>>14125068Today I will remind them.
The life support system was greatly simplified since body cooling was accomplished by the simple and natural method of sweating. The suit was porous, and the sweat simply evaporated through the second skin. Tests of the suit in vacuum chambers showed no signs of excessive fluid loss, or freezing of the skin. They also demonstrated that, at such a scale, the skin withstood the tensile loads. Without the need for thermal control, the life support system became a tank of oxygen with pressure regulators and a carbon dioxide scrubber.
In the 1971 program ten successively refined prototypes of the suit were built, including 13 hours of wear by test subjects in vacuum chambers of up to 2 hours 45 minutes duration. The tests showed no significant problems in comparison to conventional suits. But whereas the energy cost of simple tasks in the Gemini or Apollo suits was typically 2.26 times that for a nude subject, in the SAS it was 1.64 times. And the mass of the suit, was half that of the Apollo suit.
But the tests also showed the major detailed technical challenges of completing development of such a suit. Most important was swelling/edema in parts of the body. To prevent blood pooling, the pressure across these regions needed to remain smooth. The most difficult areas to accomplish this in the crotch. There was also swelling of the hands, but this was reduced by using palm pads. This problem was seen as primarily mechanical in nature, and could be solved by further development, improved design, and use of new stretch materials.
