The first servicing mission to the Hubble Telescope. Credit: NASA

Scientists Successfully Repair Hubble

Experts were uncertain whether Hubble will ever continue its scientific work.

NASA specialists have successfully transferred the Hubble Telescope to backup units responsible for the operation of scientific instruments. The source of the telescope’s failure was the electric power regulator in the power supply. Hubble should soon return to its glory days and continue its scientific work.

Chronology of the recent Hubble Telescope failures

1. In the summer of 2021, one of the largest disruptions in the Hubble Telescope’s operation occurred – starting from June 13, the telescope was in safe mode and did not conduct scientific observations.

2. Initially, it was assumed that the NSSC-1 computer, which is responsible for managing and coordinating the work of scientific instruments, failed, but its restart and attempts to switch to the backup memory unit did not work.

3. Then the attention of specialists turned to other suspects – the CU / SDF (Command Unit / Science Data Formatter) unit, which is responsible for formatting and sending commands and data, and the power supply control unit of the Hubble Telescope.

4. On July 14, after lengthy checks and various tests, NASA finally established the cause of the Hubble Telescope failure, which lay in the power control unit. It contains a power regulator that supplies five volts to the payload computer. If the voltage drops below or exceeds acceptable levels, the payload computer will automatically shut down.

5. The engineers came to the conclusion that either the regulator is out of order and constantly supplies an unacceptable voltage to the computer, or the computer’s secondary protection circuit has degraded and cannot get out of the prohibited state.

6. Since all the efforts of the specialists did not lead to the resumption of the power supply, it was decided to activate the previously planned procedure for switching to redundant modules, including a redundant power regulator.

7. The switch began on July 15, and a day later the agency reported that it was successful. Thereafter, the standby payload computer was powered on, loaded with flight software, and returned to normal operating mode.

8. Engineers are now monitoring the equipment to make sure everything is working correctly, as well as starting the process of restoring scientific instruments that are still in safe mode. After that, they will be calibrated, and only after that, the telescope will be able to return to full-fledged scientific work.

9. The Hubble Telescope has been in low-earth orbit for more than 30 years and it has been more than a decade since it received its last repair or upgrade. The last time astronauts were sent to the telescope was in 2009 when there was a malfunction in the CU / CDF module. Since then, there have been a number of failures that have been overcome without the need for an entire engineering mission.

10. Fortunately, the Hubble Telescope has survived yet another storm and will continue its observations. I believe it is imperative that it lasts until the next generation of telescopes begin operation. Not that there isn’t available data for another decade of analysis already but losing Hubble will be a sad day for science.

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Clery, D., Ibrahim, M., Fritts, R., Oza, A., & Viveros, A. (2021, July 16). ‘Hubble is back!’ Famed space telescope has new lease on life after computer swap appears to fix glitch. Science.
Gohd, C. (2021, July 16). NASA revives ailing Hubble Space Telescope with switch to backup computer.
HubbleSite. (n.d.). Operations Underway to Restore Payload Computer on NASA’s Hubble Space Telescope: Status Updates.
Jenner, L. (2021, June 16). NASA Returns Hubble Space Telescope to Science Operations. NASA.

Written by Vladislav Tchakarov

Hello, my name is Vladislav and I am glad to have you here on Curiosmos. As a history student, I have a strong passion for history and science, and the opportunity to research and write in this field on a daily basis is a dream come true.

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