NASA has successfully fixed the Hubble Telescope’s payload computer, after it malfunctioned and stopped working over a month ago.

After a month of trying to get Hubble up-and-running again, NASA was able to narrow the problem down to the Power Control Unit (PCU), responsible for maintaining the proper electrical voltage. Engineers began the process of switching to the backup PCU yesterday, and the operation was successful.

The switch included bringing online the backup Power Control Unit (PCU) and the backup Command Unit/Science Data Formatter (CU/SDF) on the other side of the Science Instrument and Command & Data Handling (SI C&DH) unit. The PCU distributes power to the SI C&DH components, and the CU/SDF sends and formats commands and data. In addition, other pieces of hardware onboard Hubble were switched to their alternate interfaces to connect to this backup side of the SI C&DH. Once these steps were completed, the backup payload computer on this same unit was turned on and loaded with flight software and brought up to normal operations mode. 

NASA says it will still take a day or more to bring the scientific equipment out of safe mode, and engineers are continuing to monitor the hardware to make sure everything continues operating properly. If everything goes well, it appears Hubble will be back in action, delivering more breathtaking photos of the cosmos.