 What would've happened if Captain Llud tried to turn around and change course from Earth?
In the last hours the star ahead had grown brighter by many magnitudes, and had changed its color from a dazzling blue through white to the normal yellow, of a GO sun. That was the Doppler effect as the star's radial velocity changed relative to the Quest III , as for forty hours the ship had decelerated. At the voyage's beginning eighty per cent of the fifteen-hundred-foot cylinder had been engines and fuel; but as the immense stores were spent and the holds became radioactively safe, the crew had spread out from its original cramped quarters. Eyes lifted from the vision screens to interrogate Knof Llud; he met them with an impassive countenance, and announced quietly, "We've sighted Earth." Earth's still there." He said, with a touch of tolerant amusement, "What did you think might have happened to Earth? It won't be the same world we left, the world we knew and fitted in...." He had already set up on the calculator a course that would carry them to Earth. Llud nodded curt approval, remarking, "Probably we'll be intercepted before we get that far." And we don't know what changes have taken place on Earth. From his private office-cabin, he sent a message to Chief Astronomer Zost Relyul to notify him as soon as Earth's surface features became clear; then he sat idle, alone with his thoughts. The ship's automatic mechanisms had scant need of tending; Knof Llud found himself wishing that he could find some back-breaking task for everyone on board, himself included, to fill up the hours that remained. Now the last fuel compartment was almost empty and Captain Knof Llud felt tired and old. Perhaps, he thought, he was feeling the weight of his nine hundred Earth years—though physically he was only forty now, ten years older than when the voyage had begun. That was the foreshortening along the time axis of a space ship approaching the speed of light. It was one he had made shortly after leaving Procyon, end of the first leg of the trip. "One light-day out from Procyon, the thirty-third day by ship's time since leaving Earth. "Our visit to Procyon drew a blank. "Our hopes were dashed—and I think all of us, even remembering the Centaurus Expedition's failure, hoped more than we cared to admit. If Procyon had possessed a habitable planet, we could have returned after an absence of not much over twenty years Earth time.
 They probably would've been shot at and the passengers would've died eventually with low resources.
 They probably would've been shot at and the passengers would've died eventually with low resources.  They would've tricked one of the ships into housing all of the passengers and flying home on that ship instead of the Quest III ship.  They would've been left alone by the Earthen ships and accepted once they discussed matters some more.  The Earthen ships would've trapped and invaded the Quest III ship and held the passengers hostage.