Letters from Bootcamp.

We have been together for 3 years. Although, 2 of those years were long distance. We have just started getting used to having a normal relationship : seeing each other all the time, going on dates, enjoying life together. I knew going into the military was something he's always wanted to do, I just never thought much of it. Now its 2 weeks until he leaves for boot camp. He won't be able to bring anything with him; just the clothes on his back. We will only be able to communicate by letters, and who knows when he will have time to send one. Will our relationship stay intact after 13 weeks with little to no contact? Will a few Letters from Bootcamp be enough?