Authentic Science Fiction Monthly No. 72 — page 88: what you’re looking at

Machine-transcribed from the original scan — historical spelling and the odd misread are preserved.

AUTHENTIC SCIENCE FICTION human body, is quite another problem. A man generates 150 watts of heat and, normally, he gets rid of it by convection, conduction and radiation. In space he won’t be able to do that. A space suit must do more than provide pressure and air; it must provide pro- tection from external forces, the sun and space itself. Of the two, the sun is the thing to worry about. Unshielded by the atmosphere, solar radia- tion is strong enough to raise the day-side temperature of the Moon to that of boiling water. A man, working in a space suit on say a space station, is going to receive the sunlight directly on his suit and that suit is going to get hot. True, if he were in shadow, say that of the Earth or on the night-side of the Moon, he would radiate that heat away, but unfortunately for him, he carries his own heat engine with him, him- self. To protect the wearer against direct sunlight, the suit must be of non-conduc- tive material—remember he is wearing it close to his skin. 87 But you can’t have a material conductive one way and not the other. If the suit keeps heat out, then it must also keep heat in, and heat will be the one thing the spaceman wants to get rid of. A compromise can be reached by having the suit material conductive enough so that some heat from the wearer can be radiated away and silvered so as to reflect most of the heat received from outside. The trouble with that is that a bright surface radiates less than a dark one. A dark one, on the other hand, absorbs more radiation. The silvered suit is the lesser of two evils; we are trying to keep our space- man cool, not roast him alive. A healthy man can with- stand a great deal of heat because he has his own built- in cooling system. He gets hot, he perspires, air evapor- ates the perspiration and thus cools him down. It is on record that a man has ac- tually stood in a_baker’s oven and watched roasting meat without harm, and in the equatorial regions high comiclooks.corn