by Every spacecraft falters from time to time, and even the most powerful space telescope ever launched is not immune.
The James Webb Space Telescope (JWST or Webb) was launched in December 2021 and has been conducting scientific observations since July 2022, stunning the world with its beautiful images and revolutionary data. But on Jan. 15, JWST’s Near Infrared Imager and Slitless Spectrograph (NIRISS) instrument “experienced a communications delay within the instrument, causing the flight software to time out,” according to a Jan. 24 statement. (opens in new tab) from NASA. NIRISS cannot currently be used for science, the statement said.
“There is no indication of any danger to the hardware, and the observatory and other instruments are all in good health,” NASA officials wrote. “The affected scientific observations will be rescheduled.”
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NIRISS is a contribution from the Canadian Space Agency (CSA), so NASA and CSA personnel are working together to solve the problem, the statement said.
Under normal circumstances, NIRISS can operate in four different modes (opens in new tab), according to NASA. It can operate as a camera when JWST’s other instruments are busy, it can analyze light signatures to study the atmospheres of small exoplanets, it can perform high-contrast imaging, and it has a mode tuned for finding distant galaxies.
NIRISS is not the first instrument on JWST to run into trouble. In August, a grating wheel in the observatory’s Mid-Infrared Instrument (MIRI) began showing signs of rubbing. The wheel is only used in one of the instrument’s four observation modes, so staff paused those observations while MIRI work continued in the other three modes.
By November, engineers had tracked down the source of the problem and began developing guidelines for safe use of the affected mode, called the Medium Resolution Spectrometer.
In addition, the observatory was plagued for two weeks in December by a glitch that repeatedly sent the telescope into safe mode, interrupting scientific observations. Engineers traced the problem to a software bug in the observatory’s attitude control system, which controls the spacecraft’s direction.
The observatory returned to normal operation from then on Dec. 20, according to a then-NASA statement.
The NIRISS announcement came exactly one year after JWST arrived at its outpost, Earth-sun Lagrange point 2, which is nearly 1 million miles (1.5 million kilometers) from Earth on the side opposite the sun.
Email Meghan Bartels at mbartels@space.com or follow her on Twitter @meghanbartels. follow us on Twitter @spacedot com and further Facebook.
