NASA has successfully restored Hubble’s full operation. All four active instruments are now online collecting science observations.

In late October, Hubble was down again for the second consecutive time in 2021. Scientists discovered that Hubble lost data synchronization messages. They took the telescope offline to investigate. The team focused its efforts on the hardware that commands the instruments. In particular, the Circuitry of the Control Unit that generates the synchronization messages and transmits them to the instruments.

In November, the team was able revive Hubble’s most used camera Wide Field Camera 3. It was responsible for more than a third the spacecraft’s observation time. The successful revival of this camera made it possible to complete the telescope’s recovery.

NASA today announced that all four instruments were fully activated on December 6. The team has not experienced any synchronization messages issues since November 1st.

NASA states that they will continue to develop and test Hubble’s software changes that will allow them continue operations even if there are lost synchronization messages. In mid-December, the first of these updates is expected to be applied to the Cosmic Origins Spectrumtrograph. In the coming months, similar updates will be made to all other instruments.

Because it is not possible to directly work on Hubble, Hubble can be difficult to maintain. NASA engineers can now only repair and troubleshoot the telescope remotely using remote software fixes, instead of the shuttles that used fly to it periodically.

Hubble was in continuous operation for 31 years prior to the 2021 hiccups. Hubble was almost offline for a month in June due to a glitch with its payload computer. This could have caused the telescope to go down permanently. The second issue was only for a little over a month but was quickly resolved remotely. Hubble will continue to observe the cosmos, but for now it is back at work. Hubble’s successor is the James Webb Space Telescope and will be launched no sooner than that.