The Manhigh sealed cabin atmosphere.

W H E N the Manhigh capsule system was being designed in the fall of 1955, the pr imary objective was a maximum performance system of minimum weight that could lift a man into a space equivalent environment for twenty-four hours. This objective 'had to be met safely and supply an answer to what the man could :do if any specific componem failed. Beyond this, an effort was made to provide him with as comfortable a "shirt sleeve" environment as possible. The 1pressure and atmosp,heric composition of a sealed cabin designed for a space mission must be selected in terms of the peculiar needs of that specific mission. This paper shows how the atmosphere used on the Manhigh program was tailored to fit the needs of that flight. Many of the eonsiderations apply directly to. satellite missions and other 'high altitude balloon flights. The sealed cabin atmosphere of the