Survivability and reliability have become important factors in the design of a mission effective Strategic Defense System (SDS) that protects the United States against a ballistic missile attack by the Soviet Union. The SDS must be reliable and responsive in providing this defense. It must also be survivable to counter the Soviet tactics of negating the defense. To ensure an effective, responsive and affordable system, survivability and reliability features must be incorporated in the earliest phases of conceptual design and must be maintained throughout the SDS life cycle. The Engagement Timeline Analysis (ETA) model provides a tool for exploring survivability, reliability and other design trade-offs in the conceptual and preliminary design phases of the system engineering process. This paper presents a unique methodology for the derivation of system survivability and reliability requirements in an SDS design. Evaluations are at the engineering estimate level and are structured to allow sensitivity analyses of pertinent constellation design parameters and operational characteristics. / Master of Science