Figure 6f – Elevation Drive Detail
Mirror: The mirror is made from 7 mil thick Mylar film on which a thin coating of aluminum has been deposited. The aluminum coating provides a reflectance of approximately 95%. The fact that the mirror is sealed inside the two domes should act to maintain a high level of reflectivity. The mirror is supported around the edges and tensioned by an extruded aluminum right angle ring. The ring was fabricated by roll forming a straight extrusion. The ring is a right angle shape with 1.5 inch by 0.125 inch thick legs. The lacing arrangement shown in figure 6g was used to tension the mirror to about 20 lb/in (the mirror sounds like a bass drum when struck). The ring was then
attached to the Mylar using a polyurethane adhesive. arrangement was cut off.
After the adhesive cured the lacing
The upper and lower domes are bonded to the other leg of the mirror support ring. 3M VHB foam tape was used to bond the domes to the ring on the inside surface of the dome. Then, a 1.5 inch band of Vinyl was tensioned around the outside of the domes at the ring and solvent welded to the upper and lower domes.
November 24, 2002