Deign Of Deployable High-resolution Camera For Earth Observation 3U CubeSat

Micro-nano satellite optical remote sensing is becoming one of the current research and development hotspots in the field of aerospace remote sensing due to its low cost,small size,and strong flexibility.However,the limitation of the volume resources of the tiny platform is also the main constraint to achieve high spatial resolution remote sensing.For this reason,this paper explores the high-resolution space camera optical system that can be quickly and accurately deployed and is suitable for 3U CubeSat.First,the development status of micro-nano satellite ground-to-ground optical remote-sensing cameras is introduced,and the research significance and research goals of this paper are clarified.According to the requirements of developing a 2m ground-resolution remote sensing camera for the 3U CubeSat platform,the index parameters are determined.A two-mirror structure suitable for expansion is selected,the initial structure is calculated according to the primary aberration conditions,and an optical system that meets the requirements of the index is obtained after optimization.Then,the aperture schemes of the deployable primary mirror are compared.The cross-shaped four-rectangular sparse aperture structure is determined.The sub-aperture shape is optimized based on the pupil function and MTF distribution to obtain an aperture structure with balanced imaging performance in all directions.Then,the processing and assembly tolerances are allocated according to the tolerance sensitivity,and the optical machine design scheme that can be quickly deployed is given in detail.Through mechanical simulation,the design was improved and the reliability was verified.The focal plane position pre-adjustment was introduced to reduce the effect of gravity release on the imaging performance of the optical system.The pre-adjustment amount and the repeatability accuracy requirements of the positioning mechanism were calculated by combining tolerance allocation and mechanical simulation.Finally,modal analysis shows that the remote sensing camera can work stably in the launch and space mechanics environments.The design scheme has certain feasibility,which lays the foundation for the development of prototypes and the development of practical loads.