"It's a very, very dry environment. We do have certain moisturizers that are approved, just to not be so flaky ... [but] there are always flakes of dead skin floating around -- on the vents, on the screens," says Coleman. The biggest culprit? Feet. Because they're floating around 24/7, calluses disapppear. "We come back with super soft, baby feet," she says. On the flipside, the tops of their feet take a beating. "We're always using our feet on handrails to stay in place and kind of 'perch' when we're watching TV," says Coleman.

"We're allowed to bring makeup, and I've brought it on every [mission] ... but I rarely use it," says Coleman. Plus, the process of finding products that are compatible with the environmental system -- the one responsible for cleaning the air and removing carbon dioxide -- is enough of a hassle. "We have a sort of 'girl's club' in the program and we leave things for each other [on ISS] -- things that are nicer to have: a nice comb, a belt, makeup, a moisturizer we really loved that didn't throw off the environment. It's so hard getting something up into space, it's not really worth it to bring your own."

Floating in the ISS gives your hair super strength that puts Biotin to shame. Coleman recalls being able to use a floating, single strand of hair to propel herself off a wall. Coleman didn't notice any difference in growth rate, but purposefully grew her hair out for her mission. "I really wanted to have my hair be a little bit long, because I wanted it to be clear that I was a woman in space -- not just an astronaut in a picture taken on the ground," says Coleman, who let her big, curly head of hair loose in space. "It was nice letting it have a little life of its own."

Also, pulling her hair back into a ponytail -- Coleman's preferred and practical style -- is a big no-no. In a weightless environment, hair elastics crank those annoying dents up 10 levels. "Your hair will be perpetually bent in one place," she says.

Considering the importance of the missions at hand, manis and pedis aren't on the itinerary -- oh, and the chemicals in nail polish, such as alcohol, poison the environment that circulates the ISS's air. That, too. But Coleman notes that both female and male astronauts pay extra attention to their nails in space. "Some of us, including the guys, paint our nails with Hard As Nails products to give them extra strength, because the space suit's gloves and the environment are pretty hard on your nails," says Coleman. In space, outside ISS, Coleman says the air pressure that pushes down is like a hammer on your nails.

To avoid the pain, keeping your nails extremely short is key, but clipping is no ordinary task in space. "Every little nail clipping will fly off and float around until it lands on a filter," says Coleman. To keep her trims discreet, Coleman's clips her nails next to vents that suck in air and filter it out. ("I do the same when I eat something with a lot crumbs," she says.) Easy enough, although Coleman says getting to your toenails is it's own beast. "Imagine trying to clip your toenails in a swimming pool," she says. "It's less about balance, like on earth, and more about keeping your foot up to your chest. I have to enlist someone to volunteer their back so I have somewhere to keep my foot somewhat still," says Coleman.

"Shaving really depends who you're with ..." Coleman begins cautiously. Imagine what a mission simply clipping your toenails is, and try to factor in all the moving parts that come with shaving your legs (flying suds and hair, anyone?). "I pretty much wore pants the entire time, so I didn't even bother." She also admits that down on earth, she usually turned to waxing to skip the constant shaving.

"Whenever there's a spacewalk, anyone who isn't doing the actual spacewalk has to be in the rescue ship for the entire day. Whenever my friend Sandy [astronaut Sandra Magnus] was up there all by herself while her two crewmates were out, she'd refer to those shifts as her own little spa day -- that's when she'd take the time to shave," says Coleman.

While an earthling's sleep enemy might be tossing and turning at night or the appearance of sunlight, astronauts are more concerned about floating around the cabin as they snooze -- the zero-g equivalent of sleepwalking.

"Everyone has their own little cabin for sleeping, where you can doze off with your back tacked to the wall. Or you can slither into a blanket with arm holes, so you can type on your computer or read while you're "in bed"." (Snuggies in space!)

The most basic element of sleeping -- horizontal -- is one of the simple pleasures astronauts miss most, says Coleman. "Some people miss having their heads on a pillow -- just the feeling of having something there," she says. Those who pine for pillows have to settle for straps that dock their head to a wall, but the one thing that's relatively the same down on earth? Astronauts are given eight hours to sleep -- although they rarely log in the full eight thanks to, well, everything happening up there.