Development of an Integrated Design Environment for Space Satellite Structures

Space satellite design generally involves multidisciplinary collaboration processes, such as structural, heat transfer and electrical design processes, aimed at fulfilling various functional requirements that are subject to stringent weight and spatial limitations. This paper discusses a practical application of a systematic design optimization approach to the design of a small satellite called “Micro-LabSat,” in order to obtain optimal solutions that take into account such multidisciplinary design factors. The satellite design problem has two sub design problems, a component arrangement problem and a structural design problem, and the features of these two problems are entirely different since the component arrangement problem involves discrete design variables such as the positions of the components, while the structural design problem has continuous design variables such as the dimensions of the parts. Therefore, a bi-level optimization procedure is applied. First, two sublevel optimization problems for the sub design problems are solved. A two-phase optimization procedure that uses genetic algorithms and SQP (Sequential Quadratic Programming) is applied to the component arrangement problem, and SQP is applied to the structural optimization. Then, the satellite-level optimization problem that considers all factors, including both the component arrangement and structural problems, is solved using the sublevel optimal solutions as initial points for optimization. The bi-level optimization scheme presented here provides an efficient search procedure, and offers optimal solutions in short calculation times.