Orbit Unlimited (Pyramid Books, New York, 1961);
New America (TOR Books, New York, 1982);
The Queen Of Air And Darkness and other stories (NEL Books, London, 1977).
Orbit Unlimited collects four stories set respectively on Earth, in space, in Rustum orbit and on Rustum. The fourth story describes life on the plateau and a rescue expedition to the lowland. This concluding story, and thus also the book, has a positive ending:
a lost child is rescued;
his rescuers, the child's father and another man, are heroes;
the father, a strict puritan, has resolved some personal issues during the rescue;
the mayor had blackmailed the second man to accompany the father in order to counteract the colonists' tendency towards isolated agricultural selfishness - public duties performed freely from a sense of responsibility will minimise the need for coercive laws as the colony grows;
the boy, an exogene formerly bullied by his peers, is now a hero to them;
more importantly, he is a rare individual who can live comfortably in the high air pressure at sea level, thus he and his descendants will colonise the rest of the planet.
This positive ending is well expressed by the concluding sentences as the blackmailed but now happy rescuer recuperates:
"Svoboda didn't return to his book at once. He lay for a while gazing out the window, toward the horizon where the snowpeaks of Hercules upheld the sky." (p. 158)
I am currently rereading New America but can comment now that the title and the blurb are misleading. The latter refers to "...freedom-minded Jeffersonians..." whereas the book features not Jeffersonians in a place called New America but Constitutionalists on a plateau called High America. This book, a sequel to Orbit Unlimited, continues the story of Rustum and introduces other extrasolar colonies.