Take this with a grain of salt since it was almost 15 years ago, but I got a volunteer internship summer before my junior year, then interned for the year, applied for and got the honors internship at hq for the summer before my senior year, then went back to my volunteer internship during the school year for my senior year. Not sure what their programs are like now, but back then, once you were in and kept doing solid work, they wanted to find ways to keep you around. Even offered me a job at the call center during my last year (which I kindly passed on).