"Yeah," somebody answers. "And who is that guy walking through your front door without knocking while you're away?" Sometimes it seems that close. On Mars, Earth is just another bright spot in the black night sky; so far away that the first reaction is one of terrible despair, the overpowering conviction that in all that vast hostility a man will nevermore see home; nor know again the balmy twilight of soft, moist summer; nor feel the arms of love. Explorers had not lied. Nothing, anywhere, could be more worthless to man than the planet Mars. Worthless, except for the unique purpose which had brought us there. We dug in beneath the surface. Now surely, again, everyone has seen enough of the documentaries that it is unnecessary to show us digging out our living quarters and laboratories beneath that merciless plain. We used the displaced powdered rock to form a crude cement, not long lasting but adequate for the time we would be there. With it, we surfaced over our living area. This was not so much to provide a landing field, since most of our journeying would be in individual jet powered spacesuits; but to help insure against any leakage of air if our inner seals cracked. To help seal out the killing radiation we intended to let loose--that, too. We erected Come-to-me towers at each elevator which would lower spacesuited men to lower levels where they could go through locks to reach their quarters. One Come-to-me tower for each half dozen men, tuned to the power source of their suits, to bring each man safely back, as truly as a homing pigeon, to guarantee against becoming lost on that hostile planet; and, in emergency, should one arise, to see that no panic mob ganged up at one lock and died waiting there for entrance to safety while other locks remained idle--the human way of doing things under stress. * * * * * We had to finish all that in the first few weeks before any nuclear tests could be started. Anybody whose notions of science are derived from white-frocked actors in television commercials hasn't the vaguest idea of how much back breaking physical work at the common labor level a genuine scientist has to do. There was some emotional relief once we had dug in and sealed out the awful desolation of an uncaring universe. (This is the hardest part of reconciling oneself to the science attitude. More comforting to believe even that the universe is hostile than to admit that it simply doesn't care about man, one way or another.) In our sealed quarters we might briefly imagine ourselves working in an air conditioned laboratory back home. It helped. It certainly helped.