A science instrument on the James Webb Space Telescope (JWST) has been switched off and on again by NASA engineers after the spacecraft was struck by galactic rays, according to the space agency.
A blog post reveals that on Jan. 15 the telescope’s Near Infrared Imager and Slitless Spectrograph (NIRISS) instrument was impacted by high-energy radiation from outside our solar system, disrupting its communications equipment.
NIRISS is crucial to JWST because it can analyze the atmospheres of distant exoplanets. So far it’s helped find carbon dioxide in the atmosphere of WASP-39b, a hot gas-giant orbiting a Sun-like star about 700 light-years from Earth.
Its set to revolutionize scientists’ understanding of exoplanets and their atmospheres—and could help reveal an Earth-like world.
However, after the incident NIRISS was unable to communicate properly so was rebooted—switched off and on again—remotely by NASA engineers. After a successful test on Jan. 28, NIRISS was doing science again by Jan. 30.
All science observations affected by the outage will be rescheduled, said NASA.
“We are now happy to report that Webb’s NIRISS instrument is back online, and is performing optimally,” said Julie Van Campen, Webb Integrated Science Instrument Module (ISIM) systems engineer at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “NASA and the Canadian Space Agency (CSA) partnered to approach the problem as technically possible, using a detailed consideration of all areas of operation of the instrument. They analyzed all possible methods to safely recover the electronics.”
Encountering cosmic rays is a normal and expected part of operating any spacecraft, said NASA.
In November 2022, NASA admitted that JWST had been struck 14 times by micrometeoroids, tiny particles of space dust, permanently damaging its 18 beryllium-gold segments.
Over the next two years the JWST will fly through dust and debris left in the inner solar system by Halley’s comet. It could mean JWST being manoeuvred to point away from the incoming particles, thus preventing them from striking the mirrors.
JWST is the most ambitious and complex space science telescope ever constructed, with a massive 6.5-meter primary mirror that will be able to detect the faint light of far-away stars and galaxies.