Secrets of surviving in orbit

Three former astronauts have been interviewed by the BBC to understand life in space on the International Space Station (ISS). Every five minutes of an astronaut's day is set aside for mission control on Earth. Maintenance or science experiments take up most of the time on the ISS, which is about the size of Buckingham Palace - or the size of an American football field. The ISS has six laboratories for experiments, and the astronauts wear heart, brain and blood monitors to measure their responses to the physically challenging environment. But how is life there?

In June, two American astronauts left Earth, thinking they would only spend eight days on the International Space Station (ISS). 

But after concerns began that the Boeing Starliner spacecraft is unsafe to return, NASA has pushed back Suni Williams and Butch Wilmore's return date to 2025.
Now they are sharing a space the size of a six-room house with nine other people.

Williams calls it her "happy place," and Wilmore says she's "grateful" to be there.
But what does it really feel like to be 400 kilometers above the Earth? How do they deal with tricky crewmates? How do they exercise and how do they wash their clothes? What do they eat - and more importantly, what is the "smell of space"?

Speaking to BBC News, three former astronauts reveal the secrets of surviving in orbit.
Every five minutes of an astronaut's day is set aside for mission control on Earth.
They wake up early. Around 06:50, they wake up from phone-booth-sized bedrooms in the ISS module called Harmony.

"It has the best sleeping bag in the world," says Nicole Stott, an American astronaut with NASA who spent 104 days in space on two missions in 2009 and 2011.
Separate rooms have laptops, through which the crew can contact family, and a corner where personal belongings such as photographs or books can be placed.

Astronauts can use the bathroom, a small room with a suction system. Normally, sweat and urine is recycled into drinking water, but a problem with the ISS means the crew can only store urine for now.

Then the astronauts can get to work. Maintenance or science experiments take up most of their time on the ISS, which is about the size of Buckingham Palace - or the size of an American football field.

“Inside it looks like there are several buses joined together. For half a day you might not see another person," explains Canadian astronaut Chris Hadfield, commander of the Expedition 35 mission in 2012-13. "People don't move through the station quickly. It is a big and quiet place".

The ISS has six laboratories for experiments, and astronauts wear heart, brain and blood monitors to measure their responses to the physically challenging environment.

"We're like laboratory animals," says Stott, adding that "space puts bones and muscles into an accelerated aging process, and scientists can learn from that."

If the astronauts can, they work faster than mission control predicts.

"Your game is to find five free minutes. I would fly to the window to see anything passing by first. "I was either writing music, taking pictures or writing something for my kids," says Hadfield.

The lucky few are asked to take spacewalks, leaving the ISS to venture out into space. Hadfield has committed two of them. 

"These 15 hours outside, with nothing between me and the universe except the space helmet, has been very stimulating and an otherworldly experience." 

But that spacewalk may reveal something new to the space station — the "metallic smell of space."

"On Earth we have different smells, like the smell of the washing machine or fresh air. But in space there is only one smell and we get used to it very quickly," explains Helen Sharman, the first British astronaut, who spent eight days on the Soviet Mir space station in 1991.

Objects that go outside, such as the suit or scientific equipment, are affected by the strong radiation of space. "The radiation forms free radicals on the surface and they react with the oxygen inside the space station, creating a metallic smell," she says.

When she returned to Earth, she valued sensory experiences more. "There is no weather in space - no rain to fall on your face and no wind to touch your hair. I appreciate these more since then," she says, 33 years later.

Between jobs, long-stay astronauts must do two hours of exercise each day. Three different machines help them overcome the effects of living in zero gravity, which reduces bone density.
Advanced resistance exercise equipment (ARED) is good for squats and lifting light and heavy weights that get all muscle groups working, says Stott.
The team uses two running machines, which they have to strap into so they don't fly, and a pedal machine for endurance training. 

A pair of pants for three months 

All that work creates a lot of sweat, Stott says, which leads to an important problem — laundry.

"We don't have washing machines - just water that forms lumpy masses and some soapy stuff," she explains.
Without gravity pulling sweat away from their bodies, astronauts become covered in a layer of sweat — "much more than on Earth," she says. "I could feel the sweat building up on my scalp - I had to wipe my head. You didn't dare shake it because it would fly everywhere."
These clothes become so dirty that they are thrown into a burning cargo vehicle in space.
But according to her, their everyday clothes stay clean. 
"In zero gravity, clothes fly on the body, so fat and other things don't touch them. I had a pair of pants for three months," she explains.
Instead, food was the biggest risk. 
"One would open a can of, for example, meat and gravy," she says. "We were all alarmed because little balls of gravy would start flying. "People were flying backwards, like in the movie Matrix, to get away from the gravy."
At some point another spacecraft may arrive, to bring a new crew or supplies of food, clothing and equipment. NASA sends several supply vehicles a year. Getting to the space station from Earth is "amazing," Hadfield says.
"It's a life-changing moment when you see the ISS in the eternity of the universe - seeing this tiny bubble of life, a microcosm of human creativity in the dark," he says.
After a long day of work, it's time for dinner. Food is mainly placed in packages, divided into different places according to the nation.
"It was like camping food or military rations. "Okay, but it could be healthier," says Stott. "My favorite has been the Japanese horseradish, or Russian soups or cereals."
Families send additional food packages to their family members. 
"My husband and son would pick out little sweets for me, like chocolate-covered gingerbread," she says.
The team shares food most of the time.
Astronauts are pre-selected by personal attributes - tolerant and calm - and trained to work as a team. This reduces the likelihood of conflict, Sharman explains.
"It's not about tolerating someone's bad behavior, it's about making it known. And we always support each other," she says.

The psychological impact of seeing the Earth from orbit

And finally, time to sleep, and time to rest after a day of noisy environments, where the fans work constantly to disperse the carbon dioxide for the astronauts to breathe, making it noisy, like a very office. noisy.
"We can sleep for eight hours - but most stay at the window looking at the Earth," says Stott.
All three astronauts have spoken about the psychological impact of seeing planet Earth from 400 kilometers in orbit.
"I felt so insignificant in that vastness of space," says Sharman. "Seeing the Earth so clearly, the swirls of clouds and oceans, made me think about the geopolitical boundaries we construct and how we really are completely interconnected."
Stott says he enjoyed living with six people from different countries and "doing this work on behalf of all life on Earth, working together, figuring out how to deal with problems." 
"Why can't this happen on our planet?" she asks.
In the end, all the astronauts have to leave the ISS – but these three say they'd return without a second thought.
They don't understand why people think NASA astronauts Suni Williams and Butch Wilmore are "trapped."
"We dreamed and worked and trained our whole lives hoping for a long stay in space," says Hadfield. "The greatest gift you can give a professional astronaut is to let them stay there longer."
And Stott says that as she left the ISS she thought, “You have to pull my hands out of here with all your claws. I don't know if I will be able to return."