The Webb Space Telescope’s optics passed an important test

Image: This test image from the Webb Space Telescope, taken on March 16, 2022, shows the distant star 2000 light-years away 2MASS J17554042 + 6551277, surrounded by other stars and distant galaxies. (NASA/STScI)

On March 11, the precise optical tuning of the primary mirror (“eye”) of the Webb Space Telescope was completed. Webb passed all the tests as well or even better than expected and could easily capture light from distant galaxies and transmit it to his scientific instruments. As proof of this, NASA has provided a test image showing the star 2MASS J17554042 + 6551277, against large numbers of galaxies in the background.

Although it is still months before Webb is fully operational, this feat shows that the new space telescope’s primary optical system is working properly. Its main camera – the near-infrared camera – aligns perfectly with the telescope’s mirror.

summer

Over the next six weeks, Webb’s team will complete the remaining alignment steps and final preparations to operate the space telescope’s science instruments: two more infrared cameras and two spectrographs. A computer algorithm evaluates the performance of each instrument and calculates the final corrections needed to properly align the telescope for all instruments. Then, the remaining small deviations in the positions of the main mirror segments will be corrected.

The alignment process is expected to be completed by early May at the latest. It will then take another two months before all the tools are ready. The first full-resolution scientific images and data will be released in the summer.