zhanism

Hi all, I am playing the campaing game and for some reason, I cant find the technology for missle defenses. They dont appear on my tech tree when I reasearch. I have lazers, and armor and shields, but for the life of my poor ships, I cant find missle defense at all. Am I missing something here? Or is armor and shields all there is against missles? I remember playing a random game that there was some sort of missle defense. Any hel