In June, two American astronauts left Earth with the intention of spending eight days aboard the International Space Station (ISS).
But after concerns that their Boeing Starliner spacecraft was unsafe to carry, NASA has delayed the return of Suni Williams and Butch Wilmore until 2025.
They now share a space the size of a six-bedroom house with nine other people.
Ms. Williams calls it her “happy place” and Mr. Wilmore says he is “grateful” to be there.
But what does it really feel like to be 400 km above the Earth? How do you deal with difficult teammates? How do you exercise and wash your clothes? What do you eat and, most importantly, what does “space smell like”?
Speaking to BBC News, three former astronauts reveal the secrets of surviving in orbit.
Every five minutes of the astronauts’ day is divided by mission control on Earth.
They rise early. Around 06:30 GMT, the astronauts emerge from the telephone booth-sized sleeping cabin of the ISS module called Harmony.
“He has the best sleeping bag in the world,” says Nicole Stott, a NASA astronaut who spent 104 days in space during two missions in 2009 and 2011.
The compartments have laptops so crew can stay in touch with family and a corner for personal items such as photographs or books.
The astronauts will then be able to use the toilet, a small compartment equipped with a suction system. Normally, sweat and urine are recycled into drinking water, but a breakdown of the ISS currently forces the crew to store the urine.
The astronauts then get to work. Maintenance and scientific experiments take up most of the time aboard the ISS, which is about the size of Buckingham Palace or an American football field.
“Inside, it’s like having several buses all bolted together. In half a day, you might not see anyone,” says Canadian astronaut Chris Hadfield, commander of the 2012-2013 Expedition 35 mission.
“People don’t rush into the station. It’s big and it’s peaceful,” he says.
The ISS has six laboratories dedicated to experiments, and astronauts wear heart, brain or blood monitors to measure their responses to the harsh physical environment.
“We’re guinea pigs,” Stott says, adding that “space subjects your bones and muscles to an accelerated aging process, and scientists can learn from that.”
If the astronauts can, they work faster than mission control expects.
Mr Hadfield explains: “Your game is to find five spare minutes. I would float to the window and watch something go by. Or I would write music, take pictures or write something for my children.”
A lucky few are invited to take a spacewalk, leaving the ISS and heading into the vacuum of outer space. Mr Hadfield has done two. “Those 15 hours outside, with nothing between me and the universe except my plastic visor, were as exhilarating and otherworldly as the other 15 hours of my life.”
But this spacewalk may introduce something new to the space station: “the metallic smell of space.”
“On Earth we smell lots of different smells, like laundry in the washing machine or fresh air. But in space there is only one smell, and you quickly get used to it,” says Helen Sharman, the first British female astronaut, who spent eight days aboard the Soviet space station Mir in 1991.
Objects that come out of space, such as a spacesuit or a science kit, are affected by the strong radiation in space. “The radiation forms free radicals on the surface, which react with the oxygen inside the space station, creating a metallic smell,” she explains.
When she returned to Earth, she appreciated the sensory experiences much more. “There’s no weather in space, no rain on your face or wind in your hair. I appreciate those experiences even more today,” she says, 23 years later.
Between work sessions, astronauts on long-duration missions must exercise for two hours a day. Three different machines help counteract the effects of life in weightlessness, which reduces bone density.
The Advanced Resistive Exercise Machine (ARED) is ideal for squats, deadlifts and rows that work all muscle groups, Stott says.
The crew uses two treadmills that they must strap themselves onto to avoid floating, as well as an ergometer bike for endurance training.
“A pair of pants for three months”
All that work generates a lot of sweat, Stott says, which leads to a very big problem: washing.
“We don’t have any detergent, just water that forms clumps and soapy stuff,” she explains.
Without gravity pulling sweat away from the body, astronauts end up covered in a layer of sweat – “much more than on Earth,” she says.
“I could feel the sweat rising on my scalp, I had to rub my head. I didn’t want to shake it, because it was flying everywhere.”
These clothes become so dirty that they are thrown into a transport vehicle which burns up in the atmosphere.
But their everyday clothes stay clean, she said.
“In zero gravity, the clothes float on the body, so oils and everything else don’t affect them. I wore the same pants for three months,” she explains.
On the other hand, food posed the greatest danger. “Someone would open a can of something, like meat and sauce,” she said.
“Everyone was on alert because little balls of fat were coming out of the cabin. People were floating backwards, like in the movie Matrix, to avoid the balls of meat juice.”
At some point, another ship might arrive, bringing a new crew or supplies of food, clothing and equipment. NASA sends a few resupply vehicles a year. Getting to the space station from Earth is “amazing,” Hadfield said.
“It’s a life-changing moment when you glimpse the ISS into the eternity of the universe – seeing this little bubble of life, a microcosm of human creativity in the darkness,” he says.
After a hard day’s work, it’s time for dinner. The food is usually put together in packages, separated into different compartments by nation.
“It was like camping food or army rations. It was good, but it could be healthier,” Stott said.
“My favorites were Japanese curries or Russian cereals and soups,” she says.
Families are sending food packages to their loved ones as a bonus. “My husband and son chose little treats, like chocolate-covered ginger,” she says.
The crew mostly shares their food.
Astronauts are screened for their personal qualities – tolerance, relaxedness, calmness – and trained to work as a team. This reduces the risk of conflict, Sharman says.
“It’s not just about putting up with someone’s bad behavior, it’s about calling it out. And we always give each other metaphorical pats on the back to support each other,” she says.
Location, location, location
And finally, off to bed, and time to rest after a day in a noisy environment (the fans are constantly running to disperse pockets of carbon dioxide so the astronauts can breathe, making the noise about as loud as a very noisy office).
“We can sleep eight hours a day, but most people are stuck at the window looking at the Earth,” Stott says.
The three astronauts spoke of the psychological impact of seeing their home planet from 400 km in orbit.
“I felt very insignificant in this vastness of space,” Sharman says. “Seeing the Earth so clearly, the swirling clouds and the oceans made me think about the geopolitical boundaries we construct and how we are actually completely interconnected.”
Ms Stott says she loved living with six people from different countries “doing this work on behalf of all life on Earth, working together, figuring out how to deal with problems”.
“Why couldn’t this happen on our planetary spaceship?” she asks.
Eventually, all astronauts will have to leave the ISS, but these three say they would be back in a heartbeat.
They don’t understand why people think NASA astronauts Suni Williams and Butch Wilmore are “stuck.”
“We have dreamed, worked and trained our entire lives in hopes of spending an extended period in space,” Hadfield said. “The greatest gift you can give a professional astronaut is to allow them to stay longer.”
And Ms Stott says that as she left the ISS, she thought, “You’re going to have to get my clawed hands out of the hatch. I don’t know if I’m going to be able to come back.”
Graphics by Katherine Gaynor and Camilla Costa
