Packing for Mars
Being cooped up in a box in close proximity to a few companions for months on end is stressful enough. Then there's Zero G - fun for a while, but over the long term not likely to be good for your health. If you can take that then there's the high G experience on take off and landing. If something goes wrong, what are the chances of escape? Even everyday things can be a problem - keeping clean, having a healthy diet and going to the toilet. Is sex in space a possibility?
One thing which Roach highlights is the large number of simulations of living in space which have been undertaken - every procedure carried out in space is first simulated on earth, and some people have spend months lying down to simulate the health effects of weightlessness.
If you're looking for a serious look at the problems of space travel then this book might not be for you, as it does play for laughs quite a bit, and often becomes rather scatological. But it does have answers to the sorts of questions which you've probably wondered about, and provides an excellent way of amusing yourself for a few hours.