NASA / ESA / CSA-ASC - James Webb Space Telescope (JWST) patch.
Jan 5, 2022
The NASA/ESA/CSA James Webb Space Telescope team has fully deployed the spacecraft’s sunshield in space, a key milestone in preparing it for science operations.
The sunshield – about the size of a tennis court at full size – was folded to fit inside the Ariane 5 rocket’s nose cone prior to launch. The Webb team began remotely deploying the sunshield on 28 December 2021, three days after launch. The five-layered sunshield will protect the telescope from the light and heat of the Sun, Earth and Moon.
The unfolding occurred in the following order, over the course of eight days:
- Two pallet structures – forward and aft – unfolded to bring the observatory to its full 21 m length;
- The Deployable Tower Assembly deployed to separate the telescope and instruments from the sunshield and the main body of the spacecraft, allowing room for the sunshield to fully deploy;
- The aft momentum flap and membrane covers were released and deployed;
- The mid-booms deployed, expanding perpendicular to the pallet structures and allowing the sunshield to extend to its full width of 14 m;
- Finally, the sunshield was fully tensioned and secured into position, marking the completion of the sunshield deployment.
Webb unfolding sequence
The unfolding and tensioning of the sunshield involved 139 of Webb’s 178 release mechanisms, 70 hinge assemblies, eight deployment motors, roughly 400 pulleys, and 90 individual cables totaling almost half a kilometre in length. The team also paused deployment operations for a day to work on optimising Webb’s power systems and tensioning motors, to ensure Webb was in prime condition before beginning the major work of sunshield tensioning.
The world’s largest and most complex space science observatory has another 5.5 months of setup still to come, including deployment of the secondary mirror and primary mirror wings, alignment of the telescope optics, and calibration of the science instruments. After that, Webb will deliver its first images.
The telescope’s revolutionary technology will explore every phase of cosmic history – from within our Solar System to the most distant observable galaxies in the early Universe, to everything in between. Webb will reveal new and unexpected discoveries and help humankind understand the origins of the Universe and our place in it.
Webb’s journey to L2
Webb is the largest, most powerful telescope ever launched into space. As part of an international collaboration agreement, ESA has provided the telescope’s launch service using the Ariane 5 launch vehicle. Working with partners, ESA was responsible for the development and qualification of Ariane 5 adaptations for the Webb mission and for the procurement of the launch service by Arianespace.
Secondary Mirror Deployment Confirmed
Today, Webb teams successfully deployed the observatory’s secondary mirror support structure. When light from the distant universe hits Webb’s iconic 18 gold primary mirrors, it will reflect off and hit the smaller, 2.4-foot (.74-meter) secondary mirror, which will direct the light into its instruments. The secondary mirror is supported by three lightweight deployable struts that are each almost 25 feet long and are designed to withstand the space environment. Specialized heating systems were used to warm up the joints and motors needed for seamless operation.
“Another banner day for JWST,” said Bill Ochs, Webb project manager at NASA’s Goddard Space Flight Center, as he congratulated the secondary mirror deployment team at the Mission Operations Center in Baltimore. “This is unbelievable…We’re about 600,000 miles from Earth, and we actually have a telescope.”
Webb launch campaign highlights
The deployment process began at approximately 9:52 a.m. EST, and the secondary mirror finished moving into its extended position at about 11:28 a.m. EST. The secondary mirror support structure was then latched at about 11:51 a.m. EST. At approximately 12:23 p.m. EST, engineers confirmed that the structure was fully secured and locked into place and the deployment was complete.
“The world’s most sophisticated tripod has deployed,” said Lee Feinberg, optical telescope element manager for Webb at Goddard. “That’s really the way one can think of it. Webb’s secondary mirror had to deploy in microgravity, and in extremely cold temperatures, and it ultimately had to work the first time without error. It also had to deploy, position, and lock itself into place to a tolerance of about one and a half millimeters, and then it has to stay extremely stable while the telescope points to different places in the sky – and that’s all for a secondary mirror support structure that is over 7 meters in length.”
Next Webb will deploy an important radiator system known as the aft deployable infrared radiator (ADIR), which helps shed heat away from its instruments and mirrors.
Webb is an international partnership between NASA, ESA and the Canadian Space Agency (CSA).
Related article:
Sunshield Successfully Deploys on James Webb Space Telescope
https://orbiterchspacenews.blogspot.com/2022/01/sunshield-successfully-deploys-on-james.html
Related link:
James Webb Space Telescope (JWST): https://www.esa.int/Science_Exploration/Space_Science/Webb
Images, Video, Text, Credits: European Space Agency (ESA)/NASA.
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