SPACE SEX ISSUES

There are so many things to consider when planning the extended space exploration missions of the future:

"With the prospect of a very long-term mission, it's hard to ignore the question of sexuality," says Lawrence Palinkas, a medical anthropologist at the University of Southern California in Los Angeles, an author of the report. It reviewed NASA's plans for research to keep astronauts safe and healthy in space – but the plans make no mention of sexual issues in spaceflight.

Palinkas says long-term space missions may be similar to extended periods in the isolated and confined environments of Antarctic research stations. He says crews in those stations often pair up in "bachelor marriages" that last the length of their stay – or less. "If there are instances of sexual conflict or infidelity, that may lead to a breakdown in crew functioning," he told New Scientist.

"Breakups can lead to violence and all kinds of things," agrees Carol Rinkleib Ellison, a psychologist specialising in sexuality and intimacy based in Oakland, California, US, who was not part of the NAS panel. "People are very primitive in their emotions around partnering and sex."

On the other hand, masturbation and sex would keep astronauts amused on a 30 month round trip to Mars.