what hoax?

Are the viewers the ones who are being hoaxed? Surely that would be the biggest hoax?

I would have thought that the programme maker could be sued if somebody took offence and/or gave up everything to go into space. it doesn't make sense. What's more it's cruel. That's what makes me think the cadets are in on it, the actor may or may not be in on it, and its the viewers who are being hoaxed.

Inferred consent has been given. All participants will have signed a contract agreeing to participate. The fact they have not been told all is therefore irrelevant.

And I reckon you're a hoax.

I just find it so cruel as an idea for entertainment, I'd like to believe it isn't true, and it's just a joke on the viewers.

Can you consent to a hoax?

Yes - very easily if the contract is worded correctly.