Its payload computer first experienced a problem back on 13 June, and the instruments were then placed in a safe configuration and science operations suspended. Since July 15, the spacecraft has been switched to backup hardware.
Nasa describes the success of the switch as follows:
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.
Most observations missed while science operations were suspended will be rescheduled for a later date, says Nasa.
Hubble Space Telescope
Hubble was launched on 25 April 1990 and in its 31 years of operation it has taken over 1.5 million observations of the universe. Over 18,000 scientific papers have been published using its data.
“Hubble is an icon, giving us incredible insight into the cosmos over the past three decades,” said NASA Administrator Bill Nelson.
“I’m proud of the Hubble team, from current members to Hubble alumni who stepped in to lend their support and expertise. Thanks to their dedication and thoughtful work, Hubble will continue to build on its 31-year legacy, broadening our horizons with its view of the universe.”
Avoiding distortions of the atmosphere, Hubble can view planets, stars and galaxies, some more than 13.4 billion light years away.