1) About how long is a typical tour of duty on something like that? Would it be reasonable for someone to be out in the field for years, or do they restrict how long you can sign up for?
2) I know that when people who have done things like this come back they often go through culture shock. Is there anything the organizations due to help them acclimate again? How long does the culture shock last? What are typical symptoms? (eg things like being disgusted at how decadent their former life was in comparison to those who live in third world/war-torn conditions)
3) If someone really enjoyed the work and wanted to keep doing it, what are reasons that would force him to have to quit and go home? I'm looking for reasons within doing the job itself, not external reasons like a death in the family.
4) What kind of communication, if any, is typical with their friends and family back home? Is it just letters are email and phone calls also common?
5) Are they made to take vacations to go home, or would it be possible for someone to be out there to go as long as they wanted without a break?