The Design and Construction of the Electronics Package

The reliability program of the Telstar satellite is based upon three factors: component reliability, conservative circuit design with few innovations, and rugged equipment design with quality construction insured by specially trained craftsmen and extensive inspection. Wherever possible, past experience with proven reliable systems provided a guide when applying these factors. In contrast to the approach used in many other satellite programs, the Telstar spacecraft contains a minimum of redundancy. It is also unusual in that the mechanical design encloses most of the electronic circuitry in a hermetically sealed canister filled with polyurethane foam. This prevents readjustment and unit replacement; however, it provides a very rugged unit which is safe from tampering. To further enhance reliability, "white room" conditions were observed during all construction stages. II. COMPONENTS 1 Component reliability, together with redundancy, sets an upper limit on the reliability of the system, for the circuit designer can at best preserve the inherent level of reliability built into the components furnished to him. The selection of semiconductor types was based upon proven reliability in previous systems. A large number of units of a single type 1749