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→Space Telescopes
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The James Webb Space Telescope will have 18 hexagonal beryllium sections for its mirrors. Because JWST will face a temperature of −240 degrees Celsius (33 kelvins), the mirror is made of beryllium, capable of handling extreme cold better than glass. Beryllium contracts and deforms less than glass - and remains more uniform - in such temperatures. For the same reason, the optics of the Spitzer Space Telescope are entirely built of beryllium metal. | The James Webb Space Telescope will have 18 hexagonal beryllium sections for its mirrors. Because JWST will face a temperature of −240 degrees Celsius (33 kelvins), the mirror is made of beryllium, capable of handling extreme cold better than glass. Beryllium contracts and deforms less than glass - and remains more uniform - in such temperatures. For the same reason, the optics of the Spitzer Space Telescope are entirely built of beryllium metal. | ||
[http://www.jwst.nasa.gov/ Nasa page on the Telescope] | |||