The newest video in the “Behind the Webb” series called “Working Stiff,” takes an inside look at the sunshield on NASA’s James Webb Space Telescope.
Viewers are taken to Mantech Corporation in Huntsville, Alabama, the sunshield manufacturer where they will learn the importance of a catenary, and the how and why the five sunshield layers are kept flat and in shape to resemble a kite in space.
The sunshield will act like an umbrella, keeping the telescope and science instruments aboard the Webb telescope cool by keeping them in the shade and protecting them from the heat of the sun and warm spacecraft bus electronics. It consists of five layers, or membranes, of a material called Kapton, with a shiny silver reflective coating. Each successive layer of the sunshield is cooler than the one below. The heat radiates from between the layers, and the vacuum between the layers is a very good insulator. One big thick sunshield would conduct the heat from the bottom to the top more than five layers separated by vacuum.
Because of its large size, the sunshield is folded up during launch. When the Webb is deployed in space each of the layers unfolds to the size of a tennis court.
The catenaries that provide stability for the sunshield are metal strips that give the membrane its three-dimensional shape. Catenaries stiffen the membranes but allow them to maintain the relative alignment and shape that are so critical to them working together correctly as an effective sunshield. Viewers will see a 34-foot long strip put onto a sunshield membrane in a clean room.
The stiffness of the sunshield is important because each membrane layer edge must line up precisely with its neighboring layers so that no hot edges can be ‘seen’ by the telescope optics, and each membrane must stay taught so that heat reflects out efficiently.
The video series takes viewers behind the scenes to understand more about the Webb telescope, 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 study newly discovered planets around distant stars.
The Webb telescope is a joint project of NASA, the European Space Agency and the Canadian Space Agency.
The 5 minute and 24 second video was produced at the Space Telescope Science Institute (STScI) in Baltimore, which conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy Inc. in Washington. 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: www.jwst.nasa.gov or www.nasa.gov/webb
For more information about the sunshield, visit: http://jwst.nasa.gov/sunshield.html