Look at the number of mutinies on board sailing ships which took off for 2 and 3 years. Of course the working conditions weren't great on some of them, but even they landed from time to time, saw other people, got fresh food, that sort of thing. They weren't in a capsule with just a few other folks with no hope of any relief for a couple of years.

The sad thing is that so far it doesn't seem possible to predict a proper mix. Do we want loners, people who are comfortable for long periods with limited interaction, do we want extroverts, vying for supremacy and attention, do we want romantic liasons (NO), do we want a therapeutic community/

Actually, communist armies have a pretty good technique where they each belong to a "cell" of about three people, where they can safely criticize and praise each other which minimizes the possibilities of tensions building up. Camaraderie is wonderful, sometimes hard to maintain in the absence of a common, immediate, personal deadly enemy. I don't know if a vacuum would suffice.

Arf