Astronaut reveals what it takes to do the hardest job in the universe

Chris Hadfield had a 32-year-career doing something many people dream of but only a select few ever get to do. The 58-year-old Canadian was accepted into the Canadian astronaut programme in 1992, first flew in space in 1995 and has walked in space as well as served as commander of the International Space Station.

But it's probably for the video of his performance of David Bowie's Space Oddity that Hadfield is recognisable to most people - the YouTube video has been watched more than 37million times since Hadfield posted it during his final mission in 2013.

Speaking from Canada, Hadfield says: "I took so many pictures of the world but South Africa - your lens is naturally attracted to it because you've taken all that time to cross the Atlantic and then you see the bulk of Africa rising up and then the rugged nature of the rock -it's a naturally photogenic and beautiful part of the world."

WATCH Chris Hadfield perform David Bowie's Space Oddity in space

Hadfield, who has spent the years since his retirement travelling the world talking to schoolchildren, businesses and governments about his experiences as an astronaut, is still amazed at how much curiosity and excitement the idea provokes, just as it did when he was a young man growing up in rural Ontario and dreaming of the skies above.

Described as the most social media-savvy astronaut in history, Hadfield has now developed a television show with the BBC in which 12 ordinary people are put through the rigours of the process space agencies use to select potential astronaut candidates.

He says the show, The Hardest Job in the Universe, is intended "to make it as identical to the real process as we possibly could so that people could actually see what's involved because most people have misunderstood the skills and capabilities involved".

The overall winner won't get to fly in space, but as Hadfield points out, that's part of the reality of the job as well. When he applied to the Canadian Space Agency, "5,330 applied and they chose four of us and, of those four, one didn't fly in space so there's no guarantee in the astronaut business".

You might think Hadfield's Space Oddity rendition is an indicator that the hardest part of an astronaut's life might be a sense of loneliness. But Hadfield doesn't see it like that, preferring to view his performance as "a celebration of the fact that our culture is moving away from Earth. We aren't just robots up in space, we are the early settlers, a little subset of human culture developing independently from the planet and there's a lot of fun going on, on a spaceship and it's joyous."

As for the most difficult part of the hardest job in the universe, Hadfield asks me to imagine: "If you had trained for 10 years and spent thousands of hours in simulators, learnt to speak Russian and fly a spaceship in Russian and you had to remember everything, and it was life or death if you forgot? It's the memory task that's the hardest part."

With all the talk of humanity's next challenge, the frontier of Mars, Hadfield believes that "the idea of exploring Mars is both inspirational and inevitable but there's a lot of false hope in how quickly that's going to happen because most people don't understand the complexity of it".

He's thinks it's more likely that "we'll have a base on the moon for a generation or two before we've learned enough to go safely to Mars. We need people like Elon Musk but we also need people like the candidates that we put through this selection who have that level of motivation, optimism, personal commitment and brilliance."

• 'Astronauts - the Hardest Job in the Universe' begins on Sunday October 8 at 4pm on BBC Earth DStv Channel 184.

• This article was originally published in The Times.