NASA’s Hubble Space Telescope To Operate With One Gyroscope, Ensuring Continued Cosmic Discoveries

NASA reported that the Hubble Space Telescope would change its mode of operation to use only one gyroscope.

Problems With the Gyroscope and the Plan for Transition

This choice was made public on June 4, after one of the telescope's three remaining gyros stopped working on May 24. The change is meant to extend Hubble's mission well into the 2030s, even though it will bring new problems.

When first launched in 1990, the Hubble Space Telescope had six gyroscopes that controlled its orientation and ensured it was pointed correctly. Only three of these are left to work; one has been acting up lately.

This problem called "saturation," problem causes the gyro to show maximum slew rates even when there isn't any movement. This causes the device to enter safe mode repeatedly, which breaks down measurements.

To fix this, NASA will switch Hubble to a mode with only one gyroscope. This is part of a plan made over twenty years ago to make the telescope last longer.

In 2008, this mode was tried briefly and showed that Hubble could still send high-quality scientific data with little effect on the quality of observations. The spacecraft and base systems will need to be rearranged to work in this new way, and the change should be finished by the middle of June.

What this Means and How Scientists Can Continue to Contribute

Operating with a single gyroscope does have certain limitations. It takes longer for the telescope to readjust itself between targets, making observations about 12% less valuable.

Also, Hubble will not be able to schedule its observations as freely, especially for objects close to the Sun and moving objects closer to Mars. However, these sources only comprise a small part of Hubble's everyday observations.

Even with these problems, NASA officials are still optimistic about Hubble's future science contributions. Mark Clampin, who is in charge of NASA's astrophysics office, said this change shouldn't make it much harder for Hubble to do important scientific work. Hubble has regularly outlived its expected useful life and continues to make ground-breaking discoveries.

Future Prospects and Ongoing Efforts: Commercial Servicing Mission on Hold

Using only one gyro is part of a bigger plan to keep Hubble working and valuable. The last two gyros were upgraded models installed in the previous maintenance trip 2009.

They are meant to last much longer than the ones before them. According to an engineering study, there is a 70% chance that at least one of these gyros will still work in the mid-2030s.

NASA is also looking into ways to lower the costs of running both Hubble and the Chandra X-ray Observatory. The goal is to find ways to save money while keeping the science output the same. Recommendations should come out later this summer based on an ongoing review of these activities.

There were talks about a possible private mission to service Hubble, including boosting its orbit. NASA and SpaceX studied in September 2022 to see if a journey like this could be done with a Crew Dragon spacecraft.

However, NASA has chosen not to pursue this option right now, citing risks like damage to the telescope and the difficulty of finding the technological solutions that would be needed. Clampin didn't say that this choice wouldn't be considered again, but he stressed that the long-term scientific benefits and short-term risks must be carefully balanced.

The Hubble Space Telescope has reached a turning point with its switch to one-gyro operations. This will ensure that its heritage of cosmic discoveries lives on.

Thanks to today's changes, Hubble's research power will be preserved for years. It will be able to work with next-generation telescopes like the James Webb Space Telescope and the soon-to-be-built Nancy Grace Roman Space Telescope.