A deployment (or college, distance running, distance biking, saving for a house, weight management, or any other number of long-term goals) takes a very long time. Unless you have been through it several times in the past, which most of us have not, it is hard and frightening to try to comprehend the enormity of the challenge lying ahead.
Luckily we have the ability to break down these larger goals into smaller more achievable and easier to comprehend milestones. When I go running, I keep the end goal in the back of my mind. However, foremost in my mind is what pace I am keeping for the next mile. I know how far miles are, often I can even see on the road in front of me when that mile will be, and therefore I can take action to pace myself correctly and finish that mile at the given pace. Before the run, I planned out what pace I would like to keep through each mile in order to generate a coherent plan around the entire run. This makes the complex long run into a compilation of many understandable individual miles.
The same is true for larger goals, such as finishing the deployment. The entire year-long deployment could be broken down into three major eras: "Mobilization," "Time Before Leave," and "Time After Leave."
These eras could be further broken down. For instance, I just entered "Time After Leave." As such, I have it broken down into goals I am looking forward to that have been yearly traditions since I was born. Those are Halloween, Thanksgiving, Christmas/New Year's, and then coming home.
So right now I am just making it until Halloween. As such, I have runs, trips, workouts, and other smaller goals that take me to that milestone. Each day I can clearly see my progress towards one of these events. This makes the larger goal of finishing the deployment as productively as possible into a compilation of many simple tasks. It's much easier to take the next step forward when you are working towards a simple, though perhaps difficult, short-term goal.