This obscure little book by Stephen Baxter is a fast read and quite a bit of fun. Set in 1962 with a decent cast of youngsters, it also has Dr. No (the movie), the Beatles and the Cavern Club, and a Vulcan nuclear bomber. Humor in appropriate places and suspense in the rest lead to an exciting conclusion.

Target audience seems to be teenaged British readers, and I needed to look up some of the slang. Minor technical quibbles are easily overlooked in favor of the story. Would make a cracking good movie!