I wonder why no women were involved in the experiment. Will we not be sending women on the first mission to mars? Also, I would imagine that regular sexual activity would make for a more placid social environment.

I'd guess the answer to the isolation problem is increased reliance on virtual worlds and online interaction. Though the lag might be dreadful when communicating with the Earthlings.

500 days? Thats almost 2 years of your life given over to essentially a useless experiment. What are they going to learn? People don't like cramped conditions, but they can deal with it. Give them movies and books to read and don't be a d*ck when you have to share some cramped space with people.

Are they going to cancel the mission to mars if it turns out people would become extra-irritable?

Hats off to the volunteers. That's a lot to do and not even get to go to Mars.

I don't see a reason for these useless and throwing life away experiences if the purpose is just making the astronauts used to isolation. I kind of get it if it's to study something psychological, but we have so many prisoners in almost the same conditions...

After the moon, everything is just too far away to travel. We can study Mars very well with the robot approach. We're just throwing astronauts life away for our stupid need of putting Men in Mars, which I dare say is utterly pointless.