I am currently working a student co-op position at a company. It's like an internship, except I take time off of school to work full-time for the company. This is intended to be three semesters of work, interspersed with semesters of classes as appropriate. I've worked the past summer and the current fall semester, will be taking classes in the spring, and will return to the company in the summer. This is an official University program.
When I began work in the summer, the official paperwork that I signed covered my employment through the end of the fall (current) semester. I was told that I would receive a second job offer for the following summer, because that's the way they had to make the paperwork happen. I was assured that this does not mean my employment for the summer was in question.
As I prepare to register for my upcoming classes, I feel that I need a more concrete guarantee of my summer employment, because in case that rug were to be pulled from under my feet, it would affect the next couple semesters of schoolwork.
I don't think that they consider me to be invaluable or otherwise "not worth" re-hiring. I have worked hard and earned respect from my boss and coworkers. Further, they have an obligation to the University to carry out three terms of employment, unless they can justify a reason for firing me; however, I don't think that obligation is legally-binding, and I would just feel more comfortable with some assurance that my employment for the upcoming summer were secured.
What is the best way to approach the company in order to request confirmation that I will be re-hired in the summer?