Science & Technology

NASA’s Webb Space Telescope is ready for Sunshield deployment and cooldown

Credits: NASA’s Goddard Space Flight Center Conceptual Image Lab

In the first major of Webb structure Deployment Completed and of the observatory Expandable tower assembly expanded, Take a step back to learn more about Webb’s sunshield. Observatory Project Scientist Michael McElwain, NASAGoddard Space Flight Center provided these ideas:

“The Webb telescope and scientific instruments are ready to go into the shade and never see direct sunlight again. One of Webb’s unique design features is passive Cooling with a 5-layer sunshield to reach the telescope’s operating temperature of 45 Kelvin (-380 degrees) Fahrenheit). The giant awning, when unfolded, is about 70 x 47 feet (21 x 14 meters), or about the same size as a tennis court. The shape and size of the awning was determined so that the telescope could always cover 40% of the sky within the field of view and be observable anywhere in the sky for 6 months. This innovative architecture allows the sensitivity of the Webb to be limited by the natural sky background (mainly the zodiacal light) rather than being compromised by the thermal light of the observatory itself at all wavelengths shorter than 15 microns during the mission. increase.

“For launch, the sunshield was folded like a parachute and housed in a front and rear unitized pallet structure (UPS). Both telescope and sunshade support structures are Ariane 5 fairings. They are mechanically connected to each other and connected to a spacecraft bus to fit inside and withstand a dynamic launch environment.

Webb telescope deployment sequence

After the launch, Webb will perform a complex deployment sequence on its way to the second Lang Range Point (L2) for the first month in space. Credits: NASA, ESA, CSA, Joyce Kang (STScI)

“There are 50 Major developments This transforms the Webb from a stored launch configuration into an operational observatory. The sunshield deployment sequence began with a front-to-back deployment in which the UPS was mechanically released from the telescope and motorized down into place. The telescope and scientific instruments attached to the deployable tower assembly were then mechanically released and lifted. There is a momentum flap attached to the end of the rear UPS, which is released and placed. The function of this flap is to balance the sun pressure of the deployed awning. The awning cover is released by the contraction of the membrane release device, rolling out of the way and preparing the system for the deployment of the awning layer. The telescope’s mid-boom is sequentially pushed out of the spacecraft bus perpendicular to the telescope’s line of sight, pulling the folded stack of shade layers into a final, yet untensioned configuration. Finally, each shade layer is tensioned where it begins with the layer facing the sun first and ends with the layer facing the telescope. Deployed Sunshields initiate rapid cooldowns of telescopes and scientific instruments, while onboard heaters within scientific instruments are used to control those cooldowns and prevent contamination.

“These steps have been tested on the ground and operational rehearsed at the Mission Operations Center, but these important activities must be performed for the mission to succeed. Best wishes for our team. Put it in and stay cool, web! “

– Michael McElwain, NASA’s Goddard Space Flight Center Webb Observatory Project Scientist

NASA’s Webb Space Telescope is ready for Sunshield deployment and cooldown NASA’s Webb Space Telescope is ready for Sunshield deployment and cooldown

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