The Hubble Space Telescope is in "safe mode," which does little to explain the trouble it's in. The renowned telescope entered safe mode around 6pm Friday—meaning it's essentially now just holding steady—following the failure of one of the gyroscopes used to point and steady the instrument. The gyro had looked to be on its final legs for a year, and its failure wasn't a stunner, per a NASA release. But the surprise came when a backup gyro didn't work as planned when fired up, the result being that Hubble is now pointed the wrong way, reports CNN. Scientists are working to revive the backup, but NASA says the telescope can still function if they can't.
The Hubble started with six gyroscopes, but two failed years ago. The most recent pair of failures means that just two are currently functioning. If that remains the case, one will be shut off to serve as a backup, and Hubble will operate with a single gyro. It's not ideal, but it's workable. "While reduced-gyro mode offers less sky coverage at any particular time, there is relatively limited impact on the overall scientific capabilities," says NASA's release. No other maintenance mission is planned for Hubble, stationed 340 miles above Earth; the James Webb Space Telescope was expected to have replaced Hubble by now. But following a series of delays, it's now expected to launch in 2021, reports per Engadget. (Read more space stories.)