James Webb Space Telescope Fully Deploys Sunshield, to Unfold Secondary Mirror Today

James Webb Space Telescope has completed the complex process of deploying its kite-shaped sunshield. The sunshield, about the size of a tennis court, has five layers. The first three were deployed initially and the last two were done late last night. Deploying all five layers was crucial for the $10-billion (roughly Rs. 74,525 crore) space observatory. The sunshield will keep the telescope cool enough to enable it to begin its quest to capture images of faraway stars and planets.

NASA said the tensioning of the sunshield layers was completed on the 10th day after the telescope, which is set to replace the Hubble, was packed and launched aboard an Ariane 5 rocket. While the completion of this process removes much room for failure, James Webb Space Telescope is set to take about a month to reach its fully deployed state.

“This is it: we’ve just wrapped up one of the most challenging steps of our journey to unfold the universe. With all five layers of sunshield tensioning complete, about 75 percent of our 344 single-point failures have been retired,” the space agency tweeted.

NASA now plans to unfold James Webb’s secondary mirror. It will also livestream the event, starting at 8:15pm IST.

You can also watch the livestream below at the aforementioned time:

The tensioning of the sunshield is a triumph of space engineering. Many initially doubted its success as the design involved use of a lot of motors, gears, cables and other equipment. Engineers devoted years to testing the design and proved sceptics wrong.

James Cooper, James Webb sunshield manager, said previously that the sunshield tensioning phase is challenging because several components interact among themselves.

The sunshield helps cool down the telescope. Temperatures on the Sun or hot side of the shield can reach up to 110 degrees Celsius, while it can be at a low of -236 degrees Celsius. This incredible transition in the temperature is realised through the five layers of the sunshield, spread over nearly six feet.