Kourou.- The James Webb Space Telescope, a revolution in the observation of the universe that astronomers around the world have been waiting for thirty years, successfully took off this Saturday at 12:20 GMT aboard an Ariane 5 rocket, and it will be 1.5 million kilometers from Earth.
“Good Webb telescope separation, Go Webb”, announced Jean-Luc Voyer from the space base of Kurú (French Guiana). The upper part of the Ariane rocket released the telescope after 27 minutes of flight, which will now take a month to reach its observation point, about 1.5 million kilometers from Earth.
The largest telescope ever sent into space will orbit the Sun some 1.5 million kilometers from Earth with the ambitious mission of answering two fundamental questions for humanity: Where do we come from? And yes, are we alone in the universe?
Its power should allow it to scrutinize until the “cosmic dawn”, the moment when the first galaxies began to illuminate the universe after the Big Bang, 13.8 billion years ago.
It should also help understand the formation of stars and galaxies, and observe exoplanets so that astronomers discover more of them, and eventually, they can identify others like Earth in the future.
James Webb will follow in the footsteps of the Hubble telescope, which revolutionized the observation of the universe. It is thanks to him that scientists discovered the existence of a black hole in the center of all galaxies or of water vapor around exoplanets.
See the first galaxies
Conceived by NASA after the launch of Hubble in 1990 and built starting in 2003, in collaboration with the European space agencies ESA and Canadian CSA, the James Webb is distinctive in more than one respect.
The size of its mirror, 6.5 meters in diameter, gives it three times more surface area and seven times greater sensitivity, enough to detect the thermal signal of a bumblebee on the Moon.
Another difference is their mode of observation. Hubble scrutinizes space through visible light, but James Webb ventures into a wavelength that escapes the human eye: the near and mid-infrared, a radiation that naturally emits all kinds of bodies, from stars to humans or flowers.
This light will be studied by four instruments, equipped with image processors and spectrometers to better dissect it. Its development has mobilized a multitude of engineers and scientists led by American and European laboratories and industrialists.
Thanks to this, “looking at the same objects (as with Hubble), we will see new things”, explained in Paris the astronomer Pierre Ferruit, one of the scientists in charge of the telescope for ESA.
Among them are the first galaxies, objects whose receding has caused their light to shift towards the red. Or the young colonies of stars, which grow camouflaged by clouds of dust. Or even the atmosphere of exoplanets.
An essential condition for the proper functioning of the James Webb is an ambient temperature so low that it does not complicate the examination of the light.
If it orbited 600 km from Earth like Hubble, the new telescope would be unusable, heated by the Sun and its reflection on the Earth and the Moon.
For this reason, it will undertake a trip to 1.5 million kilometers from our planet, protected from solar radiation by a thermal shield that will dissipate heat and reduce the temperature (which is 80º C) to -233º C.
A difficult deployment
But before getting there, the machine must be deployed without failure, with a series of operations involving, for example, 140 opening mechanisms, 400 pulleys and almost 400 meters of cables just for the protective shield.
And the fact is that the telescope, with 12 meters high and a parasol the size of a tennis court, had to be folded to be placed on the Ariane 5 spacecraft.
The encapsulation was done laser-guided to avoid any damage to the instrument, which cost almost 10 billion dollars to develop.
During these maneuvers, NASA imposed draconian cleaning measures to avoid any contamination of the telescope mirror, by particles or simply the breath of an operator.
In addition, Ariane’s dust jacket was fitted with a bespoke depressurization system to prevent a pressure change from damaging the telescope as it separated from the shuttle, at an altitude of 120 km.
“For an exceptional customer, exceptional measures,” an ESA official in Kourou said on Thursday.
After 27 minutes of the launch, it will be known if the propulsion phase of the flight developed correctly, which will further strengthen the cooperation between NASA and its European partners.
In space, “strong cooperation is essential to achieve great things,” said officials from both agencies in Kourou.
It will take weeks to see if the telescope is ready to go. And it won’t be until June that your exploration of the outer reaches of space begins.