The James Webb Space Telescope has begun the process of erecting the sunshield that will keep the spacecraft cool enough to operate, which is one of the mission’s most dangerous tasks. On December 28, NASA stated that spacecraft controllers had begun the multiday process of fitting the sunshield by lowering 2 parts known as Unitized Pallet Structures. NASA stated that one will be on the front, while the other is going to be on the spacecraft’s back. At 1:21 p.m. Eastern, the front structure was secured into place, followed by the back structure nearly six hours later.
In a blog post, NASA stated, “The installation of the pallet structures starts what is going to be at least 5 more days of critical procedures to install the sunshield, a process which will eventually determine the mission’s potential to succeed.” “Webb would be impossible to survey the universe in the manner it was envisioned if the sunshield is not in place to maintain Webb’s telescope and equipment extremely cool.”
The 5-layer Kapton sunshield, which is aluminum-coated is used in the structures. The sunshield will keep sunlight from getting to the telescope and its equipment after it is deployed, enabling them to cool to a working temperature of –233°C. In order for the telescope to work well for infrared observations, it must be kept cool.
The lowering of these structures is simply the beginning of a lengthy procedure that will eventually result in the deployment of the sunshield. The sunshield covers are going to be released the next day after the telescope’s tower is extended, which is slated for December 29. A day later, the booms on the spacecraft’s left and right sides will be extended, and cables will mold the 5 layers into the final shape.
The sunshield deployment process is expected to be finished on January 2nd, according to the mission’s schedule. Before the launch, however, project engineers warned that installing the sunshield was going to be the most difficult part of the JWST’s total commissioning. During a November briefing, Mike Menzel, who is the head mission systems engineer for the JWST at NASA’s Goddard Space Flight Center, remarked, “The sunshield is one of those things that is virtually intrinsically indeterministic.” “The sunshield is a potentially dangerous item.”
At the same briefing, Northrop Grumman’s Krystal Puga, a JWST spacecraft systems engineer, described the sunshield deployment procedure to a “Rube Goldberg machine,” in which one stage activates the next using a combination of wires, pulleys, and motors.
Despite the complexity, she noted that she was certain that the sunshield would deploy as intended. “Over the course of several years, we conducted multiple deployment tests on both small as well as full-sized models,” she explained. “This gives us faith in Webb’s ability to deploy successfully.”