Can he keep me from bringing our daughter to another state even if I am willing to make fair visitation arrangements outside of the school schedule?

My husband is a career military and we have been married for 5 years. However, my ex-husband and I have an 8 year old daughter. We are currently stationed in one state and my ex is from another state. My ex has followed us to all of our duty stations in the last five years. Although we did have joint custody papers drawn up when we divorced, most if not all of the terms have become null and void. (For instance it states, I am to have my daughter Tues. through Sat. and he from Sat. through Tuesday. However, with her now being in school and he living in another town, that' simply not feasible, therefore I keep her Mon through Fri. and he typically gets her 2 weekends a month.) However, my husband has currently come down on orders to report in 2017. My ex is upset and says he doesn't want to go nor does he want me to take our daughter. I have 2 other children at home with my husband. My daughter wants to go. And I of course am willing to work out arrangements with my ex to allow her to visit him on holidays and the summer.