Oh! Anne McCaffrey's Brainship series is a treat to read!
That's a good idea! Somewhere on another forum someone was asking about YA SF and this would've been a good suggestion. There's a great deal of fantasy for kids, but much less good science fiction.
On a related note, though, I'd caution about Anne McCaffrey's Dragonriders of Pern series, some of which turn up listed as YA. These are great books and kids will like them, but because of the reproductive processes of the dragons, I'd avoid 'em until middle school age or pre-read each book individually.