Visions of missile defense have long centered on missile interceptors or lasers, occasionally included the radar "eyes" of a system, and usually ignored the computer "brains" that must inevitably control a system. This talk will examine the causes and consequences of the relative invisibility of computing in missile defense research and policy, examining three historical episodes: the Army's push to deploy a missile defense from 1957-63, the "Safeguard" and "Sentinel" deployment proposals of the late 1960's, and the "Star Wars" controversy of the 1980's. I argue that the problems of missile defense have been defined and tackled in ways that do not merely reflect technical realities. Rather, assessments of missile defense also reflect the social status of some scientists - and the non-status of others - as experts on missile defense. In particular, this talk will show how the contested status of computing as a profession and as a science has shaped assessments of missile defense, and conclude by considering some implications for today.