Design and optimization for main support structure of a large-area off-axis three-mirror space camera

Area of Science:

• Optical Engineering
• Mechanical Engineering
• Aerospace Engineering

Background:

• Large-area, off-axis three-mirror anastigmat (TMA) space cameras require high static and dynamic performance.
• System weight reduction is a critical factor in space camera design.

Purpose of the Study:

• To design a lightweight truss support structure for TMA space cameras.
• To optimize the structure for excellent static and dynamic performance.
• To validate the design through finite element analysis (FEA) and experimental testing.

Main Methods:

• Topology optimization using the solid isotropic materials with penalization (SIMP) method for truss structure design.
• Consideration of gravity effects along X, Y, and Z axes in optimization.
• Weighted optimization of truss size to minimize vibration response without compromising mechanical performance.

Main Results:

• Achieved optimal topology for the truss structure considering gravity.
• The final truss structure demonstrated excellent static performance, with relative optical axis angle < 5.3 arcseconds.
• Dynamic performance met requirements: acceleration RMS value for fold mirror mount points < 20 g, primary frequency 97.2 Hz.

Conclusions:

• The topology optimization and weighted size optimization method is reliable for designing TMA space camera truss structures.
• The developed truss structure ensures superior static and dynamic performance for space cameras.
• The optimized design contributes to lighter and higher-performing space optical systems.