Follows 12 ordinary people as they embark on a physically and mentally demanding training regime to prove they have got what it takes to survive the extreme and unforgiving environment in space as an astronaut.

The remaining candidates face a simulated emergency splashdown where they have to escape from an underwater capsule.

The remaining candidates face more tests, including assembling a large cube underwater, learning basic Russian and attempting to dock the Soyuz Space Capsule with the International Space Station.

The candidates head off to a secret facility in Sweden where they are deliberately deprived of oxygen to see if they can recognise the signs of hypoxia.

Follows 12 ordinary people as they embark on a physically and mentally demanding training regime to prove they have got what it takes to survive the extreme and unforgiving environment in space as an astronaut.

The finalists dive down to the Aquarius underwater research laboratory in the Florida Keys, a training facility used by NASA. Then, they return to London's Science Museum to find out who has what it takes to be an astronaut.