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Being "Secondary" is Important for a Webb Telescope Mirror
From the collection of NASA Image and Video Library. Free to download, adapt and use — no permission needed.
About this work
NASA release July 19, 2011 <b>Click here to learn about the <a href="http://www.jwst.nasa.gov/" rel="nofollow"> James Webb Space Telescope</a></b> The secondary mirror (shown here) was polished at the L3 Integrated Optical Systems - Tinsley in Richmond, Calif. to accuracies of less than one millionth of an inch. That accuracy is important for forming the sharpest images when the mirrors cool to -400°F (-240°C) in the cold of space.
NASA Image and Video Library’s own descriptionCredit lineBeing "Secondary" is Important for a Webb Telescope Mirror. NASA/GSFC, 2017-12-08. Public domain. ID: GSFC_20171208_Archive_e001823.
