![]() Tooling balls were placed in these holes for reference purposes during mirror polishing.Below are 15 works that help tell the story of Land art as it has expanded and evolved. The final machining operation was for (30) 0.250"-dia. The mirror surface itself has a specified thickness of 0.098" (2.489mm). Next, the pocket side was finish-milled during a 10-week process.Īfter finish and chemical milling, the pocket wall measures from 0.020" to 0.299" (0.508mm to 7.595mm) thick. Roughing followed a circular path that started in the center and worked outward, removing another 50 to 60 lbs. The segment was heat-treated to relieve machining stresses and then the mirror side was roughed before another heat treatment. Producing the pockets, pads and holes took about 2 months to complete.Īfter pocket milling on the reverse side, a billet weighed about 275 lbs. There are also 22 mounting pads and 249 lightweighting holes. The reverse side of each mirror segment has 600 2.5"-square (63.5mm) pockets. (245kg) beryllium billet was fixtured vertically onto an angle plate on one of the machines. ![]() About 3g (0.106 oz.) of pure gold, total, is deposited on the mirrors.Īs reported in CTE’s May 2007 issue shortly after Axsys Technologies Inc., Cullman, Ala., completed production of the mirror segments, Axsys purchased eight Model HS6A horizontal machining centers from Mitsui Seiki USA Inc., Franklin Lakes, N.J., to machine the segments.Īccording to the machine tool builder, machining began when a 540-lb. Once polishing is completed for each segment, a 100nm-thick coating of gold is applied via vacuum vapor deposition to improve the mirror’s ability to reflect infrared light. Each hexagonal-shaped segment measures about 1.3m (4.2') across and weighs about 40kg (88 lbs.). The mirror segments are made of ultralightweight beryllium and will unfold and adjust to shape after launch, NASA reported. measure the physical and chemical properties of planetary systems and investigate the potential for life in those systems.observe the formation of stars from the first stages of the formation of planetary systems and.determine how galaxies evolved from their formation.Search for the first galaxies or luminous objects formed after the big bang.The stated mission goals of the JWST are to: Technicians perform optical tests on the James Webb Space Telescope. ![]() (7.9') Hubble Space Telescope, the JWST will have nearly three times higher resolution in the infrared. ![]() (2.4') secondary mirror, and, compared to 2.4m-dia. The infrared telescope has a 6.5m (21.3') primary mirror and a 0.74m-dia. Each segment required almost a year to process, including 6,600 hours of machining time, heat treatment and inspection. Although the James Webb Space Telescope isn’t scheduled to be launched on an Ariane 5 rocket from French Guiana until October 2018, NASA announced that the 18th and final primary mirror segment was recently installed on what will be the biggest and most powerful space telescope.
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