 James Webb Telescope Completes Cryogenic Mirror Test |
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 Jul 30 2010, 11:43 AM
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 Thinker Group: Members Posts: 27126 Joined: 22-April 04 From: 245 Green St., Royersford, PA, 19468 Member No.: 8  |
http://www.spacedaily.com/reports/James_We...r_Test_999.html
Six James Webb Space Telescope beryllium mirror segments completed a series of cryogenic tests at NASA’s Marshall Space Flight Center in Huntsville, Alabama. During testing, NASA contractor engineers subjected the mirrors to -415 degrees Fahrenheit, measuring in extreme detail the shape of the mirror changes as it cooled. NASA will ship the mirror to Redmond, California for final room temperature surface polishing. Using those surface error measurements, NASA will then polish each segment to the opposite value of the observed surface error. When the mirror goes through the next round of cryogenic testing, it should distort into a perfect shape. The Marshall facility is the world’s largest X-ray telescope test facility and a unique site for cryogenic clean room optical testing. The next mirror set is due to arrive in August. Marshall will cryogenically test each of the 18 James Webb mirror segments twice, once with bare polished beryllium and then again after applying a thin gold coating. This will ensure that the mirror will maintain its shape in space. The cryogenic test gauges how each mirror changes temperature and shape over an operational temperature range in space. This helps predict the infrared image quality and data processing adjustments needed. The mirrors and instruments will stay cold to allow seeing the infrared light they reflect. Warm objects give off infrared light, or heat. If the mirror is too warm, we may lose the distant galaxies’ faint infrared in the infrared glow of the mirror itself. Thus, the mirrors will operate around -379 degree Fahrenheit. The James Webb will give clues about the formation of the universe and evolution of our own solar system. This will stretch from the first light after the Big Bang to star system formations capable of supporting life on Earth-like planets. |
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Jul 30 2010, 12:06 PM
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 Mr. Fix-it Group: SuperMods Posts: 15451 Joined: 14-March 05 From: Atlanta, GA (metro-west) Member No.: 166 |
Can't wait for IT'S first light photos!!!
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Jul 30 2010, 12:21 PM
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 Peanut Butta samich Group: Members Posts: 7121 Joined: 22-April 04 From: Rochester, NY Member No.: 24 |
Tell me about it. Can't wait!
Tim- |
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| Lo-Fi Version | Time is now: 9th September 2010 - 02:43 PM |