NASA’s James Webb Space Telescope (JWST) has completed two additional initial steps needed to install its sunshade.
The previous step in the final implementation of JWST’s sunshade was the expansion of Deployable Tower Assembly (DTA) on December 29th. On December 30, Aft Momentum Flap was inserted, followed by the release of the sunscreen.
Aft Momentum Flap is used to equalize any solar pressure hitting the large sunshade. It also helps minimize the fuel consumption of JWST. Just after noon. 9 a.m. EST (14:00 UTC) the hold-down devices were released and a spring drove the rotation of the aft flap to its final position. The process took about eight minutes. An animation of the implementation can be seen here.
Then, the release devices for the protective diaphragm covers enclosing the sun visor were activated. These covers protected the sunshade during launch and while JWST was on the ground. You can see an animation of the process here. An overview of the entire implementation sequence can be viewed James Webb Space Telescope (JWST) YouTube channel.