 What wasn't an issue their bodies were going through?
He had no stomach for mysteries, vast or trifling, and there were pressing things to think about at this time. Then he settled back and waited impatiently for the intruder who demanded his time without justifying it. He was with Armstrong on Mars during his Service days, did a good deal of the original mapping and surveying for the Colony there. “I want to make a Crossing at perihelion and I want to cross on the surface. That makes the Brightside of Mercury at perihelion the hottest place in the Solar System, with one single exception: the surface of the Sun itself. It was a real hell’s Crossing, but someday, I thought, somebody would cross it. The Twilight Lab, near the northern pole of Mercury, was the obvious jumping-off place. F. No permanent installation with a human crew could survive at either extreme. But with Mercury’s wobble, the twilight zone between Brightside and Darkside offers something closer to survival temperatures. Sanderson built the Lab up near the pole, where the zone is about five miles wide, so the temperature only varies 50 to 60 degrees with the libration. The Solar ’scope could take that much change and they’d get good clear observation of the Sun for about seventy out of the eighty-eight days it takes the planet to wheel around. The Major was counting on Sanderson knowing something about Mercury as well as the Sun when we camped at the Lab to make final preparations.
 malnutrition
 dehydration  malnutrition  headaches  irritation