QUESTION:
What would happen if the astronauts got sick and tired of each other and did
not do what are support to be doing?

ANSWER from Nilay Bekiroglu on April 20, 1998:

I'd say that this is probably unlikely to happen as the astronauts go through 
extensive training with each other before they go into space. And they must all
 realize that to live in space and return home safely, they must all work 
together. More detailed information about the astronauts and space shuttles 
may be found at a sister project called Space Team Online. The url is 
http://quest.arc.nasa.gov/space/