NASA Successfully Deploys Tennis Court-Sized Sunshield on James Webb Space Telescope

The James Webb Space Telescope (JWST) is a large infrared telescope developed via a partnership between NASA, the European Space Agency, and the Canadian Space Agency. The telescope, launched last month on Ariane flight VA245, is equipped with a 6.5-meter mirror that gives it a light-collecting area around 5.6x larger than the Hubble Telescope.

The James Webb Space Telescope team has successfully deployed the telescope's 21-meter (70-foot) sunshield, marking a key milestone in prepping the JWST for operations, according to a Tuesday memo issued by NASA.

Per the release, the five-layered sunshield was folded to fit inside an Arianespace Ariane 5 rocket’s nose and remotely launched on December 28, 2021–three days after the JWST launch.

At full length, the five-layered sunshield rivals the size of a professional tennis court.

"This is the first time anyone has ever attempted to put a telescope this large into space," boasted Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate.

"Webb required not only careful assembly but also careful deployments," the NASA official added. "The success of its most challenging deployment–the sunshield–is an incredible testament to the human ingenuity and engineering skill that will enable Webb to accomplish its science goals."

On Jan. 4, 2022, engineers successfully completed the deployment of the James Webb Space Telescope’s sunshield, seen here during its final deployment test on Earth in December 2020 at Northrop Grumman in Redondo Beach, California. The five-layer, tennis court-sized sunshield is essential for protecting the telescope from heat, allowing Webb’s instruments to cool down to the extremely low temperatures necessary to carry out its science goals.

© NASA/Chris Gunn

The sunshield is designed to protect the JWST from light and heat emitted from the Sun, Earth, and moon, and is made up of plastic sheets that are as thin as a human hair, but provide the telescope with protection on the order of over SPF 1 million.

"Unfolding Webb’s sunshield in space is an incredible milestone, crucial to the success of the mission," asserted Gregory L. Robinson, Webb’s program director at NASA Headquarters.

"Thousands of parts had to work with precision for this marvel of engineering to fully unfurl, he added. "The team has accomplished an audacious feat with the complexity of this deployment–one of the boldest undertakings yet for Webb."

The tensioning of the sunshield occurred at 11:59 a.m. ET on Tuesday, and required the use of 70 hinge assemblies, around 400 pulleys, eight deployment motors, 90 individual cables, and 139 of the JWST's 178 release mechanisms, according to NASA.

The JWST, humanity's largest and most complex space science observatory, will undergo further operations over the next several month to complete its setup.

These efforts include the deployment of the telescope's secondary mirror and primary mirror wings, as well as the alignment of the JWST's optics and calibration of its instruments.

The JWST is scheduled to reach its final orbit toward the end of January and, after a battery of testing, should during the summer begin beaming back to Earth images from the earliest days of our universe.