NASA JWST (acronym of James Webb Space Telescope) is one of the most awaited short-term projects by many astronomy and, of course, from scientists around the world. It is a large space telescope that will have to take the place of Hubble , although actually the two typologies cannot be properly superimposed.
Very beautiful (aesthetically) but also very complex to achieve and not with a few technological-political difficulties that led to more than one referral . But in these days NASA JWST has taken a fundamental step forward, a real “milestone” as defined by the US space agency.
NASA JWST was assembled completely for the first time in California. In fact the space telescope is composed of two large units: the upper part of the mirrors (gold) and the instruments with and the lower part which instead acts as a large damping system for the radiations coming from the Sun.
We recall that NASA JWST “will work” observing in the infrared spectrum and the Sun and other bodies (such as the Earth or the Moon) are a significant source of disturbance. Furthermore, the telescope James Webb will have to scan the Cosmos in search of exoplanets and moons and will therefore need a lot of precision to have reliable results
Obviously the long journey that will bring NASA JWST into the Space will include other steps: the next will be the electrical connection of the two halves and then move on to checks on the operations performed.
The part of the shield that includes five layers and the cooling system of mirrors and scientific instruments will be completed. Accuracy will be fundamental (even more than in other types of telescopes) because NASA JWST will be positioned very far from the Earth. As an example, the ISS is located at about 400 km of altitude, Hubble a 570 km, the Moon at 384 thousand km while the James Webb will be at 1.5 million km (second Lagrange point or L2).
If something unexpected happens as in the first part of Hubble's life the corrections (which in that case were made by astronauts using the Space Shuttle) would not be possible. And given the cost of this mission, to fail is even less contemplated than in other cases.
Now the launch of NASA JWST is scheduled for 2021 while in the remaining period there will still be more operations to be completed to ensure that everything is in place. A small step for a telescope, a great step for humanity.