The Hubble Space Telescope has a crashed payload computer, which NASA says is likely related to a degraded memory module. As a result, scientific research is temporarily not possible. This computer is from the 1980s.
NASA reports that the computer has stopped working since Sunday. Based on analyzing the data, the Hubble team is investigating whether a malfunctioning memory module is the direct cause. The team is in the process of switching to one of the existing backup modules. That should be completed on Wednesday, after which it should become clear on Thursday whether the problem has been definitively solved. Only then can all scientific instruments be switched on again.
The job of this computer is to manage and control all scientific instruments. On Sunday, this computer no longer received the ‘keep-alive’ signal; this is a standard handshake between the payload computer and the main computers of the telescope to indicate that everything is OK. When that signal failed to materialize, all scientific instruments were automatically placed in a safe mode. NASA’s Goddard Space Flight Center rebooted the computer Monday, but the same problem soon reappeared.
NASA tells The Register that the payload computer has a total of four memory modules and only one is needed. A spokesperson says it can be compared to a board with memory chips on a laptop that can be exchanged in case of a problem. The supposed solution, swapping the memory module that probably has a problem, has been done several times during hardware testing prior to launch.
This is a computer from the 1980s: a NASA Standard Spacecraft Computer-1, or NSSC-1. This computer is part of the Science Instrument Command and Data Handling module, which was replaced by astronauts in 2009 during the last maintenance mission. According to NASA, this module has several levels of redundancy that can be switched over so that the module can serve as the primary system when needed.
The Hubble Space Telescope has been orbiting Earth for more than 30 years now. The telescope was launched on April 24, 1990. Then there were immediately problems, in the form of a deviation in the primary mirror. As a result, Hubble was initially unable to take sharp photos. This was later resolved. More recent are, for example, a broken visible spectrum camera in 2019 and earlier this year there was one software problem which meant that the telescope was unable to conduct scientific observations for a short period of time.