The Hubble Telescope’s Wide Field Camera 3 malfunctioned a few weeks ago when it independently detected unexpected voltage levels, at which point engineers started analyzing internal data from the instrument to try to solve the problem. Fixing this issue, of course, would be very important as this instrument is the orbiting telescope’s most-used instrument; fortunately, they found that innocuous telemetry data caused the problem, not a bigger hardware failure.
In a statement, NASA explains, “Upon further investigation, the voltage levels appeared to be within range, yet the engineering data within the telemetry circuits for those voltage levels were not accurate. In addition, all other telemetry within those circuits also contained erroneous values indicating that this was a telemetry issue and not a power supply issue.”
NASA also comments that engineers simply uplinked commands to the telescope to reset Hubble’s WFC3 instrument telemetry circuits. With this simple operation, they were able to reset all voltage values to normal and the camera came back online. Officials are now planning to further investigate why the voltage data values had proved erroneous.
On board the Hubble Telescope, no other instruments appear to have been effected by this issue. These instruments include another imager, the Advanced Camera Surveys, as well as the Cosmic Origins Spectrograph, and the Space Telescope Imaging Spectrograph.
You may recall that NASA halted Hubble Telescope scientific observations back in October for three weeks because one of the onboard gyroscopes failed. These gyroscopes are important, of course, because they control the ability to point the telescope. When this gyroscope failed, only three of the six total gyroscopes were in operation, which caused a little confusion at first but controllers managed to resume observations later in the month by simply using the three remaining gyroscopes.
Restoring functionality to the Hubble Telescope is very important as it is still in the middle of its mission. NASA says they do not want to have to end operation until they are able to successfully launch the James Webb Space Telescope, whose launch continues to encounter delays with its newest liftoff date set for 2021. NASA hopes, however, that Hubble will remain in use until at least 2025.