Mechanical Design and Integration

The Explorer XIII spacecraft was designed to provide a suitable carrier for detectors selected to investigate the micrometeoroid hazard in space. The spacecraft (fig. III-1) is made up of the payload, ABL X248-A5 rocket-motor case, and the Scout fourth-stage structure. The design restraints placed on the payload by the launch vehicle were mainly upper limits as to weight and available space. The final shape of the spacecraft was dictated, to a large extent, by the mission requirements and Scout fourth-stage configuration. During launch the vehicle subjects the payload. to high static, dynamic, and centrifugal stresses which essentially determine the structural design requirements. These environmental conditions are as outlined in chapter VII, section II (see the section entitled "Environmental Test Specifications" for the vibration and shock specifications and the section entitled "Prototype Environmental Test Program" for the acceleration and spin specifications). The limited weight capability of the vehicle necessitated an extremely light-weight design. To minimize the amount of weight required for dynamic balancing, the payload was designed as symmetrically as possible about its spin axis.