This award is named after Hal Clement, the pen name of Harry Stubbs, who is a well known science fiction writer and science teacher. He helps children's science fiction programming wherever he goes and is an all-round nice guy. The award is for science fiction books of grades 6-12 that have a young adult protagonist. The science should be as correct as possible, but still a good story.
I've read Needle and Mission of Gravity. The Younger Son has read several more than that. When we discovered him we started picking up books by him just to have on the shelf. Owning unread books by trusted authors is such a comfort.