Port Laribee with its score of Nisson huts, sealed against the lifeless atmosphere, the red dust and the cold, was a shabby piece of Earth dropped onto Mars. There, Dave Kort was the first wilderness tramp to be remembered. In warm seasons he'd plod into Port Laribee, burdened by a pack that only the two-fifths-of-terrestrial gravity put within the range of human muscles. He was a great, craggy old man, incredibly grimed and browned, his frostbites bandaged with dry Martian leaves tied on with t