The James Webb space telescope surpassed this Tuesday (4) an important step, by completely opening its thermal shield, a five-layer sunshade, necessary to observe the cosmos, informed NASA.
While the observatory still needs many operations to complete, opening this umbrella was “the most difficult” on the list, admitted Thomas Zurbuchen, NASA’s head of scientific missions in a statement.
Each of the layers of this heat shield is the size of a tennis court and is needed to protect scientific instruments from the heat of the sun. Since Monday (3), each one of them has opened and extended.
The telescope is too big to accommodate a rocket, so it had to be folded back on itself like an origami and deployed in space, an extremely dangerous procedure.
“It’s a very special day,” tweeted astronomer Klaus Pontoppidan, James Webb’s chief scientist. “I think it’s time to realize that soon we may have a fully operational giant space telescope.”
Astronomers around the world were anxiously awaiting the James Webb, the most powerful space telescope, as it will allow us to observe the first galaxies, formed a few hundred million years after the Big Bang.
The observatory was launched just over a week ago from French Guiana and is currently located over 900,000 kilometers from Earth. It heads towards its definitive orbit, 1.5 million kilometers from Earth, that is, four times the distance between our planet and the Moon.
In this location, if any problems arose, it would not be possible to foresee a repair mission.
Its opening, directed from Baltimore, had to be accomplished without a hitch. More than a hundred engineers took turns day and night to ensure that everything went as planned.
NASA broadcast the procedure live over the internet. Since there is no camera aboard the James Webb, the only images available were from the operations control room. The team exploded with joy when the opening was completed.
“Relief”
“The atmosphere is hard to describe. It was an incredible moment. There was a lot of joy, a lot of relief,” Hillary Stock, who is in charge of opening the umbrella at Northrop Grumman, a NASA partner, told reporters. “Everything went well,” he added.
The umbrella measures 20 meters by 14 and is shaped like a diamond. Its layers, as thin as a strand of hair, were folded like an accordion and will now stretch until they are tens of inches apart.
They are made of kapton, a material chosen for its resistance to extreme temperatures because the face closest to the sun can reach 125°C and the farthest face -235°C.
Its opening was made possible thanks to hundreds of pulleys and cables to guide them, as well as motors to extend each spark plug from each tip of the diamond.
ready in a few months
On Monday, the first three layers were successfully opened and stretched. On Tuesday morning, the teams did the same with the last two.
Before that, the two “palette structures” that contained the sun shield were activated.
This heat shield is essential because James Webb’s scientific instruments only work at very low temperatures and in the dark.
The big news about this telescope is that it will operate through the near and medium infrared spectrum, wavelengths visible to the naked eye.
In order to detect the weak light, coming from the ends of the universe, it cannot be affected by solar radiation, but neither by that emitted from the Earth and Moon.
The next step is to open the mirrors: first a secondary, smaller and placed at the end of a tripod, and then the main one, covered with gold and measuring 6.6 meters in diameter.
Once set up, the James Webb will arrive at its destination, known as the Lagrange 2 point. It will then need to cool and calibrate the instruments and adjust the mirrors very precisely.
Six months after launch, the telescope will be ready to trace back to the origins of the universe and search for habitable environments outside our solar system.
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