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One sensor on the James Webb Space Telescope is temporarily out of commission, but project managers are hopeful it will not be a long-term issue. NASA said on September 20 that it had discontinued the use of one of four observations during preparations for observation, a mechanism supporting one of the Mid-Infrared Instruments (MIRI) on JWST "seems to have increased friction." Controllers first identified the problem on August 24, and the project formed an anomaly team to investigate it on September 6.
The issue impacts telescope-based medium-resolution spectroscopic investigations. The three other MIRI observing modes of imaging, low-resolution spectroscopy, and coronagraphs are unaffected and continue to be used for observations. The problem was downplayed by NASA representatives in presentations at the International Astronautical Congress (IAC) on September 21. Thomas Zurbuchen, NASA's associate administrator for science, said during a plenary address, "We're taking a break and just making sure it works well." Eric Smith, the JWST program scientist at NASA Headquarters, said during a news conference later in the day that engineers "do not believe that this will preclude utilizing this instrument; they wanted to know why they were witnessing this particular increase in friction." He noted that the decision to discontinue use was made with "extreme prudence." the medium-resolution spectroscopic mode.
One of the three difficulties for JWST operations that Zurbuchen identified in his IAC presentation is the MIRI problem. The other two are communications during the planned Artemis 1 mission via the Deep Space Network (DSN) and micrometeoroid impacts on the telescope's mirrors. However, one of the strikes, which occurred during the spacecraft commissioning phase, was greater than anticipated, according to Smith. The project is experiencing the predicted amount of micrometeoroid hits on the mirror. We anticipate maybe one hit that size each year, he said. We'll have to confirm that over the year, but so far, it seems like we saw that impact early.
Following the briefing, he noted that the requirements placed on the Artemis 1 mission would shorten the DSN's window of opportunity for communicating with JWST. We have eight hours of contact each day under nominal operations, the man said. When the daily total falls below four hours, we become concerned. During the mission, there might be a "handful" of days where DSN time is less than four hours, he said. The spacecraft will then be able to fly longer between DSN interactions since the controllers will have planned observations that require fewer data storage. Science is unaffected by the moving of things, despite this.
Otherwise, JWST continues to outperform expectations. The expedition unveiled an infrared photograph of Neptune, its rings, and moons at the IAC press conference, the most precise view of the distant planet since the Voyager 2 probe sailed by it in 1989. In the far reaches of the universe, the telescope has also detected galaxies, some of which are only 400 million years old. Guido Roberts-Borsani, a postdoc at UCLA participating in those observations, noted during the press briefing that the James Webb space telescope has been sending data to us for a little over two months and that it has already changed the study of extremely early and far-off galaxies. Take a look at what we can accomplish in a year.
Yash Ranjan09/23/2022
