Weddings in space could be right around the corner, and experts figure the inevitable cosmic consummation will be just around the next corner.

The Japanese firm First Advantage and the U.S.-based private spaceflight firm Rocketplane Global, Inc., announced last week they will host weddings in space for about $2.3 million (240 million yen) apiece.

For all we know, sex in space has already taken place. But NASA officials aren't talking about that much.

Beyond space tourism as a platform for steamy shenanigans, space missions are the perfect petri dishes for close encounters, and this year NASA certainly has a busy flight schedule, with five missions planned. And more countries than ever are now venturing into space, with Japanese astronaut? Koichi Wakata slated to become Japan's first long-duration space flyer this year and China gearing up for its first spacewalk scheduled for October.

Things will get even more interesting with future long-duration missions envisioned for the moon, Mars and beyond.

"To say that astronauts are some superior beings who cannot have interests in any kind of sexual feelings for three years ? I just don't buy it," said Jason Kring of Embry-Riddle Aeronautical University in Florida. Kring also pointed out the possibly negative consequences of pregnancies in a microgravity environment.

"Are we going to sterilize our crew members before sending them to Mars?" said Kring, who studies the psychological effects of long-duration space missions.

Meanwhile, nobody claims to know whether "it" has happened already in space.

"We don't study sexuality in space, and we don't have any studies ongoing with that," said NASA spokesman Bill Jeffs of the Johnson Space Center in Houston. "If that's your specific topic, there's nothing to discuss," he added, referring to "sex in space."

In any case, science journalist Laura Woodmansee, who penned "Sex in Space" (CG Publishing Inc., 2006), predicts "honeymoons in space and out-of-this-world sex will be a reality within a decade."

Close encounters

Small groups tapped for lengthy space stints will likely experience related psychological effects. For instance, trivial annoyances could become divorce-level issues for couples. Other interactions are likely to be far more enjoyable.

Here on Earth, the closest analog to long-term isolation of groups in space is the South Pole, where about 200 researchers live year-round.

Last month, before six months of winter darkness descended over Antarctica's McMurdo Station, the research base received a delivery of about 16,500 condoms.

"There's an unspoken behavior there [at the polar base] where you take a spouse for the time you're there ? you have an exclusive relationship with someone," Kring told SPACE.com. "It's understood that when you leave, that relationship is over."

He added, "I don't know how it's going to work on a three-year mission to Mars."

Lawrence Palinkas, a professor of social work, anthropology and preventive medicine at UCLA, agreed.

"Certainly at polar research stations, there's sexual relations, sexual contact, between men and women," Palinkas said. "On a three-year mission to Mars, that's a possibility as well, although NASA in the past has tried to downplay the need for and the implications of sexual needs on a mission that long."

Coed crews

Up until the 1980s, NASA crews were all male. In 1983, Sally Ride became the first American woman in space aboard the shuttle Challenger. Missions now routinely include one or two women.

"[For] a true long-duration mission if we go to Mars or back to the moon, politically, I don't think you're going to see an all male or all 'American' crew," Kring said.

Politics aside, "research would suggest that a mixed crew of men and women would probably be best," Kring said. "And this goes back to the Antarctic research where it used to be the expeditions were all men."

Nonetheless, co-ed crews, like the all-male ones, will have hefty workloads and little play time.

"They're mission-oriented. They're very focused on the task at hand," said NASA spokesperson Nicole Cloutier-Lemasters of the Johnson Space Center.

Sexual frustration could ensue, however. "Human sexuality is a basic need and now you're trying to tell people, 'Hey for three years, you can't do that.' They're going to figure out a way to do it," Kring said.

If they do, they're on their own for now. Palinkas said there "is no official policy" at NASA regarding sex on space missions. "There really has been no research conducted on the area to know whether it [sex in space] would be a good thing or a bad thing," he said, "but it probably is inevitable."

How it works

Sex is about more than psychology and rules and mission plans, of course. And when you get down to it, the key to successful sex in space is about managing a microgravity environment.

In "Sex in Space," Woodmansee describes several positions that might work, ranging from the modified missionary position to seated with "interlocking Y legs."

Props also could come into play, including a shared elastic waistband or tethers to hold one partner to a stable structure, she writes.