The issue is not in a mirror. The problem is in a rotating diffraction grating that acts like a prism to select the wavelength of electromagnetic spectrum (all longer wavelength than visible light) that reaches the photodetectors. The grating mechanicals seem to have unexpected drag that slows down the rotation into the desired position. It could be from temperature variations (one side of satellite is very hot and the other side is very cold) or it could be a micro meteroite strike that damaged bearing surfaces. It could be from a speck of dust that shook loose during launch.
You can bet that they are working on a triage strategy to put the diffraction grating into the position that provides the greatest value (likely the longest wavelength IR setting) in the event the grating gets stuck.
Note that this is only the medium resolution sensor, so even if it completely failed there would still be other sensors that are very valuable.
Heh
Movie quote
Thanks for the observation on setting the mechanism on its best setting in case it gets stuck.
Plus all of the other sensors that are working. Not exactly “backup”, but still valuable tools.
I was watching something about Princess Diana’s wedding. They had a backup wedding dress, bridal bouquet and the main cake available in case something went wrong.
I take it the fix is all through manipulation from a computer from here?