NASA is one step closer to fully aligning James Webb's iconic golden mirrors

The telescope's primary mirror will soon "slowly form into its precise, intended shape".
Chris Young
An artistic illustration of the James Webb Space Telescope.Wikimedia Commons

We're almost there.

James Webb has already taken its first images of stars and its first selfie, and now, it's time to finish calibrating the powerful instruments that will power the $10 billion telescope mission, a blog post from NASA explains.

NASA confirmed that the first stage of mirror alignment is complete, meaning we are another crucial step closer to full deployment. One down, two to go.

The first stage of mirror alignment is complete

Last week, February 14, NASA revealed selfie images taken by the James Webb Space Telescope, in which it showed off its partially aligned golden mirrors from the perspective of an onboard camera. Three days prior, the telescope took its first images of space, showing a composite of one star from 18 different angles. 

Now, mission control has completed the next step in aligning the observatory's mirrors, so that they are all aligned to perfectly focus on that one star. When that happens, James Webb will be fully operational, meaning it will be free to start taking images that will provide new insight into the early universe, potentially habitable exoplanets, and possibly even alien life. 

As NASA explains in its post, engineers completed the first stage in the alignment process, which is called "Segment Image Identification." To do so, the telescope had to capture images from each of its 18 primary mirror segments. James Webb was able to successfully take 18 images of a single star and arrange them into a planned hexagonal formation, meaning it passed its first true test.

NASA is one step closer to fully aligning James Webb's iconic golden mirrors
The 18 dot image array, captured by James Webb. Source: NASA/STScI/J. DePasquale

James Webb's first research images will be worth the wait

With that stage complete, the team has now begun the next phase, called "Segment Alignment." During this part of the process, mission control will correct large positioning errors of the mirror segments and update the alignment of the secondary mirror. This will help to make each of the 18 individual images of the same star more focused in future observations. "We steer the segment dots into this array so that they have the same relative locations as the physical mirrors," Matthew Lallo, systems scientist and Telescopes Branch manager at the Space Telescope Science Institute, said in NASA's post. "We can now actually watch the primary mirror slowly form into its precise, intended shape!"

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The third phase, called "global alignment", will bring the 18-star image on top of each other, meaning the golden mirrors will be correctly trained on a single point. Once that stage is complete, the immense observational power of James Webb will be unleashed, providing a window with never-before-seen detail into the earliest days of our universe. NASA has explained that those first impressive images — taken for research purposes, and not for calibration — will likely come sometime in late June or early July. 

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