Systems and methods for providing mirrors with high stiffness and low inertia involving chemical etching

Abstract

A method is disclosed of fabricating a mirror for use in limited rotation motor systems, said method comprising the steps of providing a mirror structure including at least one wall section, and exposing the at least one wall section to a fluid etching agent to thereby provide chemical milling of the mirror structure.

1 . A method of fabricating a mirror for use in limited rotation motor systems, said method comprising the steps of providing a mirror structure including at least one wall section, and exposing the at least one wall section to a fluid etching agent to thereby provide chemical milling of the mirror structure. 
     
     
         2 . The method as claimed  claim 1 , wherein said mirror substrate includes beryllium. 
     
     
         3 . The method as claimed in  claim 1 , wherein said fluid etching agent includes hydrofluoric acid (HF). 
     
     
         4 . The method as claimed in  claim 1 , wherein said fluid etching agent includes nitric acid (HNO 3 ). 
     
     
         5 . The method as claimed in  claim 1 , wherein said method includes the step of applying a mask to a protected area to prevent etching of the protected area. 
     
     
         6 . The method as claimed in  claim 5 , wherein said protected area is a front reflective surface of the mirror. 
     
     
         7 . The method as claimed in  claim 1 , wherein said method further includes the step of agitating a bath that includes the beryllium structure and the fluid etching agent. 
     
     
         8 . The method as claimed in  claim 7 , wherein said method further includes the step of controlling a rate of agitation of the bath that includes the beryllium and the fluid etching agent to control a shape of the at least one wall section. 
     
     
         9 . The method as claimed in  claim 1 , wherein said mirror structure is removed from the fluid etching agent when the mirror reaches a target reduced weight. 
     
     
         10 . The method as claimed in  claim 1 , wherein said method further includes the step of drawing the beryllium structure from the fluid etching agent at a controlled rate such that the at least one wall section forms a tapered wall. 
     
     
         11 . The method as claimed in  claim 1 , wherein said method provides uniform milling of exposed surfaces of the beryllium structure. 
     
     
         12 . A mirror for use in a limited rotation motor systems formed from the method of  claim 1 . 
     
     
         13 . A mirror for use in a limited rotation motor system, said mirror comprising a backing structure opposite a front of the mirror, said backing structure including at least one wall section having a tapered shape that tapers as the wall extends away from the front of the mirror. 
     
     
         14 . The mirror as claimed in  claim 13 , wherein said backing structure includes beryllium. 
     
     
         15 . The mirror as claimed in  claim 13 , wherein said wall sections are formed by chemical etching. 
     
     
         16 . The mirror as claimed in  claim 13 , wherein said tapered shape of the wall section has a thickness of no greater than about 0.25 mm. 
     
     
         17 . The mirror as claimed in  claim 13 , wherein said backing structure includes a plurality of hexagonally shaped wall sections each of which is tapered as the wall extends away from the front of the mirror. 
     
     
         18 . A mirror for use in a limited rotation motor system, said mirror comprising a backing structure opposite a front of the mirror, said backing structure including features that provide rigidity to the mirror and that have thicknesses that become reduced in a direction away from the front of the mirror. 
     
     
         19 . The mirror as claimed in  claim 18 , wherein said backing structure includes beryllium. 
     
     
         20 . The mirror as claimed in  claim 18 , wherein said features have thicknesses of no greater than about 0.25 mm.