Surveying the effect of thermal and mechanical loads on star sensor baffle and its performance

Abstract

Baffles are connected in front of the space cameras and star sensors to prevent the stray lights entering to the electrooptical system. Star sensors are mounted in various places of a spacecraft and imposed to different mechanical and thermal loads. In this research a star sensor baffle with a specified dimension is considered to simulate and analyze the deflections in various conditions. Vibration force from the launcher and gravity force considered as the mechanical load. Launcher vibrant force considered as QSL force and heat load is only considered from the solar radiation and have been modeled for both cold and hot cases. Deflection of the baffle is obtained using finite element method. Heat and mechanical loads are considered both at the launch time and in the orbit. Different materials such as aluminum, titanium, and CFRP composite are selected to do comparison among them. Composite materials are considered in many layer orientation configurations. Monte Carlo method is used to do ray tracing and obtain the efficiencies of the baffle to prevent the stray light entering to the entrance pupil diameter of the camera. Results show that baffles in launch time suffer from some deflections that affect the performance. In the orbit condition, baffles have negligible deformation although the thermal part is dominant. In launch condition, deflection mainly caused from the mechanical load. In orbit condition, deflection mainly caused from the heat load.