Described as humanity’s greatest engineering achievement yet, the James Webb Space Telescope has reached its target, about half a million miles behind our planet. After 20 years of development, $10 billion spent, and 14 days of perfect hi-tech origami in space, the James Webb Space Telescope (JWST) is now completely in place.
Following the successful launch of JWST’s Ariane 5 rocket from the Guyana Space Center on Christmas Day in French Guiana, engineers began remote control of 50 moving parts and 178 release pins. Everything had to happen in order and correctly for Webb to be up and running. And these processes were finally completed successfully.
On Monday, January 24, after 30 days of space travel, Webb arrived at his final destination. Although the project, which can be defined as a science dream, has not been fully realized yet, it can be said that every next step will bring this dream a little closer.
What Next?
Webb is the largest and most advanced space observatory ever built. About 100 times stronger than Hubble, Webb is the size of a 70-metre tennis court. Its massive six-and-a-half-metre primary mirror (Hubble’s primary mirror is about two and a half meters tall) is made of super-strong beryllium and consists of 18 hexagonal segments.
Each part is plated with gold, perfect for reflecting infrared light. This is the biggest difference between Webb and Hubble. Unlike Hubble, which looks at the universe in visible and ultraviolet light, Webb will capture the old, long infrared light. This, combined with its larger mirror, means that astronomers can look back in time in a way they couldn’t before.
O A “Time Machine”
All telescopes can be interpreted as a time machine. The light from every single star you see is actually ancient and comes from far away to get here. Even the light of the sun takes 8 minutes and 20 seconds to reach our planet. The brightest star in the night sky, Sirius is 8.6 light-years away. This means that its light takes 8.6 years to reach your eyes at a speed of about 300,000 kilometers per second.
Every photon Webb will detect is actually ancient light, but since it is an infrared telescope it will detect the oldest, farthest light. Infrared light is electromagnetic radiation with wavelengths longer than visible light, so it cannot be detected by the human eye.
13.8 billion years ago, just after the Big Bang, when the first stars and galaxies formed, the earliest light in the universe was stretched out by the expansion of the Universe. Therefore, it is dark red in color. In fact, it is so red that it falls completely from the visible light spectrum and into the infrared spectrum.
Webb will be able to study these first stars and galaxies several hundred million years after the Big Bang, something no other telescope has been able to do until now. This was exactly the purpose of Webb’s founding.
You can track the current location of the Webb telescope. Although too small and dim to be seen with the naked eye, it is currently located a little east of the Orion Belt, in the constellation Monoceros. Webb will always be on the night side of our planet so he can always see deep space clearly.
Webb is positioned from Earth at what is known as the second Lagrangian point (L2). This point is a very important position in space relative to Earth.
L2, named after an Italian mathematician, is a place on the far side of the Earth from the Sun, about four times the distance from the Earth to the Moon, where the gravity of the Earth and Sun combine to form a relatively stable position. gravity balance point.
This is a location where Webb can always keep the Sun, Earth and Moon behind him, flipping the solar panels back while his powerful mirror is shielded from sunlight by five tennis court-sized sunshield panels. L2 is also a very advantageous point as it is close enough to Earth that we can communicate easily.
Arianespace/NASA/ESA Webb is quite different from most space telescopes, including Hubble, in orbiting the Earth and peering into space. Hubble is corrected for an optical anomaly by Space Shuttle astronauts in 1993, a few years after launch, while Webb is positioned too far to correct if something goes wrong.
Webb won’t be there alone, however: the European Space Agency’s Gaia 3D star mapper is currently in L2 orbit, and the Rome Space Telescope will join them in 2027.
After the mechanical unfolding of the observatory was completed, the engineers began to align the mirrors. By removing each of the 18 primary mirror segments and the secondary mirror from the launch pattern, they adjusted the curvature of each mirror segment to adjust the overall shape of Webb’s primary mirror.
NASA says it may take until April 24 to align 18 hexagonal gold-plated beryllium segments to create Webb’s primary mirror.
Webb Operations Project Scientist Jane Rigby of NASA Goddard Space Flight Center said at a press conference in January, “This doesn’t come out of the box ready and the first images will be ugly – blurry.” Engineers will basically need to work on 18 images that need to be combined into a single telescopic image.
It will be meticulous work. “We start by closing the mirrors in millimeters and then move them to align to a space smaller than the size of a Coronavirus — 10s of nanometers –” said Rigby. “It’s a very meticulous process that takes time.”
It will take about two months for engineers to guide Webb towards some bright stars to properly align and focus the telescope when this process ends in mid-March. Webb’s four key science instruments will then be tested and commissioned as they cool to -370 degrees Fahrenheit/-223 degrees Celsius.
NASA notes that the first flashy photos from Webb are not expected to arrive until about five months after launch, after commissioning ends in late May according to current timelines.
“We want to make sure that the first images the world has ever seen do justice to this $10 billion telescope,” says Rigby. While he hasn’t commented on what exactly these impressive images will look like, we can expect to see Webb’s deep infrared overlays on classic Hubble images such as the Horsehead Nebula and the Pillars of Creation. This, to sum up, seems to be true in late May or early June.
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