The MIRI instrument of the James Webb Space Telescope has cooled to minus -266 degrees Celsius. MIRI was the last part to cool off, and with that James Webb was ready for calibration.
James Webb has been cooling down to absolute zero since its December 25 launch, and the latest device recently reached its final temperature. NASA announced this achievement In this week† The space agency says the MIRI instrument reached a temperature of 7 K, or -266 degrees Celsius, on April 7. With this, James Webb is completely at the temperature level and the MIRI calibration can begin.
To achieve that temperature, electric cooler† The other 3 Webb tools are pre-cooled by sun shield The size of a tennis court, with a temperature of about -233 degrees Celsius. However, the MIRI, or mid-infrared instrument, needs a temperature of -267 degrees Celsius to detect infrared light.
Infrared radiation is thermal radiation. NASA explains that planets, galaxies, and stars all emit infrared light, as do other warm objects. The telescope’s cooling prevents James Webb’s components from emitting infrared radiation that interferes with its operation. MIRI detects infrared light with a longer wavelength than the other three devices, and therefore must be cooler. This cannot be achieved with the aforementioned passive cooling and solar shielding. That is why a cryogenic coolant is used, which cools MIRI with helium gas. Tweakers wrote earlier Background story on MIRIA and its active cooling.
Now that the telescope is cool, that doesn’t mean Webb can work right away. In the near future, team members will first create test images of stars and other known objects, which can be used for calibration and to check the operation and functionality of MIRI. NASA will be making these preparations along with the calibration of the other three instruments, so hopefully Webb will present his first images this summer.
“Total coffee specialist. Hardcore reader. Incurable music scholar. Web guru. Freelance troublemaker. Problem solver. Travel trailblazer.”