. . . . Icarus, flushed with excitement and exhilaration, soared even higher toward the sun—despite the cries and warnings of his father. At last he flew so high that the heat of the sun melted the wax, and off dropped the wings.
CONTEMPORARY developments in bioastronautics have challenged the once held assumption that "man is a sea-level, lowspeed, one G, 12-hour animal."49 The physical dangers of space flight for the astronaut previously anticipated with uncertainty, have thus far been technologically overcome.2,4,7,9 But even after the successes of recent short-term space explorations,26,27 the question of man's capacity to withstand the emotional and psychological effects of sensory isolation and deprivation is not fully answered.* It is now thought, however, that the use of two-man teams will obviate in large part the hazards of acute sensory deprivation.52
In 1957, Clark and Graybiel found in their study of the