“I do think there is a time when sexuality in space is going to have to be addressed,” said Paul Root Wolpe, the Director of Emory University’s Center for Ethics and a senior bioethicist at NASA. “I do not know if NASA has an official policy on sex in space, [but] there will be a time when NASA needs to make some policies or understandings about those kinds of relationships. There is a point where the length of time [on a mission] becomes part of the question of whether or not it’s fair to deprive people of this aspect of being human. I’m just not sure it’s time yet.”
Aside from the lack of urgent scientific reasons to really test human libido and sexual behavior in orbit, the simple fact of the matter is that body-to-body docking in microgravity is probably not as orgasmic as we might imagine it to be. In the first place, there are significant logistical difficulties in orchestrating the deed, and this alone, Wolpe suggested, might be reason enough to dissuade astronauts from unofficial experimentation.
“A lot of people think that sex in microgravity will be great because by losing gravity you can move in ways you can’t terrestrially. The [scientists] who’ve thought about this aren’t so sure about that at all,” he said. “One of the things that gravity helps us do is stay together, so sex in microgravity might actually be more difficult because you’re going to have to make sure that you’re always holding each other so you don’t drift apart. It might be a lot more challenging and a lot less fulfilling than most people think.”
Even if the logistical difficulties of space sex can be settled, there’s still the problem that microgravity makes sex, well, significantly less sexy.
Astronauts tend to sweat more in space, and decreased blood pressure could make it more difficult for males to hold up their end of the mission. As for the female side of things, the jury is still out on whether microgravity is a bane or a boon to boobs.
http://motherboard.vice.com/read/sex-in-space