Analysis And Design Of Space Mirror And Support Structure

One of the most important components of the spacecraft is optical system which is used in collecting all kinds of information. The mirror is the key components of the reflective optical system and increasing the caliber of the mirror is the very effective way to improve the resolution of the space mirror. But there are series problems including the deformation increases caused by the large weight, the deformation caused by the environment with large temperature difference, the increase in launch costs caused by the weight increase. Therefore, we have to get the lightweight structure design and the support structure design in progress to ensure the performance of the optical system stable in the space environment.In this issue, the lightweight space mirror has been designed according to the needs of the users, then import the models of the mirror to the finite element analysis software ANSYS and conducted a detailed analysis including structural analysis and modal analysis of the mirrors. Finally, the mirror with triangular honeycomb panel structure which has high lightweight rate and more stable structure was decided to use in the follow-up research. This paper also calculated the deformation of the mirror caused by the gravity changes and temperature gradient at 4 the most common way of support structure through the CAE software ANSYS, the results of the consideration was analyzed specifically to compare the advantages and disadvantages between the 4 support structures. Finally, the back support structure was determined to used to be the basic model of the optimization structure because of its ability to inhibit the deformation of the mirror.In the optimization process, increased in the number of support points from 3 to 6 through the primary structure and the overall support structure to reduce the deformation of the mirror greatly. By analyzed the deformation of the mirror with different position of support points, identified the best position of support points where the radius of the position of the support points is 60%~70% of the radius of the mirror. In this issue, the relationship between the area of the glue and the deformation of the mirror was defined as the inverse relationship through the analysis of the different deformation with different area of the glue which is used to connect the mirror and the support structure. At the end of this paper, the structure of the mirror was improved in a optimizated way which was used in the HERSCHEL Space Telescope. The conclusion which the deformation of the mirror at optimized structure is more better than previous was drawn. It also proved that this optimized structure was satisfied with the needs of the engineering which is PV≤λ/10(λ=632.8 nm), and make sure the maximum ambient temperature variation less than±3℃, the maximum support structure temperature difference variation less than±3℃, the maximum assembly stress less than 9×10 Pa and the error of the support structure less than 206μm finally. Therefore, the mthod of optimization provide a method and basis to the optimal design about support structure of mirror with larger diameter and it has a high theoretical value and use value in the area of space mirror design.