NASA’s new space telescope continues to be colder.While James Webb Space Telescope, the telescope cooling process approaches the end, NASA officials write in the update, there is no strong timeline when all the observatory components will meet their operating temperatures. That is because most of the commission periods for months Telescope descended to physics, when the mission manager waited for a mirror to naturally cool the temperature to continue aligning.
All observatory instruments are at their final temperature, including the middle infrared instrument (Miri), which is very sensitive to heat and gets help from cryocooler to stay about 7 degrees Kelvin (minus 447 degrees Fahrenheit or minus 266 degrees Celsus). Webb needs to maintain the ultracool temperature to detect infrared light in the wavelength that emit heat.
However, the mirror, “Not enough there,” Jonathan Gardner, Webb of Senior Scientist Project Representatives, said in a renewal, which was posted on Thursday (April 21).That’s because 18 hexagonal segments of the main mirror, as well as secondary mirrors, are all made of beryllium and coated with gold. “At cryogenic temperatures, beryllium has a long thermal constant, which means it takes a long time to cool or heat up,” explained Gardner.
The $ 10 billion telescope has cooled since it was launched on December 25, 2021, and made good progress so far, Gardner said. All main mirror segments are under the 55 Kelvin sign (minus 360 F or minus 218 c) needed for Miri to operate. Further cooling “will only improve its performance,” Gardner said.Of the 18 main mirror segments, only four of them are above 50 Kelvin (minus 370 F or minus 223 C). Because these segments all have some middle infrared light that reach the Miri detector, the institution stated, officials prefer to see them cold with an additional 0.5 to 2 kelvin each before starting the next alignment phase.
This temperature is all subject to fluctuations, note the gardner. Telescope and Sunshield operate together when the telescope is aimed at something. There is a “small amount of heat,” he said, who can move through the sunlight five layers to the main mirror depending on the angle of Sunshield serving the sun, or attitude.Because the temperature of the mirror segment changes very slowly, their temperature depends on the average attitude for several days,” he said. In fact, Webb has spent most commissioning periods referring to the ecliptic poles, or the aircraft where the solar system planet orbits the sun.
This polar attitude, said Gardner, “is a relatively hot attitude.” But that is temporary, he added. “During science surgery, starting this summer, the telescope will have a much more indicating distribution above the sky. The thermal input on average to the hottest mirror segment is expected to drop a little, and the mirror will be cooler.”A little later in commissioning, added Gardner, the team plans to test the ability of the webb to switch from “hot attitude” to “cold attitude.” This thermal Slew process “will tell us how long we are for a mirror to cool or heat up when the observatory is in this position for a certain amount of time.”Webb still has to complete its commissioning around June, said Gardner. “Is the webb at the final temperature? The answer is almost,” he concluded.