The series was a hoax at the expense of its contestants, who were told they were being trained as cosmonauts at a Russian military base before undergoing a five-day trip into low Earth orbit. In reality, the entire series was filmed in Dore, and the contestants did not leave Earth.
Imagine you take 200 people who answered an ad seeking “thrill seekers” and to be on TV. Then you psychologically weed it down with questions in order to pick the 6 most gullible, groupthink, extroverts.
That’s how they got the people. Out of all the applicants. However many their were, they took the most gullible extroverted ones they could get.
It never would have been pulled off as a success with regular people.