NASA’s James Webb Space Telescope will see the first galaxies to be formed after the Big Bang, but to do that, its instruments must first be cold – real cold. On April 7, Webb’s Mid-Infrared Instrument (MIRI) —a joint development of NASA and ESA (European Space Agency) —reached its final working temperature below 7 kelvins (minus 447 degrees. Fahrenheit, or 266 degrees Celsius).
Along with Webb’s three other instruments, the MIRI first cooled in the shade of Webb’s large tennis court, which dropped to about 90 kelvins (less than 298 F, or 183 C). But a reduction to less than 7 kelvins requires an electric cryocooler. Last week, the company went through a difficult event called the “pinch point,” when the instrument went from 15 kelvins (minus 433 F, or 258 C) to 6.4 kelvins. (minus 448 F, or 267 C).
“The MIRI -inspired team has poured a lot of effort into developing the process for the pinch point,” said Analyn Schneider, project manager for MIRI at NASA’s Jet Propulsion Laboratory in Southern California. “The team was happy and excited about the hard work. As a result, it was a textbook of the process, and the work was much better than expected.”
Low temperature is necessary because Webb’s four sensors detect infrared light – the wavelength is much longer than what the naked eye can see. Distant stars, stars hidden in coconut fronds, and stars outside our solar system emit infrared light. But so are the other heaters, including Webb’s own electrical equipment and optics. The cooling of the four sensors and the surrounding technologies eliminates those infrared emissions. MIRI detects infrared wavelengths that are longer than the other three instruments, which means they need to be cooler.
One reason Webb’s detectors need to be cold is to detect something called darkness, or lightning created by the vibration of the powers in the detectors themselves. . Darkness is represented as a true signal to seers, giving the false impression that they have been struck by light from an external source. Such deceptive signals can eliminate the real signals that astronomers want to have. Because the higher the temperature of the vibration of the atoms in the sensor, the lower the temperature, the lower the vibration, which means the lower the vibration. the dark.
The ability of the MIRI to detect infrared waves is much easier than the blackout, so it needs to be cooler than other devices to properly detect that effect. For every degree the temperature of the instrument rises, the black current rises by a factor of 10.
When the MIRI reached 6.4 kelvins dry, scientists began a series of tests to verify that the sensors were working as expected. Just as a doctor looks for any sign of illness, the MIRI team looks at data that describes the health of the player, and then gives the player instructions to see if he or she can recover. perform tasks correctly. This milestone is the result of the work of scientists and engineers in several studios with JPL, including Northrop Grumman, who built the cryocooler, and NASA’s Goddard Space Flight Center, which oversaw the integration. Measurement of MIRI and the pleasure of the rest of the observatory. .
“We spent years training for that time, running the orders and evaluations that we did at MIRI,” said Mike Ressler, project scientist for MIRI at JPL. “It was like a movie: Everything we were supposed to do was written and executed.
The company faced many challenges before MIRI began its science career. Now that the instrument is at working temperature, team members will take test images of the stars and other sensors that can be used for calibration and observe the performance and performance. of the instrument. The company will lead these preparations with the calibration of the three instruments, releasing Webb’s first scientific photographs this summer.
“I am very proud to be part of this team of interesting, exciting scientists and engineers drawn from Europe and the US,” said Alistair Glasse, MIRI research scientist at the UK Astronomy Technology Center (ATC. ) and Edinburgh, Scotland. “This is our‘ trial on fire ’but I understand that the personal commitment and respect for someone that has been built over the years is what we will have in the coming months. provide a useful tool to the global astronomy community. ”
NASA’s Webb telescope will have the most comfortable camera in space
To learn more about Missionary Webb, visit: https://www.nasa.gov/webb
Courtesy of NASA’s Goddard Space Flight Center
Directions: The James Webb telescope’s coldest-to-average temperature (2022, April 13) retrieved April 13, 2022 from https://phys.org/news/2022-04-james-webb -telescope-coldest-instrument.html
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