![]() Two days later, the primary mirror will begin to swing two hinged sections into place to create the complete 6.5-metre-wide mirror. Ten days after launch, if all goes well, Webb will move its small secondary mirror to face its giant primary mirror, which will still be folded up. Over the course of four more days, the pallets will open to reveal the five membrane-like layers of the sunshield, and then stretch them and fix them in place, like tightening a sheet over a mattress. Three days after launch, two rectangular pallets are meant to unfold on either side of the observatory. If the sunshield does not deploy properly, Webb’s science will be severely degraded. “The unique aspect about Webb is that it is a cold telescope,” says Hasinger. The telescope launched on a European Ariane 5 rocket. Webb requires frigid temperatures for its optics to be able to pick up the glimmers of distant galaxies and other cosmic objects in infrared wavelengths. The shield’s job is to shade Webb from radiation, and cool the environment from 110 ✬ on the Sun-facing side to –235 ✬ on the shaded side. The entire process is something like a butterfly emerging from its chrysalis, says Günther Hasinger, ESA’s director of science - a very expensive and very complex butterfly that is three storeys tall.įirst and most crucial is the deployment of Webb’s kite-shaped sunshield, which is the size of a tennis court. ![]() The journey to L2 will take 29 days, with more than 300 ‘points of failure’ at which something could go wrong. There, 1.5 million kilometres from Earth, it will always be on the opposite side of the planet from the Sun, looking into the dark reaches of outer space with its sensitive optics shielded from sunlight. Hours later, it was expected to burn its engines to set it on course toward its ultimate destination, a position in space known as the second Lagrange point, or L2 (see ‘Webb’s journey’). “That was half an hour on the edge of my seat,” says Grunsfeld. After separating from the launch vehicle 27 minutes after launch, Webb unfolded its solar panels, a crucial step that allowed electrical power to begin flowing. The Ariane 5 carried Webb on an apparently flawless trajectory into space, which conserves more fuel for the telescope to use for science in the coming years. “I am super grateful for everyone that worked so hard to make it a success.” “I’m feeling very emotional right now after seeing something we’ve all waited for for so long finally happen,” adds Jeyhan Kartaltepe, an astronomer at the Rochester Institute of Technology in New York who has been awarded observing time on Webb. “It’s the beginning of one of the most amazing missions that humanity has conceived.” ![]() “What an emotional day,” said Thomas Zurbuchen, NASA’s head of science, on a webcast from the launch site. The project’s third international partner is the Canadian Space Agency. local time from the Kourou spaceport in French Guiana, on an Ariane 5 rocket provided by the European Space Agency (ESA). The NASA-built Webb launched at 9.20 a.m. Until then, “there’s going to be a lot of nervousness”, says Heidi Hammel, an interdisciplinary scientist for Webb and vice-president for science at the Association of Universities for Research in Astronomy in Washington DC. Not until all the equipment works and the first scientific observations have been made, probably in July, will astronomers be able to relax. Following its launch, Webb will now embark on the riskiest part of its mission - deploying all the parts required for its enormous mirror to peer deep into the cosmos, back towards the dawn of time. The US$10-billion Webb is the most complicated and expensive space observatory in history, and the successor to NASA’s Hubble Space Telescope, which has studied the Universe since 1990. The $11-billion Webb telescope aims to probe the early Universe “Now the hard part starts,” says John Grunsfeld, an astrophysicist and former astronaut and head of science for NASA. ![]() But for Webb to begin a new era in astronomy, as many scientists hope it will, hundreds of complex engineering steps will have to go off without a hitch in the coming days and weeks. The James Webb Space Telescope - humanity’s biggest gamble yet in its quest to probe the Universe - soared into space on 25 December, marking the culmination of decades of work by astronomers around the world.
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