The Hubble Space Telescope has resumed science operations in single-gyro mode after one of its three remaining gyros was declared suspect.on Friday, June 15, 2024, albeit with what the Hubble team described as"minor limitations." Engineers plan to monitor the suspect gyro in the hope that it stabilizes and can be used again., there is a 12 percent decrease in efficiency in operations during one-gyro mode due to the extra time that's needed to lock onto a science target.
In addition to the extra time needed to get the telescope pointing in the correct direction, the mode also reduces the area of sky that the Hubble can point to, so transient events or targets of opportunity – an exploding star or an impact on Jupiter – might be missed. Any moving objects closer to Earth than the orbit of Mars might also be missed – Hubble needs three gyros to move fast enough to track them.
All told, NASA reckons that the total decrease in productivity will be"roughly 20 to 25 percent" from when three gyros were in use. AStill, three-quarters productivity is far better than nothing at all, and the Hubble has been a highly productive observatory during the 34 years since its launch.The Space Shuttle was used to service the observatory, and the final servicing mission – STS-125 – replaced all six gyros.
The Space Shuttles have long been retired, and there is currently no commercial servicing mission on the books for the veteran observatory. Still, it is at least back in operation now, even if scientists might need to rethink some planned observations. The US space agency said:"NASA anticipates Hubble will continue making discoveries throughout this decade and possibly into the next, working with other observatories, such as the agency’s James Webb Space Telescope for the benefit of humanity." ®Remember when the Hubble Space Telescope was more punchline than science powerhouse?