With the end of the year just days away, we're excited to announce #NASAWebb has cleared one of its most important milestones to date. Its 5-layer sunshield has been successfully deployed & tensioned into the same configuration it will have in space! https://go.nasa.gov/3mtYG6J 

Webb is now in its final series of deployment and checkout tests before the observatory is packed for shipment to French Guiana for launch on an @ArianeGroup Ariane V rocket. These tests verify that Webb will survive the launch environment, then deploy perfectly when in space.

This specific test involved turning on and moving 139 different actuators and 8 motors along with thousands of other components to unfold and stretch the five membranes of the sunshield into its final taut shape.
#JWST

This is the last time the James Webb Space Telescope’s sunshield will be fully unfurled and tensioned on Earth.
Following this test, all 5 layers will soon be perfectly packed and folded back up which takes about 2 full months!

This animation shows where Webb will be positioned in space, and how the sunshield will always contend with a bright sun that never sets! By keeping its sensors and mirrors in the shade, they are much more able to detect faint thermal signatures humans have never seen before.

Nearly three months ago (pictured) Webb was exposed to a simulated launch environment in testing chambers. Now Webb is performing a full run of deployments and movements that it will do once in space in the very same order. Launch, shake, rattle, and then unfurl and deploy.

Testing thoroughly, while keeping the spacecraft safe requires thoughtful planning, and careful execution. By monitoring the deployment and tensioning of each individual layer, Webb technicians help ensure that once on orbit, they will all function flawlessly.