In a recent blog post I wrote about wrote about the James Webb Space Telescope’s success so far in being able to provide images of the universe back to Earth since it’s extraordinary launch exactly three months ago. As of this morning the JWST has officially entered the second month of its six-month-long commissioning period, this is encouraging news since the telescope has so far completed among the riskiest steps of its deployment.
Still, since the successful deployment of the telescope’s sunshield the telescope’s operators at the Space Telescope Science Institute in Baltimore, Maryland, have been working very tediously to align the JWST’s primary mirror. This process begins by defocusing the segment images by moving the secondary mirrors slightly. Mathematical analysis, called Phase Retrieval, is then applied to the defocused images to determine the precise positioning errors of the segments. Adjustments of the segments then result in 18 well-corrected “telescopes.” However, the segments still don’t work together as a single mirror. After an image array is obtained, it can then be used to perform segment alignment, which is able to correct most of the large positioning errors that occur with each mirror segment.
This all is good news and the mission is going just about as good as it can. Although, one further…
