Medium-sized aperture deployable telescope for microsatellite application

An important research interest on space optics is the ultra-light space telescope technology which is compatible with microsatellite platform. To realize lightweight telescope, one way is to develop deployable telescopes. They not only maintain the capabilities of traditional non-deployable telescopes but also have compacter launch volume and lighter weight and lower cost. We investigate the telescope with accurate deployable structure based on tape springs. Before launch, the secondary mirror support structure with tape springs is folded, and when the satellite is on orbit, the secondary mirror is deployed with the elastic strain energy of folded tape springs. There are mainly three parts in the paper. Firstly, the telescope optics was presented. A Ritchey-Chretien (RC) type optical system with 300mm aperture was designed. The influence of the secondary mirror misalignment on the optical performance was analyzed. Secondly, the deployable telescope structure with tape springs was designed for the RC system. The finite element method (FEM) was used to analysis the dynamics of the unfolded telescope structure. Finally, the deployment precision metering system was discussed.