Out There

When astronaut candidates begin training, one of the first things they have to master, oddly enough, is swimming. In addition to becoming scuba-certified, they have to swim three lengths of a 25-meter pool without stopping. Then they have to do it again in a flight suit and tennis shoes. This prepares them for spacewalks, also known as Extra-Vehicular Activities (EVAs), which refer to any work that’s done outside a spacecraft. Astronaut candidates also undergo extensive training in hypobaric and hyperbaric environments, and with periods of simulated weightlessness.

Missions to the ISS can require an additional two or three years of training after the initial astronaut candidate period. At the Sonny Carter Training Facility, also known as the Neutral Buoyancy Laboratory, a 6.2-million gallon water tank is used to simulate weightlessness, and a model of the International Space Station, fully submerged, allows them to practice everything they’ll be doing at the ISS, from such daily activities as preparing food to spacewalks.

Since the end of the US Space Shuttle program in 2011, the Soviet Union’s Soyuz capsule has provided the only transportation for astronauts and cosmonauts going to the International Space Station. Before takeoff, the team comes together at the Yuri Gagarin Cosmonaut Training Center in Star City, Russia, where they undergo a few more weeks of training. When it’s time to leave, the Soyuz, with 3 people fitting snugly aboard on top of a Soyuz rocket, launches from Baikonu, Kazahkstan, and travels the approximately six hours it takes to get to the ISS.

– Astronaut Scott Kelly

While it takes around 9.5 minutes to get to space, it used to take a total of two days to arrive at the ISS because of the extended docking process. But in March 2013, the Soyuz was able to complete the first leg of the journey in under six hours, bringing down the number of orbits required for alignment from 34 to about four. The forty-plus saved hours make a big difference when you’re crammed into a capsule in a massive spacesuit.

Up until March of this year, typical missions to the ISS have lasted between three and six months. But now, American astronaut Scott Kelly and Russian cosmonaut Mikhail Kornienko are almost halfway through the first ever one-year mission to the ISS. More explicitly than any previous mission, the goal of the one-year experience is to see how the two men's bodies and minds react to such an extended period in space. This will help NASA determine how far humans are from being able to handle–physically and psychologically–a trip to Mars, which could take several years. To get a sense of what that would be like, here’s a look at Kelly and Kornienko’s home:

Most people think it’s zero gravity that causes astronauts to float, but on the ISS that’s actually not the case. In fact, the station is subject to 90 percent of the gravity that’s found on the earth. Astronauts float on the ISS and outside on spacewalks because they are in a state of free-fall. They miss the earth because the speed at which they are traveling–17,500 mph–is enough to counteract the force of gravity that would otherwise pull them down, so they just keep falling, as if they’re always on the downhill side of a roller coaster. Even though they understand all this, they say, the feeling of weightlessness never gets old.

– Astronaut Mike Fincke (The Atlantic)

However exhilarating, the state of weightlessness can actually be damaging to astronauts’ health. Over extended periods of time, astronauts can experience muscle weakening and bone loss (at a rate ten times that of an earthbound 70-year-old), because their bodies aren’t forced to work against the pull of gravity. To counteract this, astronauts have to exercise for approximately 2 hours a day in machines that look quite different from those on earth.

– Astronaut Mike Hopkins (5,200 Days in Space, The Atlantic)

In many elements of the ISS astronaut experience, there are attempts to approximate the creature comforts of life on earth. But, obviously, it’s never quite the same, and sleep might be the quintessential example of that. When it’s time to turn in for the night, astronauts don comfy pajamas, open the doors to their sleep pods, and zip themselves into a sleeping-bag-like enclosure. In space, though, they never actually lie down, knowing that when the lights go out and the doors close, they’ll just float in their sleeping bags, unaware of which way is up.

A lot of people think astronauts’ food is nothing like what we eat on earth–that it’s all unrecognizable and, well, gross. But while almost everything they eat is either freeze-dried, thermostabilized (i.e. canned but not stored in metal), or powdered, requiring rehydration—and while some foods are off the table entirely because they don’t conform to NASA’s requirements—meals aren’t as limited or unappetizing as we think, and the menu isn’t completely out of astronauts’ hands. There are more than 200 items on the “core menu” that NASA offers, about 110 of which have been developed from scratch by the food lab scientists. Before traveling to the ISS, astronauts meet with NASA’s food lab to try out their options and make some selections for what they want to eat (each gets to pick nine for every six-month stint on the ISS). One of the astronauts’ favorites is freeze-dried shrimp cocktail with a spicy cocktail sauce, both of which have to be rehydrated.

Every once in a while, though, the astronauts get a shipment of fresh fruits, and even non-freeze-dried ice cream. And when that happens, it’s a party!

– Astronaut Edgar Mitchell (Overview)

The ISS is, above all, a laboratory. There are usually more than 200 experiments happening at any one time, which include everything from observing ant colonies to attempting 3D printing (in a weightless environment) to testing humanoid robots. Most of the experiments are focused on understanding how conditions in space affect, well, everything—including the astronauts themselves. NASA astronaut Cady Coleman once referred to herself as a "walking, talking osteoporosis experiment" to see how human bodies hold up during extended periods of weightlessness, with the hope of better understanding how we can make space travel safe enough to go farther.

Since the first expeditions to the ISS, there have been 188 spacewalks. Depending on the purpose, each one tends to last between five and eight hours. Spacewalk missions include testing equipment, making repairs to the station, and conducting experiments in open space. Not only can it be terrifying, it can also be extremely physically demanding, in part because the suits are pressurized and inflated with oxygen.

– Astronaut Mike Foreman (The Telegraph)

For every hour they will spend on a spacewalk, astronauts train for seven in the giant pool in the Neutral Buoyancy Laboratory, where they perform virtual-reality simulations wearing gloves that allow their movements to appear integrated into a video of what they’ll be doing on the spacewalk.

No matter how incredible it is to float freely in space, to gaze at the earth during the sixteen sunrises or sunsets the crew experiences every day, there is, of course, an incredible longing for home and a need to stay connected. Luckily, they can call their families whenever they want from an IP phone and receive presents from loved ones during the holidays. And when it’s just them up there on the Fourth of July, straining to remember what BBQ smells like, sometimes they can catch a glimpse of fireworks on earth.

– Cosmonaut Mikhail Kornienko (Time)

– Astronaut Dave Wheelock (ABC News)

The trip back to earth from the ISS is quite different from the six-hour, rocket-propelled first leg. This time astronauts get back into the Soyuz and, after separation, do a careful de-orbit burn to slow down and achieve exactly the trajectory that will allow the capsule to reenter the atmosphere safely. After that, the long fall back to earth takes less than 3.5 hours.

Reentering the earth’s atmosphere means reintroducing the body to the sense of its own weight. As the astronauts start to experience that feeling in the capsule, they’re pulled deeper into their seats, which helps them brace for landing. Parachutes deploy and rockets fire from below to slow down the descent, which culminates in a relatively soft landing and rendezvous with a search and rescue team.

– Astronaut Daniel M. Tani

And they are never the same, perhaps most of all because they have a new perspective on home, having seen Planet Earth from afar. As ISS astronaut Nicole Stott puts it: “I don't know how you can come back and not, in some way, be changed. It may be subtle. You see a difference in different people in their general response when they come back from space. But I think, collectively, everybody has that emblazoned on their memories, the way the planet looks. You can't take that lightly."