Honeycomb mirror

[2] The design provides sufficient rigidity for ultra-high-precision optics while reducing the weight of the mirror.

Solid mirrors are not only mechanically cumbersome, but are also difficult to cast and safely cool into a single, large blocks of glass.

Honeycomb designs can reduce the weight of the mirror by as much as 80%.

The bending stiffness of a honeycomb mirror is given by: where E is Young's modulus, h is the thickness of the honeycomb core at the center, and t is the thickness of the upper and bottom plates.

The weight of a honeycomb mirror compared to a solid mirror is: where α, being significantly less than 1, is the relative density of the core compared to the face plate.