Mission Control is missing from the dock (the rocket icon)

Open Applications folder, locate Mission Control application, drag into Dock. The "rocket" is actually Launchpad. Same solution.

Kappy, thank you so much. It amazes me how simple things are when you know what you are doing. I feel like an idiot! I looked in the book I bought from Apple about Mac OSX Lion and they didn't address this. You are great!