Observations with the telescope are scheduled to resume in mid-June, although at a slower pace.
The Hubble Space Telescope on Earth, taken in 2009 after its servicing mission. Credit: NASA
After repeated outages due to a wavering gyroscope, the Hubble Space Telescope will switch to operation using a single gyroscope, NASA announced June 4. The telescope's array of gyroscopes helps measure and control the attitude or orientation of the telescope and keeps Hubble stable and its images sharp.
The most recent pause in Hubble's scientific observations came after one of its gyroscopes sent faulty readings, causing the observatory to enter safe mode May 24. While the telescope should ideally use three gyroscopes to efficiently monitor and control its movement in all directions, it can remain operational with a single gyroscope.
Hubble now has two healthy gyroscopes left, out of six that were installed during its most recent servicing mission in 2009. Resuming operations with a single gyroscope protects the other for later use.
Contingency plans
Using a gyroscope was always part of NASA's contingency plan for Hubble. The technique uses other onboard sensors, such as cameras and magnetometers, as substitutes for failed gyroscopes, and was developed more than two decades ago to keep the observatory operational as long as possible.
Hubble has operated with only two gyroscopes before. From 2005 to 2009, before its final Space Shuttle servicing mission, it used only two gyroscopes, and in 2008, NASA tested single-gyroscope mode. This test found no impact on the quality of the scientific data collected by Hubble.
Trading with a gyroscope comes at a cost. Hubble will be slower to orient itself, take longer to find targets, and won't be able to change where it looks as frequently as before. The telescope will also be unable to track objects closer to Mars' orbit, as they will move too quickly through its field of view.
NASA officials aim for Hubble to resume operations in its new configuration in mid-June.
