Sunshade Deployment is considered one of the riskiest aspects of the $10 billion mission, one that simply has to work as planned or Webb’s science will be degraded. Extraordinary tests were carried out on the ground to make sure the Deployment would work as planned, but there are no guarantees.
Bill Ochs, NASA’s project manager said that you don’t want to test it too much because the sunshield is so fragile, but we did three or four Deployment and the last one, we were fully successful, we felt really good about it. , said before launch. It only has to work one more time, and that’s in orbit.
On Tuesday, three days after the Christmas Day launch and following two flawless trajectory correction thruster firings, commands were uploaded to rotate the first pallet back down on the forward side of Webb’s primary mirror. The second pallet was rotated into place on the aft side of the mirror later in the day.