Before it can study the first stars and galaxies or characterize nearby exoplanets, the James Webb Telescope will first have to survive its launch. This will be followed by a long sequence of deployment in deep space before returning to its observation post:the Lagrange L2 point.
A few weeks ago, engineering teams wrapped up the "long-duration testing" program at Northrop Grumman's facilities to ensure the observatory can withstand without problems the launch phase. The teams are now taking great care to prepare for his trip to Guyana during which he will cross the Panama Canal. NASA recently announced that its launch is now scheduled for December 18 .
The JWT is without a doubt the most advanced space telescope ever designed and built. The spacecraft's infrared gaze, much like Spitzer's before it, will be powerful enough to pierce through the densest cosmic dust clouds. Behind these veils of smoke, stellar nurseries and other embryonic protoplanets will be revealed before our eyes, to the delight of astrophysicists. This gaze will also be sensitive enough to pick up the faintest photons emitted by the first stars and galaxies to form after the big bang.
In short, the James Webb Telescope has the power to rewrite our cosmic history. Obviously, this assumes that everything goes as planned.
Assuming it takes off well on the morning of December 18, firmly installed in the fairing of its Ariane 5 rocket, the James Webb Telescope will follow an eastward trajectory, at above the Atlantic Ocean. Once it has travelled approximately 10,400 kilometers , Webb will detach from the second stage of his launcher. From then on, the most trying part of his journey has only just begun.
Before starting its work, the $10 billion observatory will have to position itself at Lagrange point 2, or L2, more than 1, 5 million kilometers from Earth . The gravitational tugs of Earth and the Sun balance there to create a perfect long-term parking spot for this type of observatory.
Just moments after parting ways with his rocket, the telescope's solar power array will begin to deploy to provide it with electricity. Naturally, the success of this operation will be essential. About twelve hours after launch, the ship's thrusters will then fire to correct its trajectory.
From day three, the JWT will then begin to deploy its visor, one of the most essential pieces of the mission. Imagine a stack of five polyimide "slips" the size of tennis courts. Its purpose will be to block sunlight from reaching the telescope's infrared sensors. To probe the depths of the universe, it must indeed operate at extremely low temperatures. To open this sun visor, about 150 triggers will need to fire correctly in three days. These operations will involve approximately 7,000 coins .
After six days of flight, the telescope's secondary mirror, placed at the end of three long arms, will then move into place. The next day, the 6.5 m primary mirror features a collection of eighteen beryllium-cut gold-plated hexagonal segments. Tiny actuators will push or pull each of these segments to align them down to the micrometer. Again, everything will have to work properly at the risk of dropping the mission.
Finally, a month after launch, the JWT should finally reach its Lagrange Point, concluding one of the most daring and risky space flights ever attempted for a observatory . "It's like an orchestra concert involving hundreds of people all playing different instruments “, points out Heidi Hammel, vice president of the Association of Universities for Research in Astronomy, to Scientific American. “All instruments must be ready and everyone must have practiced their part. And then we play the music “.
And this music must not have any false notes.
