NJEMT
I will do my best to clarify. Out of the 6 people in my school that are M1s that are AF HPSP (and i'm not including the one person who was prior AF), only one of them was able to go to COT before our first year. So, this summer he is going to School of Aerospace Medicine Orientation Course. You have to do 4 ADT's. For me and my classmates, we will do COT this summer, I will do SAM Orientation Course next year, and then 2 rotation in years 3 and 4 for those ADTs. Now, you can do that, or you can do 3 rotations. It really depends on what you want. I'm certain I want flight surgeon and eventually to go to SAM for real. My ADTs in 3rd and 4th year I hope will be at Travis and Andrews, but we shall see.
It is NOT a big deal to do COT after your first year. The only reason why you CAN'T do it before your first year is if your application and acceptance aren't done in time. So I would say that your chances of doing COT this summer are slim, especially since I have already received two email confirming my attendance and requesting my mode of transportation.
Good luck with your second board!!! I hope this helped.