits in 25 hours 18 minutes. This was the first manned flight of more than one orbit, and the first test of man's reaction to prolonged weightlessness.12
Other medical information would be forthcoming shortly.
8. Press Release No. 109, Embassy of the Union of Soviet Socialist Republics, Apr. 26, 1961.
10. As cited, ibid.
11. Ibid. See also D. I. Fryer, "The Medical Sciences and Space Flight," R.A.E. News, Feb 1964.
12. Aeronautical and Astronautical Events of 1961, op. Cit., p. 38.