NASA has finished and stacked the Sunshield for the Webb Space Telescope and it's now getting ready to test it. Look at this huge thing. That's enough tinfoil to cover a roasted chicken -- if the chicken was the size of Tyrannosaurus Rex. According to NASA, it provides the equivalent of a 1,000,000 Sun Protection Factor.
For reference, sunscreen typically goes from SPF 8 to SPF 80. The shield is necessary to keep the telescope's infrared electronics under 50 Kelvin (-223.15°C.) Without it, the telescope won't work.
The Sunshield on NASA's James Webb Space Telescope is the largest part of the observatory -- five layers of thin membrane that must unfurl reliably in space to precise tolerances. Last week, for the first time, engineers stacked and unfurled a full-sized test unit of the Sunshield and it worked perfectly.
The Sunshield is about the length of a tennis court, and will be folded up like an umbrella around the Webb telescope's mirrors and instruments during launch. Once it reaches its orbit, the Webb telescope will receive a command from Earth to unfold, and separate the Sunshield's five layers into their precisely stacked arrangement with its kite-like shape.
I really hope NASA includes a camera on the top stage because I want to see it getting deployed. It's going to be amazing to see it expanding from a small package into a huge thing, Transformers style. Tip for NASA: That's something that would get you some huge press coverage.