If the team can't bring the malfunctioning gyroscopes back, it'll switch to operating with one or two gyroscopes, Osten said. NASA's decision to retire its space shuttles in 2011 means that astronauts can not service the 28-year-old observatory as they once did.
The Hubble space telescope, which has been in orbit since 1990, is now out of action because of a gyroscope failure, the U.S. space agency said Monday. Instead, the team opted to "put the observatory into a safe-point mode that it could stay in for ages if it needs to while an investigation occurs".
In the wake of the fifth and final space shuttle servicing mission in 2009, two of the older-generation gyros failed, one at a time, leaving Hubble with just four operational units. "The remaining three gyros available for use are technically enhanced and therefore expected to have significantly longer operational lives", NASA wrote. Exhibiting end-of-life behavior for about a year, the gadget actually exceeded expectations.
The Hubble Space Telescope is now operating in safe mode, with all science operations suspended, after one of the three gyroscopes used to aim the telescope failed on Friday 5 October.
Failing gyroscopes are not uncommon, so Hubble was equipped with six new ones (which included backups in case of failure) on a 2009 mission to service the telescope, which was launched all the way back in 1990.
"The plan has always been to drop to 1-gryo mode when two remain", Osten said in a Twitter exchange.
Update for 12:50 p.m. PT Oct. 8: We've added NASA's statement on the gyro issue. "[We] nearly pulled the plug on it back in the spring".
Even if that particular gyroscope stays out of order, Hubble can get back to work - while it works best with three gyroscopes, the telescope can run on just one without losing too much scientific power. It has no overall impact on the scientific capabilities of the decades-old space telescope but would mean limited sky coverage for scientists.
The instrument, named after astronomer Edwin Powell Hubble, has been celebrated for its involvement in tracking asteroids, analysing the Kuiper Belt and documenting the nebula of dying stars.