Science.-Webb telescope’s tennis court parasol passes final tests
MADRID, 21 Dic. 2020 (Europa Press) –
The size of a tennis court, the fully assembled NASA Webb Space Telescope’s five-layer sunshade has successfully completed final tension and deployment tests.
This milestone brings the observatory one step closer to launch in 2021.
“This is one of Webb’s greatest accomplishments in 2020,” Alphonso Stewart, Webb Implementation Systems Leader at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, said in a statement. “We were able to precisely time the deployment motion in a very slow and controlled manner and maintain its critical comet shape, which means it is ready to perform these actions in space.”
The sunshade protects the telescope and reflects light and background heat from the Sun, Earth, and Moon out into space. The observatory must be kept cool to achieve breakthrough science in infrared light, which is invisible to human eyes and feels like heat.
In the shade of the parasol, Webb’s innovative technologies and sensitive infrared sensors will allow scientists to observe distant galaxies and study many other intriguing objects in the universe.
Maintaining the shape of the parasol is a delicate and complicated process.
The Kapton polymer coated membranes of Webb’s parasol were fully deployed and tensioned this December at Northrop Grumman in Redondo Beach, California. Northrop Grumman designed the observatory parasol for NASA.
During the tests, engineers sent a series of commands to the spacecraft’s hardware that activated 139 thrusters, eight engines, and thousands of other components to deploy and stretch the five parasol membranes into their taut final form. A challenging part of the test is deploying the sunshade in Earth’s gravitational environment, which causes friction, unlike material that unfolds in space without the effects of gravity.
For launch, the sun visor will be folded around two sides of the observatory and attached to an Ariane 5 launch vehicle, provided by the European Space Agency.
In this test, two paddle structures that hold the parasol upright are bent down, then two huge “arms” (known as the middle boom assembly) of the parasol are slowly extended outward, pulling the folded membranes together. with them to resemble the synchronized movements of a very slowly choreographed dance. Once the arms were locked in their horizontal position, the parasol membranes were successfully individually tensioned starting with the bottom layer, separating each in its fully deployed form.
The large sunshade divides the observatory into a warm side facing the Sun (approximately 85 degrees Celsius) and a side facing cold space (minus 197 degrees Celsius) made up of optics and scientific instruments. The hood will protect the observatory’s optics and sensors, so they will remain at extremely cold temperatures to conduct science.
“This milestone indicates that Webb is on track to be launch ready. Our engineers and technicians made incredible progress in testing this month, reducing significant risk to the project by completing these milestones for launch next year,” he said Bill Ochs, Webb project manager at Goddard. “The team is now preparing for final post-deployment environmental tests at the observatory over the next several months before dispatching it to the launch site next summer.”
Webb has passed other rigorous implementation tests during its development, which successfully uncovered and resolved technical problems with the spacecraft. These tests validate that once in orbit, the observatory and its many redundant systems will run smoothly.
The James Webb Space Telescope will be the world’s leading space science observatory when it launches in 2021, according to NASA. Webb will solve mysteries in our solar system, look beyond distant worlds around other stars, and explore the mysterious structures and origins of our universe and our place in it. Webb is an international program run by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.
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