Image copyright Miguel Angel

Could you leave everyone you love for the chance to settle on Mars? Sonia Van Meter describes herself as an "aspiring Martian" - she hopes to be one of the first humans on the planet in 10 years' time. But it would mean never seeing her husband again.

"I don't think you can apply for something like this and not be the tiniest bit insane," says Sonia Van Meter. "But this is the next great adventure, and I'm going to do absolutely anything I can to be a part of this."

The 35-year-old political consultant from Austin, Texas, is one of 705 people in the running to form a 20- to 40-strong human colony on Mars - a group whittled down from 200,000 who sent applications to Dutch not-for-profit organisation Mars One last year.

"I thought: 'Shoot, this sounds like fun!'" she says. "I didn't think there was the slightest chance that I would be selected, I just wanted to be a part of it."

I am incredibly fortunate in that I have a remarkable family to leave behind Sonia Van Meter

For her husband Jason Stanford, her application - and the fact that she now appears to have a 35-to-one chance of leaving forever - evoked mixed emotions.

"Like any good red-blooded American male, at first I thought this was all about me. I thought: you're leaving me," he says.

Over time he changed his mind. "The more she talked about it, the more I realised she was doing this for the right reasons - she was doing this to show humanity what we can all do if we work together," he says.

Living without her "will be an agony that I will have to share with the world" he wrote in an article for a Texan magazine.

Media playback is unsupported on your device Media caption Sonia's audition video: "My purpose on this mission is to help people back on Earth to look up"

"I'll be Mr Sonia Van Meter for the rest of my life, showing up to cut the ribbon at Sonia Van Meter High School and telling her story here on Earth."

Van Meter herself pays tribute to her loved ones, saying: "I am incredibly fortunate in that I have a remarkable family to leave behind."

Mars One's plan is to ship four Marstronauts out to the red planet every two years, beginning in 2024, until there is a settlement of up to 40 - the finance coming from a reality TV show made by the people behind Big Brother.

Van Meter's love for space dates back to her childhood, when the only weekday programme she was allowed to watch was Star Trek - a show which she feels was about far more than space exploration.

Image copyright Van Meter

"It was about being the best version of yourself and working together in tremendous collaboration," she says. "Those are themes that I think really stuck with me."

Even now, as an adult, she watches the film Apollo 13 - about the 1970 space mission that nearly ended in disaster - several times a year.

"Look at all the hundreds of people who came together and made sure that those three human beings came home alive safely," she says.

"If we were capable of that kind of triumph way back then, imagine what we're capable of now.

"I don't know how anyone can know about what we've done in space and not be moved, excited and thrilled about the future."

Image copyright Getty Images

The race to Mars

Mars One is just one of several initiatives to send humans to Mars.

Inspiration Mars, backed by the first-ever space tourist Dennis Tito, plans to send a married couple to fly past Mars in 2018. The journey would take 18 months.

Space X, a private company under contract with Nasa, wants to build a large, self-sustaining city on Mars by 2026.

Nasa itself doesn't plan to get humans to Mars before 2035.

In November she and Stanford will celebrate five years together, but they will know that they may only have another 10 to go. Will it feel odd? Not according to Van Meter.

"He once told me he'd love me to the ends of the Earth and beyond, no matter what. We didn't anticipate that the 'what' would be going to another planet."

Stanford, meanwhile, refers back to their marriage vows.

"Contemplating a life without your life partner is a daunting thing, but then I went back and re-read the marriage vows looking for an out-clause - and there was no asterisk," he says.

"I promised to support her in whatever adventures we chose - we actually explicitly said that our lives would be an 'adventure' - and this is what she has chosen as her life's goal."

He adds: "I'm not saying I shouldn't have done a better job writing the vows."

A sense of humour has been important recently, as the couple have come in for quite a lot of criticism. "Nothing says 'I love you' more than a one-way trip to Mars," read one tweet.

At first, Van Meter was upset by the negative comments.

"I really thought they'd look at me and see what an awesome opportunity this is, like watching the moon landings," she says.

"What I was not prepared for was hearing that I'm a horrible wife, that I'm a horrible stepmother, that I'm selfish and arrogant."

Media playback is unsupported on your device Media caption Construction phases of the planned Mars One settlement

Her stepchildren, Henry, 13, and Hatcher, 11, think it's "cool that their stepmum has decided to be this hero," Stanford says.

There is one thing about their life post-separation - if Van Meter is selected for Mars - that the couple prefer not to talk about publicly.

"There are many aspects to discuss," says Stanford. "My sex life isn't one of them."

Stanford compares the magnitude of the Mars mission to those of Columbus or Magellan (the first to circumnavigate the earth).

"They didn't stay home because they were married," he says. "They explored, and they were assumed probably to be facing great peril. The peril here is guaranteed, and the fact she's willing to take this on for noble reasons is something I can get behind."

The mission, if it goes ahead, will be dangerous, some say suicidal.

"This is the biggest risk I'll ever take, but some things are worth that risk," says Van Meter. "If there isn't something out there you're willing to put down your life for, you haven't really found what you want in life. I feel quite lucky."

Before the rocket takes off, candidates face nine or 10 years of preparation on Earth - a full-time job, according to Mars One, which will be chronicled as a reality TV show. Whatever form the programme takes, it won't be Star Trek. There are plans to select the first "human ambassadors" to Mars by public vote.

Image copyright Bryan Versteeg/MARS ONE Image caption Mars One settlers will have to be good with greenhouses

What will life be like in that small group of pioneers far out in space? Boring, thinks Stanford. Claustrophobic and uncomfortable, guesses Van Meter, but with plenty to do. "There will be so much activity required of us just to keep us alive that I don't know there will be a lot of time to focus on the lack of fresh air and sunshine," she says. Among other things, they will have to grow their own food.

Will it ever actually happen? Van Meter is optimistic. "Before magnificent and tremendous things can happen, somebody first has to say, in the face of outrageous odds, in the face of all of the naysayers, that we are going to do this," she says. "Mars One has thrown down their gauntlet and now it is up to them to meet the challenge."

When Van Meter's father, Ike, heard that she was one of those selected from the 200,000, he asked her how she could choose to do such a thing.

"Imagine the grave site of the first person to die on another planet," she replied. There was a pause. Ike said: "Gosh, I see your point."

Sonia and Jason spoke to Outlook on the BBC World Service. Listen again on iPlayer or get the Outlook podcast.

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