Unknown Planet by Jean Ure
The Spaceship Sea Queen is part of a fleet searching for a new world. On board are 50 children. Their own planet, Aqua, is dying and can no longer support them. Then the spaceship crashlands on an unknown planet, which young readers, however, may find strangely familiar. Jean Ure's other books include "Plague 99" (1991 Lancashire Children's Book of the Year), "A Proper Little Nooryeff", "Wizard in the Woods", 'Wizard in Wonderland" and "Captain Cranko and the Crybaby".