Last week, the Hubble Space Telescope shut down in orbit after a mechanical fault in one of its gyroscopes (gyros) forced the spacecraft to enter safe mode.
As the Inquisitr previously reported, the space telescope is fitted with six gyros but only actively uses three of them. Their role is to help the spacecraft reorient itself and lock onto its observational targets as it examines the sky.
The oldest of the four “Great Observatories,” Hubble was launched in 1990 and received new gyros in 2009 — installed by astronauts in space during the telescope’s final servicing mission. Three of these gyros are now out of commission, with the last one failing on October 5.
“The gyro that failed had been exhibiting end-of-life behavior for approximately a year, and its failure was not unexpected,” NASA officials stated on October 8.
Over the past week, the space agency has been hard at work trying to fix the problem, so that Hubble can get back to doing what it does best — studying the sky to unravel the mysteries of the cosmos.
As a first measure to get Hubble back on its feet, so to speak, NASA powered a backup gyro that had been held in reserve. But the plan hit another snag when the backup gyro didn’t perform “at the level required for operations.”
So, NASA convened an anomaly review board — an expert panel to study the problem and figure out what needs to be done next.
“We’re continuing to work toward resuming science operations of Hubble,” NASA tweeted on October 12, when the space agency issued an update on the fate of the telescope.
We're continuing to work toward resuming science operations of @NASAHubble after the telescope entered safe mode due to a failed gyroscope a week ago. An anomaly review board was formed to identify the cause of this behavior and determine solutions. More: https://t.co/WPwCGVuChJ pic.twitter.com/Rgipuox2TJ
— NASA (@NASA) October 12, 2018
According to the update, the gyro that was recently tuned on is technically enhanced, just like the other two that Hubble is currently using. This means that, unlike the gyro than failed this week, these three are expected to last longer.
However, the trouble with the backup gyro is that, although it “is properly tracking Hubble’s movement,” it’s reporting abnormally high rotation rates.
“This is similar to a speedometer on your car continuously showing that your speed is 100 miles per hour faster than it actually is; it properly shows when your car speeds up or slows down, and by how much, but the actual speed is inaccurate,” NASA explained.
This becomes a problem whenever the telescope locks onto specific targets, because this is when the gyro needs to do precision work and accurately measure very small movements, notes Space News.
“The extremely high rates currently being reported exceed the upper limit of the gyro in this low mode, preventing the gyro from reporting the spacecraft’s small movements,” said NASA officials.
If the anomaly review panel is able to correct the problem, Hubble will resume operations and go back to using three gyros. In case the malfunctioning gyro can’t be fixed, the space telescope will switch to an already defined and tested “reduced-gyro” mode and go on functioning with only one gyro.
While this means less sky coverage for Hubble, the measure “will still provide excellent science well into the 2020s, enabling it to work alongside the James Webb Space Telescope and continue groundbreaking science,” clarified NASA.
Meanwhile, the youngest of the “Great Telescopes” — NASA’s Chandra X-Ray Observatory — is also in trouble and has joined Hubble in safe mode on October 10, the Inquisitr reported yesterday. According to the space agency, Chandra seems to be experiencing a gyroscope problem as well.
“The scientific instruments are safe & there is an investigation underway looking at the cause of the safe mode transition,” NASA tweeted on October 12.
On Wednesday, the @ChandraXRay Observatory entered into safe mode. The scientific instruments are safe & there is an investigation underway looking at the cause of the safe mode transition. Designed for a 5-year mission, Chandra is now 19 years old. Info: https://t.co/AShwpDI03w pic.twitter.com/6FpX5xyk31
— NASA (@NASA) October 12, 2018