NASA’s powerful $10 billion space telescope is firing at all cylinders again. The James Webb Space Telescope (JWST or Webb) returned to full science operations on Monday, January 30, after recovering from a malfunction affecting one of its instruments.

The Webb team has been testing and evaluating for several days since a “communication delay” on January 15 that caused problems with the telescope’s Near Infrared Imager and Slitless Spectrograph (NIRISS) instrument, according to a statement released Tuesday, January 31. (opens in new tabs) From NASA.

“Observations affected by the pause in NIRISS operations will be rescheduled,” the agency said in a brief statement, noting that the instrument was successfully restored on Friday, January 27.

NIRISS was provided by the Canadian Space Agency (CSA), so NASA and CSA staff worked together to fix the issues. According to a January 24 statement, the first issue was “a communication delay within the instrument” (opens in new tab) from NASA that caused the flight software to time out.

Normally, NIRISS can operate in four different modes, according to NASA. The instrument can be assigned to operate as a camera when other JWST instruments are busy. In addition, NIRISS can look at the light signatures of the atmospheres of small exoplanets, take high-contrast images or study distant galaxies.

Before the NIRISS failure in August 2022, there was a problem with another Webb instrument: the grating wheel inside the observatory’s infrared instrument (MIRI). But the wheel is only required for one of MIRI’s four observation modes, so the device continued to observe during rescue operations. Work to restore the affected mode, called Medium Resolution Spectrometer, was completed in November.

In December, the JWST team also spent two weeks solving an issue that kept the telescope in safe mode, making scientific observations difficult. The problem was determined to be a software bug in the observatory’s orientation control system that affected the direction the telescope was pointing. The observatory recovered from this problem relatively quickly and resumed its full scientific operations on 20 December.