Susan Helms had already been to space four times before she set foot on the International Space Station. But those visits had been on the shuttle, experiences she likens to camping during a diabolically crammed business trip. Schedules were so packed that even bathroom breaks could be in question.
The space station, by contrast, was like a real home, says Helms, MS '85. In fact, for more than four months it was her only home. She'd given up her apartment, cut up her credit cards and put her belongings in storage before launching.
"It was very freeing psychologically to have nothing on Earth to worry about," she says.
Helms is one of 140 Americans who have called ISS home, typically for stays of about five months, since it began lapping Earth every 90 minutes nearly two decades ago. In contrast to the second-by-second demands of the shuttle, which took hold each morning with a wake-up blast of music, the space station offers some of the independence of real life. You might even hit the snooze button in your broom-closet-sized bedroom.
Not that station life is easy going. Mike Fincke, MS '90, the American who has spent the most time in space, including two stints on the station, says the schedule is full and varied. You never know exactly what the day will hold until connecting with Mission Control after breakfast. Houston might tell the astronauts to work on science experiments, prepare for a space walk or repair toilets.
"Some days you're so busy, you just float by your friends," Fincke says.
Exercise remains a constant. Astronauts must spend two hours a day at the gym, a non-negotiable designed to offset the ravages of weightlessness—notably muscle atrophy and bone-density loss. Stationary biking and running are simple enough with straps and harnesses to connect you to the machines, but "weight lifting" in microgravity requires some ingenuity. Astronauts fight a vacuum system to simulate free weights.
At least their sweat tends to evaporate or stay in place rather than run all over the machines, Fincke says. The evaporated sweat, like urine and other humidity, is recycled back into the water system. The space station is a waste-not, want-not kind of place where human waste in any of its varieties isn't easily discarded. During Saturday housekeeping, Helms says, she was amazed at all the detritus in air filters—mostly skin and hair.
The peak experience for many crew members is the spacewalk—an arduous endeavor that requires five hours just to get suited and out the door. The only thing between you and the rest of creation is your visor, Fincke says, a prospect that can cause even a highly trained astronaut to gulp.
GEARING UP: Mike Fincke works on spacesuits in the Quest airlock of the ISS in 2004. (Photo: NASA)
"When you first open up that hatch and you look out at the Earth and the vacuum of space, you're going, 'Holy smokes! What am I doing? How did I get to this point?' " Mike Hopkins, MS '93, told a crowd at a NASA event after returning last year from 166 days in space, including two space walks lasting a combined 13 hours.
Helms shares the record for the longest single space walk: 8 hours, 56 minutes. Even compared with the astounding views from inside the station, the beauty outside is a revelation—like getting out of your car at the Grand Canyon to really take things in. Though there wasn't a lot of time for dwelling on it, Helms says she spent one memorable 10-minute reprieve soaring over the Middle East and Africa.
The crew signs off after about a 12-hour day, leaving members free for their own pursuits. Helms liked to watch movies. Fincke says he often read email or e-books and talked to his family on the phone. About the only aspect of space he dislikes is missing his wife and kids, one of whom was born when he was in orbit. He was there via telephone.
In his down time, Ed Lu, PhD '89, resolved to focus on things he could do only in space, like taking photos of Earth or perfecting his flying skills. Soaring in zero gravity takes practice; push off wrong and you could find yourself rolling.
Many astronauts—Lu in particular—say being in space made them realize how precious and fragile Earth is.
"You look at the Earth day in and day out, and you look at the craters on the moon day in and day out. And you go, 'Man, at some point, somebody somewhere needs to do something about this,' " Lu says. "You understand our home is at risk at some level."
Lu now heads a nonprofit, Sentinel, that plans to launch a private orbiting telescope to track killer asteroids. The launch date is slated for 2019.
Fincke says he used to hit the hay around 11 p.m. Greenwich Mean Time (the idea of a 24-hour day is an artificial import when you've got 16 sunrises and sunsets). While floating in air sounds like an ideal mattress, a good night's sleep isn't always assured. Some astronauts deal with muscle pain caused by elongation of the spine that can add up to two inches to height in space. Their sleeping bags are designed to be baggy so they can curl up to relieve the aches, Fincke says.
Returning to Earth is its own challenge, as astronauts must readjust to gravity and the speed of daily life here. Lu's transition, though, may have been uniquely testing. Unlike the years of notice most astronauts have before a mission, he was pressed into emergency service after the space shuttle Columbia disaster in 2003, which grounded the shuttle fleet.
He was given two days' notice before flying to Russia to train 16 hours a day, seven days a week for nine weeks to learn how to fly a Soyuz rocket to supply the space station. He remained at the station for six months with just one other crewmember.
Lu returned home to a disastrous yard, a disconnected phone, an out-of-registration car that wouldn't start, a dead air conditioner, moving boxes full of mail and 10,000 unanswered emails. It took him six months to get it all straight.
"The physical aspect of coming back? Trivial," he says. "Getting your life back in order? Really hard."
Sam Scott is a senior writer at Stanford.
