via BBC

One of the most complex challenges in space exploration is maintaining display objects that are kept off our planet. In 1990, what is probably the most iconic telescope ever made was launched into the orbit of our planet and it has given us the possibility of looking closely at the stars in ways we could never have imagined.

This device is, of course, not a common telescope. It is a very complex computer that only experts can fully handle and understand. Its maintenance is just as complicated.

On June 13, 2021, the Hubble Telescope’s computer had some problems and suddenly stopped for the first time in so many years suspending science observations. This immediately caused alarm in the scientific community and NASA quickly began an investigation to detect the causes and find possible solutions.

“After analyzing the data, the Hubble operations team is investigating whether a degrading memory module led to the computer halt,” NASA said in a statement on June 16, 3 days after the incident.

The purpose of the payload computer is to control and coordinate the science instruments on board the spacecraft, so when the problem was detected, the main computer stopped receiving the “keep-alive” signal that means everything is fine.

At NASA’s Goddard Space Flight Center in Greenbelt, Maryland the authorities decided to restart the machine but it kept sending them the same error so they decided to place all the science instruments in a safe mode configuration.

The last servicing mission to the Hubble Telescope was in 2009 so an error like this was not expected for a few more years.

After several intense days of research, diagnostics, and testing on July 16, NASA successfully switched to backup hardware on the Hubble Space Telescope, including powering on the backup payload compute. The following day all the operations of the science instruments began again and by July 19 the first images taken by the telescope were received.