The James Webb telescope is finishing its optical adjustments, time for the instruments!

Alignment and optical adjustments are complete, 18 JWST mirrors
behave perfectly. A success for this phase of delicate adjustments, and another step towards the start of scientific operations! The “first image” post-alignment already suggests its capabilities, revealing thousands of stars and galaxies.

The experts are unanimous, it’s very promising!

One more step for the JWST

After so many years, each additional step leading to the commissioning of the James Webb Telescope is scrutinized, commented on, put into perspective. Yes, the months are long until everything is in place to start the long-awaited scientific campaign of the largest and most capable optical telescopes ever sent into orbit. But there are a lot of steps to go through!

Still, everyone is starting to breathe, because the results are there: the optical adjustments of the telescope are finished, its 18 mirrors work as one and the performance is there! “ Now we know we built the right telescope “, explains Ritva Keski-Kuha, responsible for the optical part ” Alignment and focus have been tested on a star, and the results are already exceeding our expectations “.

Alignment: chaotic good

Published with a new selfie that effectively shows that the mirrors are aligned in a perfect “honeycomb”, the image marking the end of the optical part adjustments is remarkable. While it was centered on a star to show its performance with the 18 “unified” and adjusted mirrors, it reveals future favorite subjects of the telescope: bright stars, but also galaxies by the hundreds that we can guess despite the relatively short pause times (3 x 500 seconds).

What is especially underlined by all the teams is that there was no hitch in the settings, and that the James Webb telescope works as well as its theoretical physical limits, it is a very good omen… although you have to be careful.

Corrections and instruments in sight

Since March 11, the next step has already started, the MIMF: multi-field and multi-instrument alignment. It is no longer a question of working on the primary and secondary mirrors, but of checking and quantifying the exact position of the fields of view of the four instruments in relation to each other… Since all the adjustments have so far been carried out with NIRCam .

Tiny corrections may apply depending on the results, but it won’t take very long. And the instrument used for the fine pointing of the telescope (the FGS for Fine Guidance Sensor) has also been resolved. Although the scientific campaign will not start until the beginning of June at best, there is a very pleasant “final straight line” atmosphere floating around the project, three months after its take-off. The MIRI instrument for its part, which will be the last to enter service, will soon activate its active cooling system.

Source: NASA