That sub was supposed to use it's nuke cruise missiles against our navy ships but they weren't accurate enough so they would move the ships off our coast and aim for bigger targets if the ballon went up...
That big "crack" in the forward portion of the sail is actually a hinged section that unveils a big radar antenna to guide the missiles...
I had a chance in the early 90s to board a Russian cruiser and destroyer in Boston Harbor and it was distrubing to see how crude these ships are when compared to their western counterparts. It's amazing that they didn't leak
but I'm sure they were still deadly (to us and them)
There's all kinds of cool info on naval ships at
http://hazegray.org if anyone is interested (one of my favorite sites)....
Mike - is the public invited to check it out?