"Some women, Commander Norton had decided long ago, should not be allowed aboard ship; weightlessness did things to their breasts that were too damn distracting. It was bad enough when they were motionless; but when they started to move, and sympathetic vibrations set in, it was more than any warm-blooded male should be asked to take. He was quite sure that at least one serious space accident had been caused by acute crew distraction, after the transit of a well-upholstered lady officer through the control cabin."
Arthur C Clarke,
Rendezvous with Rama
Kate Upton demonstrates his point beautifully (thanks to Goodstuff for finding this). A 9 month trip to mars would be never be boring with her.