Josh Richards is in the running to be one of the first humans to set foot on Mars. The catch is, he won't ever be able to come back to Earth.

The red-headed 29-year-old Aussie comedian is one of the remaining 700 candidates for the Mars One project, reduced from an initial 200,000 applicants.

Next July those numbers will be cut to 24 in what's being billed as the biggest media event in history, with the billions to be made from the broadcasting rights helping fund the wildly ambitious project.

Then in September 2024, two men and two women will set off on the seven-month journey to Mars.

And that's where they'll stay, for the rest of their lives.

Far from being daunted by the prospect of leaving behind everything and everyone he loves, Josh is excitedly anticipating the possibility of being one of the chosen few.

In Newcastle this weekend for the National Young Writers Festival, Josh explains that he's wanted to be an astronaut since he was seven, and saw Andy Thomas selected as Australia's first professional astronaut.

But his parents told him he would need to be an American citizen for that to be a real possibility, so he initially pursued a career in the army as a combat engineer, and even spent time with a commando unit in the UK.

Josh also studied applied physics and psychology at university, worked in mining engineering as a blaster and was a science advisor to renowned contemporary artist Damien Hirst, before winding up in comedy.

He was so disappointed that humans, who last walked on the Moon in 1972, seemed to have abandoned their dreams of exploring space that he was building a comedy routine around it when he heard of the Mars One project.

Suddenly his childhood dreams of going to space came flooding back and he threw himself into the application process with a passion.

'Mum was genuinely horrified'

But there were some bumps in the road, like his mum finding out via his online blog that she could potentially be losing her son forever.

"Mum was genuinely horrified when she first found out," Josh says, explaining there was a teary phone call from his mother back home in Australia to him in the UK.

But she's now his biggest supporter, helping organise his many school visits where he talks to kids about space exploration.

Knowing that he might be leaving the planet for good in around 10 years has meant some big adjustments in Josh's life.

"I'd never buy a house," he says, adding that when people give him gifts he quickly passes them on.

And relationships are a very tricky area.

"It makes it pretty challenging," Josh says, with the prospect of going to Mars and never coming back not the greatest pick-up line, even with the glamour of being an astronaut.

While some of Josh's friends wish they could talk him out of his plans, they're all supportive because they know how much it means to him.

"A lot of people get really rubbed the wrong way with the whole one-way element," Josh says.

"For me, it's actually vital that we do go one-way."

Currently there's no technology that could bring the Mars One explorers back, but Josh says the project will spur such research on.

"And maybe they'll find a way to bring us back, but we need to go with the intention not to return," he says.

"In many ways I'm treating it like a death in the family."

He recently passed his medical, so it's all getting pretty serious now.

"The reality is that what we're doing with Mars One is so much bigger than the individual," Josh says.

"It's doing something for humans as a species."

Josh is giving several talks at the National Young Writers Festival, and you can find details at their website.

You can find information about the Mars One mission here.

Josh Richards spoke to Jill Emberson from 1233 ABC Newcastle Mornings, and you can hear the entire interview in the attached audio.