so i live off campus in an apartment....what do people do when they leave for co-ops? break their lease....wait til its done....get someone to move in to pay for stuff?

For summer co-ops, what I have seen is that people will get a friend of theirs whom they trust (and who most likely lives in the dorms or is greek) to takeover their place just for the summer--this way neither party is breaking the lease. You don't have to move your shit out, just take what you absolutely need for the job (this takes care of the moving pain in the ass) and your friend has a fully furnished apartment.

Another option is that because Rolla is so cheap and breaking your lease might cost about the same as 3-4 months rent (including moving fees, the pain in the ass of trying to find somewhere to store your stuff, etc.) just keep your stuff in your place, and pay to keep it with all of the money you make doing the co-op. Just have someone check in on the place once in awhile.