I am new to rockets and have just built an Aerotech Mustang that has yet to be flown. I want to cert. L1 this year (not with the mustang) and am confused as to which orginazation I need to join to cert. L1. Do you need to be a member of TRA or NAR or both to cert. L1? If you only need to join one then which is better for high power rocketry?