 Why is Rikud oddly satisfied about Crifer's limp foot?
When nobody aboard ship remembers where it's going, how can they tell when it has arrived? Every day for a week now, Rikud had come to the viewport to watch the great changeless sweep of space. But ever since the engines somewhere in the rear of the world had changed their tone, from the steady whining Rikud had heard all twenty-five years of his life, to the sullen roar that came to his ears now, the feelings had grown. The stars—it was a meaningless concept to Rikud, but that was what everyone called the bright pinpoints of light on the black backdrop in the viewport—were not apparent in the speckled profusion Rikud had always known. Instead, there was more of the blackness, and one very bright star set apart by itself in the middle of the viewport. Someone was clomping up the companionway behind Rikud. Rikud knew he should be exercising now, or bathing in the rays of the health-lamps. Chuls' reminder fostered uneasiness. Often Rikud had dreamed of the time he would be thirty and a father. But it came again, and each time it left him with a feeling he could not explain. Rikud knew that something which he could not explain had entered the elder man's head for a moment, but it had departed almost before Chuls knew of its existence. "I'll go with you," Rikud told him. Chuls stripped himself and selected the space under a vacant tube. Rikud, for his part, wanted to get back to the viewport and watch the one new bright star. Rikud muttered to himself and undressed. There was a strange thought, and Rikud's brain whirled once more down the tortuous course of half-formed questions and unsatisfactory answers. But something soft had cushioned the impact—something which had come into being just for the moment and then abruptly passed into non-being again, something which was as impalpable as air. Rikud had been stopped in this action, although there was no real authority to stop him.
 It's evidence that imperfections still exist, and validates Rikud's feelings.
 It's new and interesting. Rikud is tired of the regular.  It means that people can hurt, which Rikud has an interest in.  He dislikes Crifer, and enjoys the fact that he is stuck with an anomaly.  It's evidence that imperfections still exist, and validates Rikud's feelings.