The International Space Station – which is coming up on a decade of continuous human habitation – is a celebrated success in our species' quest to learn to live in space. Yet life in orbit has its serious trials, and mishaps along the way have proven just how much we still have to learn about being a spacefaring civilization.
10. Fingernails fall off
The spacesuit gloves astronauts wear while working outside the station during spacewalks have proven to be hazardous to their health.
A recent study found that about 10 percent of astronauts are victims of "fingernail trauma" from gloves, with a number of them losing a fingernail entirely because the glove pinched their fingers and reduced circulation.
Typically, the damage is worse the larger an astronaut's hand is. Maybe NASA should look for petite spaceflyers.
9. Weightless worries
Weightless living can have some pretty odd consequences without even going outside. Take, for example, the attack of the flying wasabi.
In March 2007 astronaut Sunita Williams was trying to squeeze some of the spicy green condiment onto her makeshift space sushi, when a squirt got loose, ultimately splattering the walls with wasabi and hiding stray droplets around the module.
It took a while to get the wasabi smell out after it had flown all over the place, Williams said at the time. And she had to forgo wasabi on future space meals, saying it was just "too dangerous."
8. Rough ride
While floating on the space station can be fun, getting to and from it can be a rough ride. Trips on the Russian Soyuz spacecraft, in particular, reportedly pack quite a punch of G forces.
"I've heard it described as a train wreck followed by a car crash followed by falling off your bike," NASA astronaut Tracy Caldwell Dyson said recently before she flew home from the station on one herself.
After she had experienced the trip, she said the rumors were dead on.
"It certainly didn't disappoint," Caldwell Dyson told SPACE.com after her return. "All the bangs, bells, whistles and sensations were there. The magnitudes of some things were a little surprising, but for the most part it was a pretty exciting ride."
7. Space diet of baby food
Though it's not just Tang and freeze-dried ice cream these days, food in space still leaves something to be desired.
Fresh fruit and vegetables are scarce, for example, and ground staples like bread are impractical because they leave crumbs, which in microgravity fly around everywhere instead of settling on the floor, and become a disaster to clean up. (Instead astronauts favor tortillas, which create fewer crumbs).
And astronauts tend to get sick of the same roster of re-heatable meals rotated on an eight-day schedule.
In the winter of 2004, however, an unmanned cargo ship due to deliver fresh food and supplies to the space station was delayed. In response, the crewmembers onboard – Expedition 10 commander Leroy Chiao of NASA and flight engineer Salizhan Sharipov of Russia – had to ration their meals.
The two ended up cutting their regular food consumption in half to conserve supplies, then making up for the lost calories by eating abundant desserts and candies. "It wasn't an unhealthy diet, but it wasn't an ideal diet either," Chiao said at the time.
6. Cramped quarters
While the station has grown considerably over the 10 years it's been permanently inhabited, many spaces are still a tight squeeze. And for the last year and a half, the normal crew size aboard the orbiting lab have been six, meaning what space there is has been shared by more bodies.
Sleeping can be particularly cramped inside an astronaut's "crew quarters" – essentially an alcove the size of a phone booth – and there are other hazards of catching some Zzz's in a free floating sleeping bag.
"During the night while you're sleeping, you might start drifting and end up somewhere you didn't intend to be in the first place," Canadian astronaut Julie Payette said in 2009.
Yet overall, the coziness of slumbering without gravity's incessant pull makes sleeping in space rather comfy, Payette said.
5. Hygiene hiccups
The lack of showers in space often puts a serious damper on the experience.
Microgravity makes it impossible to have a normal shower where water falls from a stream and falls docilely into a drain. Instead, astronauts on the International Space Station use a squirt gun that shoots out water and a wash cloth. They also have a special rinse-less shampoo to keep their hair clean.
"We wash like we would if we were on an expedition or a camping trip or something," Payette explained. "It works."
Still, who wants to keep that up for six months? Especially with the aforementioned tight living quarters!
4. Toilet troubles
One of the peskiest recurring problems on the station is the toilet situation.
There are two toilets on the space station – one in the Russian segment, and one in the United States modules. But both have been balky, breaking and requiring on-orbit plumbing jobs to get them working again.
Then there's the issue of what happens to the waste water – as of May 2009, urine is recycled into clean drinking water, and is also recycled into water for bathing and food preparation.
"It's sort of one of those horrible and fascinating kind of things. It's like, 'You're going to drink urine?'"said astronaut Sandra Magnus, who was living on the station when the urine recycling system was installed. "We're not, we're drinking processed water that started as urine."
3. Creaky bones
Beyond the daily nuisances, astronauts have to deal with serious health consequences from their time in orbit. One of the most significant of these is the effect on their bones.
A recent study found that astronauts' bone strength dips by at least 14 percent during a half-year stay in space. Other research indicates that an astronaut's bone mineral density can decrease by between 0.4 percent and 1.8 percent each month they are on the station, leading to greater risks of fractures and osteoporosis later in life.
While there is no complete fix for this problem, astronauts are diligent about bone-strengthening exercises while they're on the station, and undergo extensive rehabilitation once they're back on the ground to try to avoid possessing the bones of a 90-year-old.
2. Losing your lunch
Space sickness, too, can affect the best of 'em.
Acclimatizing to life in zero gravity, especially since no simulator can reproduce microgravity on the ground, takes time. It's not uncommon for astronauts to lose their lunch after liftoff before they even reach the space station.
And, to make matters worse, spewing chunks in space creates rather more of a mess than it would on Earth, since projectile vomit doesn't project toward the ground.
1. The loneliest number
Perhaps the hardest part of life in space is the feeling of isolation astronauts can get when they spend half a year removed from the whole planet, especially their friends and family. While astronauts can combat the loneliness by bonding with crewmates and making frequent calls home, they sometimes have to miss major life events back on Earth.
In December 2007, NASA astronaut Daniel Tani's mother died in a car accident while he was living on the space station. Tani had to grieve from more than 200 miles away in orbit, until he came back to Earth about two months later.
And in 2004, NASA astronaut Michael Fincke was forced to miss the birth of his second child, when his wife gave birth to daughter Tarali while he was serving a long-duration mission during the station's Expedition 9. He was able to meet his daughter four months later when he finally landed.
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