The Hubble Space Telescope has been turned off for the third time in a month after it gave false readings.
Nasa put the space observatory into safe mode, which is when all non-essential systems of a satellite are turned off to prevent any further malfunctions, on November 19, 21 and 23.
Hubble has been operating since 1990 and has made numerous discoveries, including other galaxies, two moons that orbit Pluto and nebulas – clouds of gas or dust.
“Nasa is working to resume science operations of the agency’s Hubble Space Telescope after it entered safe mode on November 23 due to an ongoing gyroscope (gyro) issue,” the US space agency said.
“Hubble’s instruments are stable, and the telescope is in good health.
“The telescope automatically entered safe mode when one of its three gyroscopes gave faulty readings.”
The gyroscope measures the telescope's orientation. It is part of the same system that helps to record the turn rate.
Nasa said Hubble's operations are suspended while in safe mode.
“The team is now running tests to characterise the issue and develop solutions,” the US space agency said.
“If necessary, the spacecraft can be reconfigured to operate with only one gyro.”
The spacecraft had six new gyros installed during the fifth and final space shuttle servicing mission in 2009.
To date, three of those gyros remain operational, including the gyro currently experiencing fluctuations.
“Hubble uses three gyros to maximise efficiency, but could continue to make science observations with only one gyro if required,” said Nasa.
It was estimated that Hubble's lifespan would last only 15 years when it launched, but it exceeded expectations as it continues to make landmark discoveries.
A more advanced observatory – the James Webb Space Telescope – was launched in 2021 by Nasa, the European Space Agency and the Canadian Space Agency.
It is 100 times more powerful than Hubble and can see much further into space to spot galaxies and stars that were formed shortly after the Big Bang.
The $10 billion “time machine” has already made stunning discoveries, including some of the oldest galaxies ever found and features of astronomical events that could help scientists better understand the universe.