When the last sail of the sunshine on the Webb’s telescope – made of a thin polyamide called Kapton – stretched according to plan and completed a five-layer diamond formation, the great relief of all the technicians on Earth was known.
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The maneuver has been pre-programmed, rehearsed and tested countless times. But it was still a nerve-wracking spectacle. Tensioning the sails was the most complicated part of the whole unpacking process.
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“Webb’s sunshade kit includes 140 release mechanisms, approximately 70 hinges, eight distribution motors, bearings, springs, gears, approximately 400 pulleys and 90 cables with a total length of 400 meters.” describing system specialist Krystal Puga, who works for Northrop Grumman, one of NASA’s main suppliers.
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Exciting tension
The process of unpacking the shields began on December 28, and not everything went according to plan. Each part of the process has a well-defined temperature range at which it can be performed. And operators had to adjust the schedule to cool or heat key components.
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You can see all the unpacking steps in our video at the top of the article.
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When the shield anchor sensor did not indicate a successful interlock, it looked like that’s another problem. “However, secondary and tertiary sources have indicated that development has taken place,” said specialist Patrick Lynch on the NASA blog. “And the temperature data also confirmed that the shield had deployed.”
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The shield has the shape of a dragon and measures 21 meters in length and 14 meters in width, so it would roughly fit on a tennis court.
The outer layer of the shield, which will be the only one to face direct sunlight, is 0.05 millimeters thick, the other four are even thinner, about the thickness of a human hair. Together, they will protect scientific instruments from the sun’s heat. The telescope will face the sun. On the “hot” side of the device, the temperature can rise up to 110 degrees Celsius, the other side, where all the measuring instruments are, must keep the temperature below -223 degrees Celsius for successful operation.
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So far, the latest advancement in unpacking the telescope is the careful opening of the insulation of the instruments in the upper structure of the telescope, which will allow them to cool down.
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The expansion will continue in the coming days. All that remains is “only” the layout of the wings of the main mirror and the subsequent calibration of all mirrors and instruments. You can check the current status on the NASA website.
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No repairers, no mistakes
“This space mission is at the level of the Apollo mission or the space shuttle launch,” emphasizes Greg Robinson, head of the Webb Telescope program. “Thousands of people have been preparing for this mission for two decades. Many have dedicated their entire careers to this mission. ”They all hope that there will be no failure at a crucial stage – sometimes internally referred to as“ a month of horror ”or“ 29 days on the brink ”.
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We have 300 points where the whole mission can fail. And when you’re 1.5 million miles from Earth, you can’t call a repairman.
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“The whole process has 50 complex steps. And there are 178 mechanisms that have to work to make things go according to plan, ”explains Mike Menzel, who heads the technical section of the Webb Telescope. “The dismantling of the Webb Telescope is without a doubt the most complicated space activity we have ever attempted.”
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Shot from testing the five-layer sunshine of the Webb Telescope in NASA laboratories.
“There are no second attempts at the space telescope. We have 300 things that can fail and the whole mission ends (so-called single point failure item), “Menzel emphasized. “When you’re a million and a half miles from Earth, you can’t call a repairman.”
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Unique location
While the team of operators carefully completes the disassembly of the telescope, it is on its way to its target position. This place is located 1.5 million kilometers from Earth and was not chosen by chance. This is the so-called liberation point L2, which is characterized by balancing the gravity of gravity and centrifugal forces in a system of two bodies. In this case, the bodies are the Earth and the Sun. The telescope will be located at point L2 so that its shield can be constantly shielded from the Sun (and also from the Earth and the Moon).
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L2 pound point scheme
However, the static representation is a bit misleading. In fact, Webb’s telescope will orbit L2 and its real orbit so it will be much more complicated, as the following animation shows.
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The journey to this point takes about a month. Thanks to clever maneuvering in the initial phase of the flight, the Webb’s telescope has enough fuel to correct its position for the next more than ten years and stay in this unique orbit.
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We cannot expect the first images from the Webb Telescope until mid-2022.
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For astronomers – especially those studying the early stages of the universe – the Webb’s telescope is a wonderful gift. Its exciting unpacking is then just the very beginning of the whole adventure.
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What the James Webb Telescope will do
Webb’s telescope will be the most powerful space telescope yet. It should oversee the beginnings of our universe, when the first stars and galaxies formed 13.5 billion years ago. According to NASA, it will directly observe a hitherto unseen part of space and time. The device is designed to “see” the infrared light that is now coming to us in this form from the most distant objects.
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JWST (James Webb Space Telescope) will also be used by scientists to study the planets and other bodies of our solar system, to study their origin and evolution, and to compare them with exoplanets, or planets orbiting other stars. At the same time, the telescope will monitor exoplanets, which are located in the so-called habitable zones, and there could be liquid water on their surface. In connection with this, it is also planned to look for possible signs indicating the possible habitability of such bodies.
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To fulfill these tasks, the observatory has a giant mirror with a diameter of 6.5 meters, four scientific instruments and a shield 21 by 14 meters, which will protect the apparatus from the heat of sunlight and keep them in the necessary deep cold. The devices in the equipment are the NIRCam infrared camera, the NIRSpec infrared spectrograph, the MIRI infrared device and the infrared display with the NIRISS spectrograph.
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Scientists are checking the precise adjustment of the telescope’s sensitive sensors.
The large primary mirror consists of 18 smaller hexagonal mirrors, each with a diameter of 1.3 meters and a weight of 20 kilograms. Each is made of beryllium and coated with a gold layer. Beryllium scientists chose this metal because of its lightness and strength. In addition, it maintains its shape even in the low-temperature conditions that the telescope instruments need for proper operation. Gold was chosen for the top layer due to its extremely high light reflectance, over a wide range of wavelengths.
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Update: We have added current information about the mission to the article. We have added information about the orbit of the telescope.
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