The Mars One mission is a unique endeavour because while science and discovery will play a key role, its story is rooted in something far simpler and unpredictable: human nature.
It is a mission founded on the principle that human beings are capable of doing extraordinary things just so they can say 'I've done this, we have now done this'.
In Episode 2 of this five-part series, Citizen Mars looks at the lives and personalities of the humans that could ultimately be taking the one-way trip to start a colony on Mars.
These candidates have a made a decision which is that if and when the mission is ready, they will leave everything they've ever known behind and will start a new life on another planet.
It sounds romantic but it won't be. They will be devoting the rest of their lives to staying alive. Maintaining the equipment that keeps them breathing, eating and sleeping.
That doesn't leave much room for anything else, including all the emotional feelings and urges that can rule and drive us as humans from love to sex to rage. There won't be time for any of that.
So what kind of person would agree to this? We find out...