Webb Space Telescope Glitch Likely Caused by Galactic Cosmic Ray – NIRISS Returns to Full Operations

The James Webb Space Telescope

Revealed: The Secrets our Clients Used to Earn $3 Billion

In addition to distant stars, galaxies and exoplanets, the NASA/ESA/CSA James Webb Space Telescope will examine our Solar System. Credit: Northrup Grumman

On January 15, NASA’s James Webb Space Telescope’s Near Infrared Imager and Slitless Spectrograph (NIRISS) experienced a communications delay within the science instrument, causing its flight software to time out. Following a full investigation by NASA and Canadian Space Agency (CSA) teams, the cause was determined to likely be a galactic cosmic ray, a form of high-energy radiation from outside our solar system that can sometimes disrupt electrical systems. Encountering cosmic rays is a normal and expected part of operating any spacecraft. This cosmic ray event affected logic in the solid-state circuitry of NIRISS electronics known as the Field Programmable Gate Array. Webb engineers determined that rebooting the instrument would bring it back to full functionality.

After completing the reboot, NIRISS telemetry data demonstrated normal timing, and to fully confirm, the team scheduled a test observation. On January 28, the Webb team sent commands to the instrument to perform the observation, and the results confirmed on January 30 NIRISS is back to full scientific operations.

James Webb Space Telescope NIRISS Infographic Crop

(Click image for view of full infographic.) The Near-Infrared Imager and Slitless Spectrograph (NIRISS) is one of Webb’s four scientific instruments. NIRISS provides near-infrared imaging and spectroscopic capabilities. As the only instrument capable of aperture mask interferometry, NIRISS has the unique ability to capture images of bright objects at a resolution greater than the other imagers. NIRISS is a contribution of the Canadian Space Agency. Honeywell International designed and built the instrument in collaboration with a team at the Université de Montréal. Additional technical support was provided by the National Research Council of Canada’s Herzberg Astronomy and Astrophysics Research Centre. Credit: NASA, ESA, Andi James (STScI)

“NASA and 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. When performing the operation, reviews were held at each intermediate step. 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.