Re-Entry Vehicle Optimization and Synthesis Program

Prior to the detailed design of a ballistic vehicle, it is highly desirable to investigate many combinations of load carrying structure and thermal shield. To realize this goal, an IBM 7090 computer program was recently developed for use in preliminary design at General Electric's Re-entry Systems Department. Needing only the basic vehicle shape and aerodynamic and trajectory data, this program determines structural loads and heat flux throughout the trajectory. Using these data, the minimum weight combination of structural material-configuration and thermal shield is then selected. The program consists of four modules: Structural loads, thermal flux, thermal conductivity, and structural analyses. The structural analyses built into this program consider the common light-weight missile structures, that is, honeycomb sandwich, corrugation-stiffened sheet, waffle-reinforced sheet, and so forth. Minimum weight trends are presented for the corrugation-stiffened and waffle-reinforced shell subjected to re-entry loads of axial compression and external pressure. The comprehensive use of the digital computer in preliminary structural design optimization and synthesis programs is illustrated.