The Hubble Space Telescope is in an uncomfortable predicament. NASA's 28-year-old eye on the cosmos is in safe mode after the failure of a gyroscope used to help aim the telescope at its imaging targets.
Hubble team announced the problem on Twitter Monday, writing, "Mission experts are taking steps to return Hubble to great science. More updates will follow."
Hubble is equipped with six gyroscopes, but it's been operating with only three active gyros. "At any given time, Hubble needs three of its six gyroscopes operating to ensure optimal efficiency," NASA says. Friday's failure means Hubble is down to just two, a situation that triggered its entry into safe mode.
Rachel Osten, deputy mission head for Hubble with the Space Telescope Science Institute, has dropped a few more details about the problem on Twitter. "First step is try to bring back the last gyro, which had been off, and is being problematic," she wrote on Sunday.
Osten said the team knew the gyroscope issue was imminent, but she sounds confident about overcoming this latest obstacle to Hubble's continuing operation. "We'll work through the issues and be back," she wrote.
Hubble could potentially function with just two or even a single active gyroscope, so the latest failure shouldn't be the end of the road for the telescope. Osten described the current situation as "not really scary."
Astronauts on a space shuttle servicing mission in 2009 replaced all six of Hubble's gyroscopes, but NASA no longer has the option of sending a shuttle for repairs. The shuttle program shut down in 2011.