posted 11-30-2023 08:36 AM               

Hubble Space Telescope Pauses Science Due to Gyro Issue

NASA is working to resume science operations of the agency's Hubble Space Telescope after it entered safe mode Nov. 23 due to an ongoing gyroscope (gyro) issue. Hubble's instruments are stable, and the telescope is in good health.

The telescope automatically entered safe mode when one of its three gyroscopes gave faulty readings. The gyros measure the telescope's turn rates and are part of the system that determines which direction the telescope is pointed. While in safe mode, science operations are suspended, and the telescope waits for new directions from the ground.

Hubble first went into safe mode Nov. 19. Although the operations team successfully recovered the spacecraft to resume observations the following day, the unstable gyro caused the observatory to suspend science operations once again Nov. 21. Following a successful recovery, Hubble entered safe mode again Nov. 23.

The team is now running tests to characterize the issue and develop solutions. If necessary, the spacecraft can be re-configured to operate with only one gyro. The spacecraft had six new gyros installed during the fifth and final space shuttle servicing mission in 2009. To date, three of those gyros remain operational, including the gyro currently experiencing fluctuations. Hubble uses three gyros to maximize efficiency, but could continue to make science observations with only one gyro if required.

NASA anticipates Hubble will continue making groundbreaking discoveries, working with other observatories, such as the agency's James Webb Space Telescope, throughout this decade and possibly into the next.

posted 12-08-2023 01:01 PM               

NASA’s Hubble Space Telescope Returns to Science Operations

NASA restored the agency’s Hubble Space Telescope to science operations Friday, Dec. 8. The telescope had paused science observations Nov. 23 due to an issue with one of its gyros. The spacecraft is in good health and once again operating using all three of its gyros.

Based on the performance observed during tests, the team decided to operate the gyros in a higher-precision mode during science observations.

Hubble’s two main cameras, Wide Field Camera 3 and Advanced Camera for Surveys, resumed science observations Friday. The team is planning to restore operations to the Cosmic Origins Spectrograph and Space Telescope Imaging Spectrograph later this month.

posted 04-29-2024 08:38 AM               

NASA's Hubble Pauses Science Due to Gyro Issue

NASA is working to resume science operations of the agency's Hubble Space Telescope after it entered safe mode April 23 due to an ongoing gyroscope (gyro) issue. Hubble's instruments are stable, and the telescope is in good health.

The telescope automatically entered safe mode when one of its three gyroscopes gave faulty readings. The gyros measure the telescope's turn rates and are part of the system that determines which direction the telescope is pointed. While in safe mode, science operations are suspended, and the telescope waits for new directions from the ground.

This particular gyro caused Hubble to enter safe mode in November after returning similar faulty readings. The team is currently working to identify potential solutions. If necessary, the spacecraft can be re-configured to operate with only one gyro, with the other remaining gyro placed in reserve. The spacecraft had six new gyros installed during the fifth and final space shuttle servicing mission in 2009. To date, three of those gyros remain operational, including the gyro currently experiencing fluctuations. Hubble uses three gyros to maximize efficiency, but could continue to make science observations with only one gyro if required.

posted 04-30-2024 07:14 PM               

On April 30, 2024, NASA announced it restored the agency's Hubble Space Telescope to science operations April 29. The spacecraft is in good health and once again operating using all three of its gyros. All of Hubble’s instruments are online, and the spacecraft has resumed taking science observations.

posted 06-03-2024 01:07 PM               

NASA's Hubble Temporarily Pauses Science

NASA's Hubble Space Telescope entered safe mode May 24 due to an ongoing gyroscope (gyro) issue, suspending science operations. Hubble's instruments are stable, and the telescope is in good health.

The telescope automatically entered safe mode when one of its three gyroscopes gave faulty telemetry readings. Hubble's gyros measure the telescope's slew rates and are part of the system that determines and controls precisely the direction the telescope is pointed.

posted 06-04-2024 03:06 PM               

NASA to Change How It Points Hubble Space Telescope

After completing a series of tests and carefully considering the options, NASA announced Tuesday work is underway to transition its Hubble Space Telescope to operate using only one gyroscope (gyro). While the telescope went into safe mode May 24, where it now remains until work is complete, this change will enable Hubble to continue exploring the secrets of the universe through this decade and into the next, with the majority of its observations unaffected.

Of the six gyros currently on the spacecraft, three remain active. They measure the telescope's slew rates and are part of the system that determines and controls the direction the telescope is pointed. Over the past six months, one particular gyro has increasingly returned faulty readings, causing the spacecraft to enter safe mode multiple times and suspending science observations while the telescope awaits new instructions from the ground.

This one gyro is experiencing "saturation," where it indicates the maximum slew rate value possible regardless of how quickly the spacecraft is slewing. Although the team has repeatedly been able to reset the gyro's electronics to return normal readings, the results have only been temporary before the problem reappears as it did again in late May.

To return to consistent science operations, NASA is transitioning the spacecraft to a new operational mode it had long considered: Hubble will operate with only one gyro, while keeping another gyro available for future use.

The spacecraft had six new gyros installed during the fifth and final space shuttle servicing mission in 2009. To date, three of those gyros remain operational, including the gyro currently experiencing problems, which the team will continue to monitor. Hubble uses three gyros to maximize efficiency but can continue to make science observations with only one gyro.

NASA first developed this plan more than 20 years ago, as the best operational mode to prolong Hubble's life and allow it to successfully provide consistent science with fewer than three working gyros. Hubble previously operated in two-gyro mode, which is negligibly different from one-gyro mode, from 2005-2009. One-gyro operations were demonstrated in 2008 for a short time with no impact to science observation quality.

While continuing to make science observations in one-gyro mode, there are some expected minor limitations. The observatory will need more time to slew and lock onto a science target and won't have as much flexibility as to where it can observe at any given time. It also will not be able to track moving objects closer than Mars, though these are rare targets for Hubble.

The transition involves reconfiguring the spacecraft and ground system as well as assessing the impact to future planned observations. The team expects to resume science operations again by mid-June. Once in one-gyro mode, NASA anticipates Hubble will continue making new cosmic discoveries alongside other observatories, such as the agency's James Webb Space Telescope and future Nancy Grace Roman Space Telescope, for years to come.

posted 06-17-2024 09:55 AM               

Hubble Restarts Science in New Pointing Mode

NASA successfully transitioned operations for the agency's Hubble Space Telescope to an alternate operating mode that uses one gyro, returning the spacecraft to daily science operations Friday. The telescope and its instruments are stable and functioning normally.

Hubble went into safe mode May 24 due to an ongoing issue with one of its gyroscopes (gyros), which measure the telescope's slew rates and are part of the system that determines and controls the direction the telescope is pointed. The gyro had been increasingly returning faulty readings over the past six months, suspending science operations multiple times. This led the Hubble team to transition from a three-gyro operating mode to observing with only one gyro, enabling more consistent science observations and keeping another operational gyro available for future use.

The team will continue monitoring the problematic gyro to see if it stabilizes and can be used again in the future. Although there are some minor limitations to observing in one-gyro mode, Hubble can continue doing most of its science observations. Further refinements to optimize operations are anticipated as the team gains more experience with the one-gyro mode.

Launched in 1990, Hubble has more than doubled its expected design lifetime, and has been observing the universe for more than three decades, recently celebrating its 34th anniversary.