![](\"http:\/\/spaceweekly.com\/wp-content\/uploads\/2019\/08\/Deployment_test_of_Webb_s_secondary_mirror_small.jpg\")
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\nThe secondary mirror \u2013 visible in the top right corner of the image \u2013 is among the most important pieces of equipment on the NASA\/ESA\/CSA James Webb Space Telescope (JWST) and is essential to the success of the mission.\n<\/p>\n
\nFolded together with the other observatory components during launch, the secondary mirror will be deployed as part of an intricate choreography<\/a> that will bring the observatory to life once in space. When deployed, like in this view, it faces Webb\u2019s iconic honeycomb-like pattern of 18 hexagonal, gold-coated primary mirror segments<\/a>. This primary mirror structure<\/a> is seen in the lower left of the image in its folded configuration, showing only 12 segments.\n<\/p>\n \nOnce the observatory is in space, light from distant stars and galaxies will first reach its primary mirror, which reflect it into a focused beam towards the secondary mirror. From there, the beam is then sent through the \u2018hole\u2019 in the primary mirror structure into the tertiary and fine steering mirrors, and eventually to the four scientific instruments<\/a>, which sit behind the primary mirror in this view.\n<\/p>\n \nTechnicians and engineers recently tested a key part of the telescope unfolding choreography by successfully commanding Webb to deploy<\/a> the support structure that holds its secondary mirror in place. This is a critical milestone in preparing the observatory for its journey to orbit, as the proper deployment and positioning of the telescope\u2019s secondary mirror is critical to perform the mission\u2019s revolutionary science.\n<\/p>\n \nThis successful test<\/a> also provided another demonstration that the electronic connection between the spacecraft and the telescope is working properly, and is capable of delivering commands throughout the observatory as designed.\n<\/p>\n \nNext on the list of key mission milestones is the integration of the James Webb Space Telescope\u2019s two halves \u2013 the telescope element, which comprises the mirrors and science instruments, and the spacecraft and sunshield element \u2013 into its final form as a complete observatory.\n<\/p>\n \nCurrently at Northrop Grumman Aerospace Systems in Redondo Beach, California, Webb is scheduled for launch on a European Ariane 5 rocket from French Guiana in March 2021.\n<\/p>\n \nThe James Webb Space Telescope is an international project led by NASA with its partners, ESA and the Canadian Space Agency. As part of its contribution<\/a> to the project, ESA provides the NIRSpec instrument, the Optical Bench Assembly of the MIRI instrument, the Ariane 5 launcher, and staff to support mission operations at the Space Telescope Science Institute (STScI) in Baltimore, USA.\n<\/p>\n