For those who weren't aware that reptiles had been orbiting the Earth, the Russian Federal Space Agency, Roscosmos, launched its Foton-M4 satellite from its cosmodrome in Kazakhstan on July 19 in order to conduct experiments on life in space — the sex life of geckos in space, to be specific.
A male Mauritius ornate day gecko and five females of the same species were packed into the satellite along with cameras to film their copulation (without their consent, it must be noted; gecko-human communication is still primitive). Experiments were also in place for fruit flies, microbes, and mushrooms, but it was the gecko study, called "Gecko F4," that had Russian scientists waiting with bated breath for the return of Foton-M4.
Shortly after launch, Roscosmos lost contact with the satellite, leading some to wonder whether the errant geckos' descendants would one day return to Earth as an evolved reptilian super-race. These fears (or hopes?) were moot after the geckos met a much more mundane fate: They returned to Earth dead, apparently due to a life-support system malfunction, without having produced any eggs. It's still unclear if the reptiles even had sex; scientists have yet to report back on their flight footage findings. (The fruit flies on board were more successful than the geckos: They not only survived, but also reproduced.)
You may be wondering why the biologists running the gecko experiment went to so much trouble. It actually wasn't about the geckos — they were looking for clues regarding the effect of space conditions on human fertility. As of now, we have very little idea of the consequences of long-term exposure to microgravity on our reproductive organs. Considering that future space voyages might take years and even span generations, the scientific community is already interested in how human copulation and reproduction in space would work.
There are some obvious challenges. While we've received firsthand reports of astronaut masturbation, as far as we know, no astronauts have actually had sex with one another while in space (science writer Mary Roach has enthusiastically debunked the conspiracy theory that the U.S. and Russia conducted secret sex-in-space experiments). It's pretty clear, though, that erections in space are a lot harder than on earth — or rather the opposite. In microgravity, blood doesn't pool downward, but rather around the head and chest — not in a penis or clitoris. Lack of gravity would also make it difficult to stay adjacent to your sexual partner; an enthusiastic thrust could launch him or her to the other end of your vessel, though this problem could be addressed by creative tethering (bondage could take on a whole new role).
Another turn-off: Astronauts sweat. A lot. Not to say a little sweat ever hurt anyone, but we're talking so much perspiration that the slipperiness might actually make sex difficult. As for human reproduction in space, scientists don't yet know how microgravity might affect cellular development in humans, but early evidence of its adverse effects on plant cells is anything but encouraging.
For now, we may be better off watching zero-gravity sex than having it, and yes, that porn exists: To film a sex scene in the adult flick The Uranus Experiment: Part Two, actors and crew flew by plane to 11,000 feet and then did a steep dive while the actors somehow managed to have a few seconds of intercourse and the crew managed to capture it on film. Real space sex, it seems, would be a lot less glamorous. When you imagine sweating so much it's as though you bathed in lube, then attempting to have sex while you and/or your partner struggles to maintain an erection and avoid inadvertently sending each other flying across the room, you may feel grateful for your earthbound love life.