Within the framework of NASAfrom Télescope spatial James WebbIn latest testing, the 6.5-meter (21-foot-4) mirror was ordered to fully expand and lock into place, just as it would in space. The conclusion of this test represents the team’s final checkpoint in a long series of tests designed to ensure that Webb’s 18 hexagonal mirrors are prepared for a long journey into space and a life of deep discovery. After that, all of Webb’s many moving parts will have confirmed in testing that they can perform their intended operations after being exposed to the expected launch environment.
This video shows the James Webb Space Telescope mirrors through their long series of tests, from individual segments to final tests of the assembled mirror. Credit: NASA Goddard Space Flight Center Michael P. Menzel (AIMM): Producer Michael McClare (KBRwyle): Principal Videographer Sophia Roberts (AIMM): Videographer Michael P. Menzel (AIMM): Video Editor
“The primary mirror is a technological marvel. The lightweight mirrors, coatings, actuators and mechanisms, electronics and thermal blankets, when fully deployed, form a single precise mirror that is truly remarkable, ”said Lee Feinberg, Head of Optical Telescope Elements for Webb at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “This isn’t just the final deployment test sequence the team completed to prepare Webb for life in space, but it means when we’re done the main mirror will be locked in place for launch.” . It’s humbling to think of the hundreds of dedicated people across the country who worked so hard to design and build the Main Mirror, and now to know the launch is so close.
Bringing the test conditions close to what Webb will experience in space helps ensure that the observatory is fully prepared for its science mission a million kilometers from Earth.
The commands to unlock and deploy the mirror side panels were transmitted from Webb’s test control room at Northrop Grumman in Redondo Beach, Calif. The software instructions sent and the mechanisms that work are the same as those used in space. Special gravity compensation equipment has been attached to Webb to simulate the weightless environment in which its complex mechanisms will operate. All of the final thermal blanket and innovative shielding designed to protect its mirrors and instruments from interference were in place during testing.
To observe objects in the distant cosmos and do science that has never been done before, Webb’s mirror must be so large that he cannot fit into an available rocket in its fully extended form. Like an origami work of art, Webb contains many moving parts that have been specially designed to fold into a compact formation that is considerably smaller than when the observatory is fully deployed. This allows it to barely fit into a 5-meter (16-foot) rocket fairing, with little room to spare.
Deploying, operating and tuning its golden mirrors requires 132 individual actuators and motors in addition to complex backend software to support it. Proper spatial deployment is of critical importance to the process of fine-tuning Webb’s individual mirrors into a single, functional and massive reflector. Once the fenders are fully extended and in place, extremely precise actuators at the rear of the mirrors position and bend or flex each mirror to a specific prescription. Testing of each actuator and their expected movements were completed in a final functional test earlier this year.
“Pioneering space observatories like Webb only come about when dedicated people work together to overcome the challenge of building something that has never been done before. I’m especially proud of our teams who built Webb’s mirrors, as well as the complex electronics and backend software that will allow him to see the depths of space with pinpoint accuracy. It has been very interesting and extremely rewarding to see it all come together. The completion of this latest test on its mirrors is particularly exciting given the proximity of the launch later this year, ”said Ritva Keski-Kuha, associate optical telescope elements manager for Webb at Goddard.
As a result of these tests, engineers will immediately move on to Webb’s final tests, which include expanding and then refurbishing two sets of radiators that help the observatory cool, and a full extension and refurbishment of its deployable tower.
The James Webb Space Telescope will be the world’s first space science observatory when it launches in 2021. Webb will solve the mysteries of our solar system, look beyond distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.