Ross Montgomery started writing stories as a teenager, when he should have been doing homework. After graduating, he decided to channel these skills into teaching at a primary school.

Author of Alex, the Dog and the Unopenable Door and The Tornado Chasers, Ross has been shortlisted for the Costa Book Award and nominated for the Branford Boase Award. He lives in Brixton, London. Space Tortoise is his second picture book, following The Building Boy.

David Litchfield first started to draw when he was very young, creating comics for his older brother and sister. Since then his work has appeared in magazines, newspapers, books and on T-shirts. David's first picture book The Bear and the Piano won the Waterstones Children's Book Prize. He lives in Bedfordshire.