Both orbiting observatories are old: Hubble is 28, while Chandra is 19. Flight controllers are working to resume operations with both.
NASA says it’s coincidental both went ‘asleep’ within a week of one another.
An astronomer who works on Chandra, Jonathan McDowell of the Harvard-Smithsonian Center for Astrophysics, tweeted Friday that ‘Chandra decided that if Hubble could have a little vacation, it wanted one, too.’
Source: ANOTHER space telescope has switched itself into ‘safe mode’: NASA reveals Chandra X-ray Observatory has shut down just a week after Hubble suffered the same fate – but says the timing is ‘coincidental’