The gyroscopes have a habit of burning out, hence their replacement many years back, but this most recent failure means that the telescope only has two functioning gyroscopes remaining.
One newspaper quoted Rachel Osten, Hubble's deputy mission head at the Space Telescope Science Institute in Baltimore, said: "It's true".
Gyroscopes are needed to keep the 340-mile-high (540-kilometer-high) Hubble pointed in the right direction during observations.
"*IF* the third doesn't spin back up, I wouldn't be surprised if they drop to 1 gyro mode, keeping the second as reserve".
The gyro that failed is one of three in service keeping the telescope aimed and steady, NASA said, and it had been "exhibiting end-of-life behavior for approximately a year" so "its failure was not unexpected".
Although Hubble uses three gyros at a time for maximum efficiency, it can still continue to make scientific observations with just one, NASA said.
IN SPACE - MAY 13: In this handout from NASA, the Hubble Space Telescope is grappled to Space Shuttle Atlantis STS-125 by the shuttle's Canadian-built remote manipulator system May 13, 2009 in Space.
Redundancy is NASA's best friend, and so it is with the Hubble Space Telescope as NASA stands ready for failures with backups, and even in some cases, improved backup equipment. That gyro, which had been powered down, is not "performing at the level required for operations", according to spacecraft telemetry after it was commanded to turn on. Although science operations are expected to resume fairly soon, the current issues raise concerns about the future of the invaluable scientific instrument. For now, NASA hasn't offered any timeframe on when can we expect Hubble Space Telescope to come back into operation.
The Hubble telescope was launched on April 24, 1990, via the space shuttle Discovery from Kennedy Space Centre in Florida. Assuming the team can rescue the malfunctioning gyroscope, Hubble will resume operations in its standard three-gyro configuration.