If you get deployed while attending school, you are allowed to drop the courses as if you never took them and get a refund of your tuition. If your state has TA (Tuition assistance) this should not be a problem. We had quite a few student soldiers in my last unit and the commander allowed the students to leave AT early to return home and take final exams. In most cases as long as you don't abuse the privilege, your chain of command should work with you.