Mechanical design of zoom optical system for deep space exploration

As one of the largest aerospace countries in the world, China’s National Space Administration has officially launched the China Mars Exploration Project in 2016. The zoom lens, in contrast to a fixed focal length lens, has a continuously variable focal length that provides more intuitive information for probing activities. Therefore, it is particularly important to design a zoom lens and use it as a Mars probe imaging payload. In this paper, a zoom system is designed for the climatic environment of Mars and the condition requirements of the lander during transportation work. At the same time, different types of structures were discussed. Finally, a cam rotation mechanism was used in the zoom mechanism. Examining the complexity of the space thermal environment, the thermal characteristics of the system structure will have a great impact on the system performance. To prevent the adverse effects of different thermal expansion coefficients on the system over a wide operating temperature range, select the appropriate materials and the overall structure It is very important to carry out finite element analysis. In this paper, thermal deformation analysis of Aluminum Alloys, Titanium Alloys and Invar Steel materials was performed. The results show that the thermal deformation of Aluminum Alloy materials is maximum at the working temperature of -55°C to +55°C, the thermal deformation of the Aluminum Alloy material is the largest, and the titanium alloy and Invar Steel are relatively small. Finally, the axial displacement is analyzed. The analysis results show that Invar Steel material has the smallest axial displacement. However, considering the weight reduction, it has met the rocket launch requirements. Finally, titanium alloy material is used as the system structural material, and the cam curve is compensated according to the axial displacement.