Men into Space by Murray Leinster — Read

(There was high adventure on the moon when it was first colonized. Men faced various ways of dying -- all of them unpleasant -- and found that simply staying alive was a great satisfaction and a full-time occupation. Because of this spirit -- which is that of true adventure -- there came to be bases where hydroponic gardens freshened the air and men took continued living as a matter of course. This, obviously, was not adventure. So problems arose. Men began to be moved by other motives than the zest they'd known at first. But there were still a great many ways of getting killed on the moon. So there came a time when Colonel Ed McCauley had to insist that certain men under his command put first things first, as adventurers do, and not act for the gratification of their problem personalities.)

Traveling at moon gait, which is the standard travel pace on Earth's big moon, McCauley had ten of the last twenty miles behind him when he saw the sledge trail in the dust. He frowned at it and looked over to the west. He saw Earth, blue-green and glamorous, hanging as usual in the lunar sky just above the edges of the ring mountains. But Earth was always just there. He squinted at the sun through the faceplate of his helmet. It was a trifle over ten degrees above the horizon and it moved across the black, star-speckled sky at half a degree per hour. In twenty hours, then, lunar night would fall. And here was the sledge track that said that the relay unit for Repeater Two, carrying word to and from Farside and the rest of the human race, had passed this way en route to be set up; but the lack of returning footprints said that the men with it had not come back.