So I started watching Star Wars The Empire Strikes back again earlier today, and one thing that I wondered about (which I'm sure other people have wondered about) is the "Ion Cannon". In the scene leading up to The Battle Of Hoth, they fire the Ion Cannon up at a Star Destroyer and destroy it after about 5 shots. What I want to know is that if it was so easy to take out a Star Destroyer that way, then why don't they just use the Ion Cannon all the time to destroy every big Imperial ship they run into? Or why didn't they use the it to destroy the Imperial Walkers that were attacking them? I want to know what your guys' opinions are about this