I keep hearing about the "sudden" interest in space sex . It's not sudden. It's not new. Science fiction authors discussed and proposed many creative solutions to the various problems decades ago. It's a solved game. Since humans have been visiting space for decades, some of them for fairly long trips, and humans fuck, it is far more likely than not that some people have already fucked in space. More impressive than accomplishing this is that anyone who has, so far has kept their mouth shut. Given the high incentive for silence -- it's a competitive program, and annoying the bosses could get people kicked out -- this is plausible. For starters, ionizing radiation could interfere with sexual reproduction by altering the DNA of sperm cells, egg cells, and even human embryos (though one study suggested that mammal embryos can develop normally in space) . The real problem there is statistical. The radiation raises the chance of malfunctions. It's not that you can't get some viable births. It's that you get fewer healthy births and a lot more problems, and those problems tend to compound over time. The best bets are things we don't have the tech for yet: energized personal shielding, gengineering to resist radiation, and doing all reproduction with imported gametes and artificial wombs in heavily shielded facilities. The nastier method that we could already use: combine gametes in a lab, and examine the results to discard anything with obvious flaws. Right now, humans are squeamish about wasting human embryos, but if you need 10 or 20 to get one viable, you do what you have to. It just has some bad emotional effects on people. I don't really recommend it. Moreover, microgravity could make sex both difficult and messy — a big problem in a setting where cleanliness is paramount . Solved game. Anything from sharing a sleep sack to bungee bands to wedging yourself into a snug corner will solve the microgravity problem. Numerous solutions have been proposed, many quite workable. But some people like freewheeling, that is, sex without any attachment point(s). If you're concerned about thrust physics, remember not all sex involves thrusting; consider the 69. As for mess, a condom contains most of it, and the rest is no worse than the flying sweat drops generated by exercise necessary to maintain muscle tone in space. You mop the air with a towel or a handvac same like always. I will further point out that sex is self-motivating exercise so you don't have to nag people to do their hours. Also, the whole scenario is much less bothersome than a shower door or toilet containment failure when you're jaunting down a tube chasing 5 gallons of water with a towel. Thinking further, I admit that I have not seen a recommendation on how to deal with female squirting, which can be copious and surprisingly projectile. Likely the best way to deal with this would be to keep that area covered as much as possible with something absorbent (like cloth) or at least wipeable (like a sex partner). Space habitats are also cramped, remote, and not always private, making sexual needs hard to satisfy . 1) Privacy was only invented when people wanted civilization, and for millennia it consisted of "don't look at other people's hearths." In much of the world, where people still live 12 to a room, it still does. This has not stopped them from making billions of humans. That's before we throw in the people without a nudity taboo and the exhibitionists. Festival babies are a thing. 2) Consider how many humans have been conceived in Volkswagons, pup tents, and paint lockers. Clearly this isn't an effective limitation either. Thinking even farther into the future, small settlements with limited intimate partners will undoubtedly breed stress, conflicts, and even sexual harrassment or assault . Or you could just take along some canned gametes like sensible people to minimize inbreeding and competition for reproductive partners. Competition for sex and attention will likely be solved in the same ways people have solved it in similar situations planetside. Options include: * Send only married couples. They might break up, but at least you've got a good chance of stability. * Include professional providers of sex and attention. This has been quite common in some cultures. * Send single-sex crews. This tends to result in homosexual activity, but hasn't stopped this becoming a popular approach. * Offer sex dolls. We have much better ones now, so this is likely to improve in efficacy. * If I were worried about this, I'd send aromantic asexuals, who don't have sex problems with each other. The further people are from Earth and the longer they are in space, the more likely that sexual and relationship-related problems will arise, Dubé and his colleagues write . Which is really not much different from all the previous examples of long expeditions, sailing ships, remote outposts, and so forth throughout history in terms of the interpersonal and sexual dynamics. Presumably humans will continue doing what they've done in those situations, which is masturbate, help each other out, or move hell and high water to get some potential mates imported. There are lots of old SF stories about all of this. It's not like the activities are difficult to predict. They make the case for researching solutions to these risks right away. LOL the time to research that was decades ago. I'd say it's a good thing we had SF writers to tackle that topic, except everyone seems to have forgotten about them. For fucksake, I ran the Midnight Sex Panel at cons for years, and we usually talked about space sex at some point. At least once, I had a fellow panelist who was both involved in space-related activity and polyamorous, although I didn't hear about those points until after the panel. If NASA wants to know about space sex, their nerds -- I assume they're still hiring nerds -- should just open up about it. This effort may also include preliminary planning for delivering babies in space and treating any sex-related health issues. Now childbirth in space is a real hazard. It generates lots of effluvia even when it goes well. But the lack of gravity is a big problem. It's used in everything from influencing birth time to getting the baby out to clearing the baby's lungs enough to breathe. I wouldn't recommend it unless you can generate at least some significant gravity, which currently we can only do with spin. Not a great situation. Nor is surgery a good solution since that is even messier and harder to do in space; you really can't see what you're doing when the blood won't pool. The third is engineering sexual technologies like toys or robots that permit clean and satisfying sexual experiences . I should like to point out that while using sex toys is simple, cleaning them in space really is not. I strongly recommend the "removable vagina" option for sex dolls, preferably silicone so you can simply throw the thing in an automatic washer. Trying to clean a fixed-vagina sex doll in space would be a nightmare; the removable option exists because the fixed option is a giant nuisance even with gravity. Admittedly, NASA probably hasn't discussed removable vaginas. I recommend that, in addition to reading classic SF, they also hire a expert sex educator who won't be squeamish about discussing the hardcore details. *ponder* And get a disabled person with an active sex life, you won't find a better problem-solver than that. A sex worker who caters to disabled clients would also be a great asset. Gosh, now I'm wondering if any of my escaped Chinese sexbots would like to be an astronaut. They'd be enormously popular, and Terramagne-NASA has an intensely diverse hiring pattern already, a lot of their robotics astronauts are disabled.