Separated. How would I go about leaving the state with my son?

Okay, my husband and I have been separated for about 6 months. We are planning on getting a divorce when he get's back from Iraq. I live in Missouri and want to move to North Carolina with my son. Is that legal for me to take my son out of state while we are still technically married? Would I need to go to the courthouse and get temporary custody of him until we get the divorce? I don't want my "husband" to freak out and try to file kidnapping charges on me so I want to make sure I have the laws straight.