Launching “the most sophisticated space science telescope ever constructed” into space is a complex process, and testing is a huge part of it. The James Webb Space Telescope‘s intricate hardware and technical systems must endure both the vibrations of take-off and the extreme cold of space. JWST Program Director Eric Smith explains via NASA.gov:
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“Webb has many interconnected parts of different stiffnesses. All those parts – including the folded, stowed instruments and mirrors – have to survive launch at room temperature. These elements must then all come together seamlessly in extreme cold to form perfect optical images. All materials change shape as they cool. A flower blossom, a marshmallow, even some metals, will shatter or break if hyper-frozen and dropped onto a hard surface or bent.”
“All of Webb’s components, once assembled, must cool and move in precisely the right way so that the ultra-fine optical tolerances are met when everything is cold. Think of being able to repeatedly parallel park your car and know the position of your back bumper to within a 10th of a diameter of a human hair. That’s how accurate we must be in knowing the position of our mirror surfaces.”