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New ‘Behind the Webb’ Video Reveals ‘A Perfect Pair’

Credit: STScI/Mary Estacion

The newest video in the “Behind the Webb” series called “A Perfect Pair” provides a look at how two major pieces of the James Webb Space Telescope observatory come together. The video series takes viewers behind the scenes to understand more about the Webb telescope.

The Webb telescope is the world’s next-generation space observatory and successor to NASA’s Hubble Space Telescope. Designed to be the most powerful space telescope ever built, Webb will observe the most distant objects in the universe, provide images of the first galaxies formed and see unexplored planets around distant stars.

Andy Tao, Chief Sunshield Engineer at Northrop Grumman Aerospace Systems, Redondo Beach, California, talks about various elements of the telescope, including the sunshield and the Optical Telescope Element, or OTE. “That’s the part that has the big mirror (segments) and the cameras inside of it,” said Tao. The OTE itself will be mounted on the spacecraft bus, named thus “because it carries the telescope and everything else.” 

The sunshield will deflect sunlight to keep the Webb telescope operating at temperatures near -400 degrees F so the science instruments can see into the most distant galaxies. There are five layers of the sunshield, each separated and held in place by spreader bars and deployable booms. Each layer is the size of a tennis court and is made of Kapton E, a tough plastic film that is only one-to-two-thousandths of an inch thick, about as thick as a human hair.

The Webb telescope’s five ultra-thin sunshield layers are attached, folded and stowed for launch using the Sunshield Full-Scale mock-up (test unit). Northrop is leading the telescope design and development effort for NASA’s Goddard Space Flight Center.

In the video, nine highly trained and skilled personnel worked with the 5,600 pound OTE engineering or test unit and deployed (opened) the sunshield in the cleanroom at Northrop Grumman. The deployment occurs at a much faster rate than it would happen on the actual observatory in space.

Viewers will gain a better perspective on the actual size of the sunshield and OTE and the precision needed to make those placements. “The interfaces that we’re putting together are accurate to a few thousandths of an inch,” Tao said.

The Webb telescope is a joint project of NASA, the European Space Agency and the Canadian Space Agency.

The 3 minute and 59 second video was produced at STScI. The “Behind the Webb” video series is available in HQ, large and small Quicktime formats, HD, Large and Small WMV formats, and HD, Large and Small Xvid formats.

For more information about the Webb telescope, visit: or

To see the Behind the Webb’s “Perfect Pair” video, visit:

Rob Gutro
NASA’s Goddard Space Flight Center