Science

Hubble Space Telescope Enters Safe Mode After Gyroscope Failure

Hubble Space Telescope Gyroscope Failure
Image Credit: NASA

NASA’s Hubble Space Telescope has entered safe mode following a gyroscope failure, according to the space agency. Hubble uses its gyroscopes to keep itself aimed precisely at what astronomers are using it to observe. With safe mode on, observations are halted until NASA’s engineers figure out what’s wrong with the gyroscope. Right now, the solar-powered telescope is pointed at the Perseus Cluster.

Although NASA revealed the telescope’s gyroscope failure, it didn’t disclose very many other details. The space agency will announce when the issue has either been fixed or determined to be unfixable. For now, NASA hasn’t offered any timeframe on when can we expect Hubble Space Telescope to come back into operation. Engineers who work on Hubble say they are addressing the problem. A NASA spokesperson posted this update on Hubble’s Twitter account:

The failed gyroscope has already been showing end-of-life behavior for about a year, NASA said on its website. Two of Hubble’s other gyros of the same type have already failed. A NASA spokesperson offered this additional clarification on Twitter:

The Hubble Space Telescope sports six high-speed gyroscopes which help it accurately aim and move from target to target while keeping it in a fixed position. The telescope only needs three gyros for it to work properly, while the other three are held in reserve in case of failure. There are three gyros of the older generation with a history of showing signs of malfunction after 50,000 hours of service. The other three are of a newer generation and are less likely to show such signs until several hundred thousand hours.

During the fifth space shuttle servicing mission that took place in 2009, two of the older-generation gyros stopped working, leaving Hubble with only four operational gyros, according to CBS News. Until this past Friday, Hubble worked properly with two newer gyros and one of the older-generation gyros, while the third newer unit was held in reserve.

“Three of them were on and one was off,” Ken Sembach, director of the Space Telescope Science Institute at Johns Hopkins University, told CBS News. “One of the (older-design models) that was on has been acting kind of flaky for a year, and we’ve expected it to reach its end of life. And, in fact, that actually happened on Friday night. It finally gave up the ghost and failed. Everybody said OK, no big surprise, we’ve been expecting that for a year, let’s turn on the gyro that was off at the time to get back onto science operations.”

However, when they turned out the gyro that had been held in reserve, they found that it wasn’t working satisfactorily. As a result, NASA put Hubble into a safe-point mode.

Even though NASA engineers are working on a fix, the Hubble Space Telescope can still operate with just one gyroscope, if problems with the gyros continued. However, Sembach noted that pointing at targets will be more difficult in this case, making it rely more on its star trackers and magnetometers.

Observations using the Hubble Space Telescope are temporarily suspended until NASA engineers see what they are going to do about the gyroscope failure , although the failure highlights that there is not much time left for the telescope. The James Webb Space Telescope should be Hubble’s successor in the future, although it’s still not expected to launch until 2021.