Hubble is equipped with six gyroscopes to orient the telescope.
In a statement October 8, NASA said the spacecraft went into a protective safe mode around 5 p.m.
"Hubble entered safe mode after one of the 3 gyroscopes actively being used to point and steady the telescope failed", NASA said in a statement.More news: China, US Exchange Sharp Words During Pompeo Visit
If the team can't bring the malfunctioning gyroscopes back, it'll switch to operating with one or two gyroscopes, Osten said. Thus, each problem brings the telescope, one of the most famous and productive observatories in the history of astronomy, one step closer to its eventual end. Experts at NASA's Goddard Space Flight Center and the Space Telescope Science Institute are analyzing the situation and conducting tests to find out whether the third gyro can be recovered. The current problem, though, is a reminder that, with the retirement of the shuttle, NASA now lacks a means to fix or upgrade Hubble.
It's impossible to overstate the amount of data Hubble has collected during its 28-year stint in space, and its overall contributions to science. The gyro lasted about six months longer than we thought it would (almost 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. "Which the Astro community wants desperately", Osten tweeted. "Very stressful weekend. Right now [the Hubble Space Telescope] is in safe mode while we figure out what to do".
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.
Hubble's primary mirror is 2.4 meters (7 feet, 10.5 inches) across and in total is 13.3 meters (43.5 feet) long - the length of a large school bus.