[Hypobaric atmosphere and decompression safety of outer space explorations on the first days of flight]

54 subjects aged 21-47 participated in 8 series of experiments (298 altitude investigations) aimed at selecting decompression-safe protocols for transition from hypobaric normoxic environment to reduced pressure. Experimental data is discussed and some protocols for safe transition to reduced pressure are recommended. The experiments allowed to display in diagram form the ratio of permissible magnitudes of residual pressure (the working pressure in the extravehicular suit) to the duration of a preliminary exposure in normoxic hypobaric conditions.