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NASA's gamma-ray-burst alert satellite put into safe mode after suspected reaction wheel failure

To be fair, this is after 17 years of service in space

NASA has put its orbiting Neil Gehrels Swift Observatory into safe mode due to a suspected faulty reaction wheel, the first time this type of failure has occurred in its 17 years of operation.

NASA this week confirmed Swift was powered down on January 18. A team of scientists and engineers from Pennsylvania State University working at the Mission Operations Center (MOC) for Swift asked astronomers to hold off from requesting observation time as all science operations have temporarily halted.

“The mission team is investigating a possible failure of one of the spacecraft's reaction wheels as the cause,” NASA said in a statement. “The team has powered off the suspected wheel. The observatory and all its instruments are otherwise healthy and operating as anticipated. The observatory will remain in safe mode as a precaution while the team further investigates the issue.”

Swift has six reaction wheels that shift the platform to target gamma ray bursts and keep itself stable. With one wheel down, the team is trying to get the observatory up and running again with its five remaining wheels.

"Swift carries no consumables (eg, fuel) on-board, so end of life would occur either due to some critical hardware eventually failing, or the satellite will reenter the atmosphere," Brad Cenko, principal investigator for the Neil Gehrels Swift Observatory at NASA’s Goddard Space Flight Center, told The Register.

"The observatory has been successfully operating for over 17 years now, and re-entry is not anticipated until approximately the early 2030s, so our expectation is for many more years of great science going forward."

Swift was launched in 2004, and began its hunt for gamma-ray bursts in 2005. These bursts violently eject the most energetic forms of radiation and can last anywhere from several minutes to just a few milliseconds. Astronomers think they may be generated when a massive star collapses into a black hole or when two neutron stars collide.

“Swift caps off a 30-year hunt to understand the nature of gamma ray bursts, flashes of light that burn as brightly as a billion billion suns,” Anne Kinney, deputy center director of NASA's Goddard Space Flight Center, previously said.

“Swift is fine-tuned to quickly locate these bursts and study them in several different wavelengths before they disappear forever. Swift is a little satellite with a big appetite.”

Armed with not one but three different telescopes, Swift can observe these mysterious phenomena across gamma-ray, X-ray, ultraviolet, and optical wavelengths. Its Burst Alert Telescope (BAT) detects the explosions and logs the coordinates in space so that it can reorient to get a better look at what happened. Even after the gamma-ray burst event has ended, its X-ray telescope and Ultraviolet/Optical Telescope can continue to monitor the remaining afterglow.

Although these powerful bursts are pretty easy to spot, they’re difficult to study. Ground-based telescopes can’t observe the light emitted from the flares since the energetic waves are blocked by Earth’s atmosphere. Swift has made a number of discoveries over its lifetime, ranging from detecting one of the most distant gamma ray bursts discovered yet, the brightest cosmic event visible by the naked eye, to elusive intergalactic high-energy neutrinos. ®

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