IRIA News

NASA’s James Webb Space Telescope is one step closer to being fully commissioned as its Mid-Infrared Instrument (MIRI) reached its final operating temperature below 7 kelvins (minus 447 degrees Fahrenheit, or minus 266 degrees Celsius).

The MIRI of the James Webb Space Telescope has been jointly developed by NASA and European Space Agency. According to the NASA release, “MIRI initially cooled off in the shade of Webb’s tennis-court-size sunshield, dropping to about 90 kelvins (minus 298 F, or minus 183 C). But dropping to less than 7 kelvins required an electrically powered cryocooler. Last week, the team passed a particularly challenging milestone called the “pinch point,” when the instrument goes from 15 kelvins (minus 433 F, or minus 258 C) to 6.4 kelvins (minus 448 F, or minus 267 C).

Chief Engineer of James Webb Space Telescope at Northrop Grumman, Charlie Atkinson said “Reaching MIRI’s operational temperature is a major step toward science and all the astounding discoveries Webb will uncover for years to come. The success of this remarkable milestone is a testament to the dedication of engineers and scientists and the many years of practice.”

Project manager for MIRI at NASA’s Jet Propulsion Laboratory in Southern California, Analyn Schneider said “The MIRI cooler team has poured a lot of hard work into developing the procedure for the pinch point. The team was both excited and nervous going into the critical activity. In the end, it was a textbook execution of the procedure, and the cooler performance is even better than expected.”

After reaching the milestone, project scientist for MIRI at NASA’s Jet Propulsion Laboratory, Mike Ressler said “We spent years practicing for that moment, running through the commands and the checks that we did on MIRI. It was kind of like a movie script: Everything we were supposed to do was written down and rehearsed. When the test data rolled in, I was ecstatic to see it looked exactly as expected and that we have a healthy instrument.”

According to the Northrop Grumman release, James Webb’s cryocooler is an advanced machine that operates as an internal refrigerator to establish and maintain the right cryogenic temperature for the MIRI.

“The cryocooler keeps sensors extremely cold so the MIRI can observe the skies and capture light from billions of years ago. To date, Northrop Grumman has delivered over 50 space flight cryocoolers with an accumulated 300 years of combined on-orbit operations,” the statement read.

As the telescope reaches operating temperature, the next step for the team members will be to take test images of stars and other known objects that can be used for calibration and to check the instrument’s operations and functionality.

NASA statement highlighted that the team will conduct these preparations alongside calibration of the other three instruments, delivering Webb’s first science images this summer.

Designed as a replacement for the Hubble Telescope, James Webb far exceeds the abilities and capabilities of its 1990-built predecessor. James Webb is bigger in size and far well equipped with complex instruments compared to Hubble. The visible spectrum of James Webb includes not only electromagnetic radiation but also infrared radiation allowing the telescope to capture much more and much precise information in further space, which is a major up-gradation from its predecessor. It is also equipped with a high-end radiation shield and cooling equipment that would ensure the equipment’s safety from solar radiation.

James Webb can see deeply throughout that space and pick up light and radiation signals which are 10 billion times fainter than the dimmest star a person can see with a naked eye in a clear night sky. That is 100 times fainter than anything that Hubble can pick up. A NASA official at the launch site described Webb’s vision to be so sharp that it can see details off of a penny from 40 km away.

James Webb’s core goals include searching for the first stars and galaxies that formed after the Big Bang, shining a light on galactic evolution and planet formation, and helping to characterize nearby exoplanet systems, especially those that may be capable of supporting life as we know it.