The James Webb Space Telescope’s ultra-cool MIRI camera is back in full science after a technical problem on the retina wheel forced scientists to stop some observations.
The grooved wheel on the Medium Resolution Spectrometer (MRS) from James Webb Space TelescopeThe Mid-Infrared Instrument (MIRI) allows astronomers to choose wavelengths of light to observe the ocean Universe. The wheel, which is used in only one of MIRI’s four observation modes, began showing signs of friction in August, forcing the mission team to suspend observations in the affected position.
After weeks of remote scrutiny, engineers concluded that the problem was caused by “increased contact forces between the central bearing assembly subcomponents of the wheel under certain conditions,” the Space Telescope Science Institute (STScI) in Baltimore, which is responsible for Webb’s operations, said in statement (Opens in a new tab).
STScI said in the statement that engineers have now given the green light for affected spectroscopy mode to resume operations and are developing a set of recommendations on how to use the affected wheel safely.
“An engineering test demonstrating new operational parameters for the grid wheel mechanism was successfully carried out on November 2, 2022,” STScI said in the statement. “MIRI will resume MRS scientific observations, including taking advantage of a unique opportunity to observe the polar regions of Saturn. The JWST team will schedule additional MRS scientific observations, initially at a highly coordinated cadence with additional directional measurements to observe the new mechanism’s operational system to prepare MIRI’s MRS mode to return to Full scientific scheduling.”
When operating in MRS mode, Mary It captures not images but spectra of light, which are light-absorbing fingerprints that reveal the chemical compositions of the observed objects.
The other three MIRI monitoring modes—imaging, coronary imaging, and low-resolution spectroscopy—continued as usual during the MRS interruption. The ultra-cool camera showed its power with a range of stunning images including a creative shot Pillars of Creationwhich revealed the complex earthy composition in frightening detail.
MIRI, which specializes in detecting mid-infrared wavelengths, requires the coldest temperatures of all Webb’s devices to work accurately. While the other three instruments — NIRCam, NIRSpec and FGS/NIRISS — rely on the telescope’s location and its giant sun mantle to keep temperatures below minus 369.4 degrees Fahrenheit (minus 223 degrees Celsius), MIRI requires additional cooling coolers to reach a cooler temperature. minus 447 degrees Fahrenheit (266 degrees Celsius). That’s just 12 degrees Fahrenheit (7 degrees Celsius) above absolute zero, the temperature at which the movement of atoms stops. Since MIRI detects infrared light, which is essentially heat, any additional warmth would reduce the sensitivity of its measurements.
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