You might not recognize any of this crew from Flight of Exiles (1972) as it's some years and a whole test tube generation later, but their situation will be instantly recognizable to space travel initiates. A primitive priestess whose ceremonial robe is an old electric blanket. . . a set of commandments that is really the tape-recorded last words of Jerlet, before he went upstairs to a healthier, zero-gravity environment. . . superstitious kids who don't realize that their "world" is really a robot-controlled megarocket. One of them, Linc, does realize and learns to fix the machines in time for a final course 'correction and a happy landing on the earthlike planet Beryl. Despite some dismal gimmickry (salvation is effected at the last minute by a matter transfer machine, the ship has been supplied with a zillion year stock of o.j. and soyburgers) and thin personalities (females seem particularly weak-willed, even the wily priestess Magda), Linc's lonely voice of rationality and love of tinkering keep this humming smoothly. Programmed escape.