Astronaut Chris Hadfield critiques Bullock's new flick 'Gravity'

Everyone’s favourite Space Canadian, astronaut Chris Hadfield, says box office smash Gravity is a visual delight — and pretty damn close to being in space.

But it got one big thing wrong: The underwear.

In an interview with American chat show host Conan O’Brien, Hadfield, 54, said his five-month trip on the International Space Station taught him that if there’s one thing you don’t look like when you take off your space suit, it’s an “underwear model”.

In fact he said you’re basically wearing a “Halloween costume” of heaters and coolers, have a “big pull-up diaper” on underneath, and your “hair looks like rat fur”.

Sandra Bullock starring in box office smash ‘Gravity’ which is showing in Irish cinemas at the moment

Hadfield praised the Hollywood blockbuster as being “visually just like being on a spacewalk”.

Canadian astronaut Chris Hadfield on board the International Space Station

However, on the matter of Sandra Bullock’s underwear, he said a more realistic depiction would have placed her in adult nappies. “Inside our space suit, we’re wearing… a Halloween costume, which is a liquid cooling garment,” he said.

Hadfield has said the movie is a visual delight, but insisted a more realistic depiction would have placed Bullock in adult nappies.

He added that the space walk scenes in Gravity were “better than any space movie ever made”.

The astronaut, who was nine when Neil Armstrong became the first man to walk on the moon in 1969, is best known for his rendition of David Bowie’s ‘Space Oddity’ while on the International Space Station, which received millions of views on YouTube, and his popular Twitter, Tumblr, and Reddit social media activity.

Earlier this year, the outspoken Canadian posted the first episode of his new show, Chris Hadfield’s Space Kitchen. The first recipe was a tortilla filled with honey and peanut butter.