Published originally in Astounding as ‘Universe’ and ‘Common Sense’ this early work by Heinlein may be also one of the first ‘generation ship’ novels of the genre, but by no means the best.
Presumably aimed at a juvenile readership it is centred around a young man called Hugh Hoyland, an apprentice scientist in the world of ‘The Ship’. Their sacred writings are manuals; works of physics and Ship’s records. Fiction is considered to be ancient records of real events. The ship’s inhabitants believe the Ship to be the Universe and that nothing can exist beyond its walls.
One day Hugh is captured by Muties (mutants who live in the zero-gravity area near the hub of the ship), taken to see the control room, and begins to realise that everything his people believe is a lie.
Hugh manages to eventually unite the crew and the muties (which may also be a reference to Mutineers, since their current state of existence is due to a long-ago mutiny) and restarts the ship’s drive in order to complete the journey the ship set out on.
The boss of the mutie gang, Joe Jim may be or may not have been an unconscious inspiration for Zaphod Beedlebrox of ‘the Hitchhiker’s Guide to The Galaxy’ since he has two heads, one being Jim, one being Joe. The argue incessantly until they reach some kind of consensus.
Sadly, there is a rushed and rather improbable ending, following a somewhat unlikely series of events. Hugh manages to learn how to launch a landing craft from the ship only to discover that they are within spitting distance of a life-bearing world, and then safely lands the craft.
Most of the book has Heinlein’s trademark amiable readability but the denouement is too rushed and contrived and no doubt causes even Heinlein fundamentalists to raise an eyebrow or two at such convenient coincidences.