It is almost three weeks that the Hubble Space Telescope went offline due to a glitch that, until now, NASA has yet to uncover. The space telescope launched in 1990 has halted its operations last June 13 at 4 pm EDT after a problem in one of its computers.

NASA said that since then, Hubble Space Telescope has stopped collecting science data, but its other hardware and science instruments remain in good health. They had also tried repairing the 1980s-era computer payload of the space telescope.

(Photo: Getty Images)
In this image released by the National Aeronautics and Space Administration (NASA), astronaut Richard M. Linnehan works to replace the starboard solar array on the Hubble Space Telescope (HST) during an extravehicular activity (EVA) to try and upgrade some components of the telescope March 4, 2002, in space. NASA plans to replace the Hubble telescope with the new James Webb Space Telescope (JWST) and plans to deorbit the Hubble telescope sometime in 2010. According to Anne Kinney, division director of astronomy and physics at NASA headquarters, NASA states August 1, 2003, that it is firmly committed to the new JWST, a deep-space observatory due for launch in 2011 on a European Ariane 5 rocket. (Photo by NASA/Getty Images)

Hubble Space Telescope's Backup Computer Having Troubles As Well

So far, controllers have managed to pinpoint some things that are not the culprit for why the space telescope went offline after their attempts of troubleshooting, according to ARS Technica. That helped them to narrow down possible reasons, but up to date, they still were not able to figure it out yet. For now, getting a diagnosis is their top priority.

Hubble Space Telescope is equipped with two 1980s-era payload computers that are both located on the Science Instrument and Command and Data Handling (SI C&DH) unit and installed in 2009.

One of them was the backups, which were turned on for the first time during the tests performed on June 23 and 24, according to Space.com. However, the engineers saw that even the backup is having the same troubles as the main computer.

Both primary and backup computers are designed to perform functions, such as processing and storing operational commands. They are also responsible for coordinating and controlling the science instruments of the Hubble Space Telescope and supporting communications between different components of the spacecraft.

The tests on June 23 and 24 showed that numerous combinations of hardware of the two computers experienced the same error in commands that write or read the memory, according to NASA.

As a result, NASA engineers still do not know what made the space telescope go offline. They are now investigating other hardware that may cause the issue, including the Command Unit/Science Data Formatter (CU/SDF) and the power regulator.

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NASA to Update Operations and Commands of Hubble Telescope

NASA team continues to scrutinize the Command Unit/Science Data Formatter (CU/SDF), a complex and riskier procedure than last time that involves switching to the backup payload computer hardware and memory modules.

According to NASA's statement, the team will review and update all operations procedures and commands to perform the switch to backup hardware. Then they will test their plan on a high-fidelity simulator to see if it will work.

They also did the same thing back in 2008 that allowed the space telescope to continue its normal science operations. Then in 2009, a servicing mission replaced the whole SI C&DH unit, including the CU/SDF module.

More than a decade later, Hubble Space Telescope has taken over 600,000 additional astronomical observations, exceeding its targeted 1.5 million observations, that continue to change human's understanding of the cosmos.

RELATED ARTICLE: Hubble Space Telescope Has Been Offline for a Week as NASA Fails to Fix It for the Third Time

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