I don't think most people realize how hard t his would be.

You can't be a smoker since obviously you can't smoke or have a nicotine addiction, no pot, you can't drink alcohol, no caffeine addictions so no coffee, energy drinks, pop/soda.

If you can't stay off the Internet for any amount of time, or stay off your mobile phone - no texting.

Medical history is a problem too. Any medical conditions like diabetes, high blood pressure or anything that require medication. If you can't live in the middle of nowhere without some sort of support, you can't go.

Even sex, is everyone going to be celibate? If two people started seeing each other romantically it would be very uncomfortable for the others in the "space station". Or maybe everyone is given masturbation time!

What about religion. You can't let religion interfere with your duties since every action is meant to keep you alive. What if a heated discussion starts about Creationism versus Science when you're halfway to Mars?

People have a lot of habits and needs they don't realize you practically have to be a recluse to be cooped up for so long. I think anyone from an urban area is the worst candidate, anyone from a rural area would be the best. Even better would be someone from an under developed or Third World country who is well educated in sciences.

The perfect candidates would be a well educated, non-religious, young, from a rural area, no family history of serious diseases and also have a clean medical history; no appendix, tonsils, spleen and no diseases.