Allow me to express my skepticism on this whole idea of sending people to Mars, one way, to colonize the place and establish a toehold in space for human exploration.
No matter what people say here, while they're on Earth, there is no way that public opinion will tolerate the idea of leaving them there and doing nothing if someone on Mars decides that they want to return home. I suspect the people involved are not that naive and know that there will be, after a reasonable interval, two way flights to Mars that they can take advantage of and return home.
There are far too many ways out of this--they will I was lied to, I changed my mind, I miss my family, my situation has changed, and I didn't know how good I had it until I left everything behind. Not everyone, of course, because all it takes is one. But still.
I doubt very much if this will ever happen. And, if it does, we can begin the countdown to a meltdown before someone has to be brought back on a special, expensive rescue mission.