What must the pioneers do in order to survive on the moon in the story, Escape the Morning?

The pioneers, in order to survive, must pay careful attention to their environment, never allowing panic to make them break the rules that help safeguard their lives. When Mark takes his turtle, a slow vehicle, out to rescue Kamolondo, he follows a prescribed path that has been outlined by glowing markers. When he races towards safety with Kamolondo against the coming of dawn, he cooly keeps control of his judgment, following the lit path even though a direct route home would be shorter: "To strike directly across this shadowland, away from the markers, was to make death certain."