<>Survey Ship is one of Marion Zimmer Bradley's lesser known novels, and with good reason. It's far from her best work. I don't mean it's unreadable, but it could be a lot better. 

The survey ship is crewed by 3 men and 3 women, trained from a very early age to survey planets . They have spent almost their entire lives together, training for possible selection for this ship. And only 6 out of 40 are chosen.

This is not a book for those uncomfortable with sex scenes, which are somewhat plentiful. Combine that with the artwork in the edition I own, and it is definitely not for everyone. Not that the artwork goes too far, but it's not for the immature.