The mystery is a good one, and Dashiell's use of available clues realistic. The interactions of the space crew go against protocol in some instances, but are probably very true to life of any group of people forced to spend extended time together.
Gibbs is always a pleasure to read. His prose is facile and funny, and my students like his work every bit as much as I do. I love the fact that his series tend to be short enough that all of the books get read (something which just doesn't happen if a series is over about 4 books long), and that the publisher has kept the same style of covers on all of the books. Spaced Out is a great choice for readers who like mysteries, science fiction, or just an amusing read!