In the Space center Johnson (Texas, USA) completed cryogenic testing of an orbital telescope “James Webb”. As the portal Space.com within 90 days the unit was in a closed vacuum cryogenic chamber with a constant temperature of -233 degrees Celsius. Cooling in the chamber was supported by two contours: the outer was filled with liquid nitrogen and the inner liquid helium.
Telescope “James Webb” is often called the successor to the space telescope “Hubble”. Both devices are similar problems, and both operate in the same frequency range. However, the “James Webb” is much (more than 6 times) larger than the old “Hubble”. It is so big that its primary mirror consists of 18 separate segments that need to be expanded as soon as the telescope gets to its destination of the Lagrange point L2 of the system Sun — Earth more than 1 million miles from Earth.
Tests in a vacuum chamber require careful preparation. Matter, while in low-pressure conditions inside the chamber can evaporate and settle down the condensation on a cooled surface of the telescope that can cause damage to its components. Therefore, prior to testing in a cryogenic chamber, NASA engineers had to literally clean it of every speck of dust. When the camera was finally prepared, it was placed a telescope and began a slow cooling, which lasted for a whole month.
“After 15 years of planning, testing, retrofitting the cryogenic chamber, hundreds of hours of testing designed to reduce the possibility of breakage of equipment as a result of the efforts of hundreds of professionals who worked for 90 days, tested in a cryogenic chamber completed successfully”, — said the head of the project to create an orbital telescope bill Ochs.
Testing did not prevent even the hurricane “Harvey” that struck Texas in August of this year and caused some serious damage in Houston, where is the Space center Johnson.
Now the telescope is transported to a test bench Northrop Grumman Aerospace Systems in Rodeo beach (California), where it will be docked the engine compartment. After that, the entire structure is subjected to a new series of tests on the vibration and overload.
Recall that the output of the telescope “James Webb” in orbit will be carried out in 2019 with the help of the carrier rocket Ariane 5 from Kourou in French Guiana. Within six months after the launch of all of its onboard equipment will be thoroughly checked, after which it can begin its primary mission, the observation of the oldest stars and galaxies in the Universe. The estimated period of operation of the telescope is 10 years.
Telescope “James Webb” passed cryogenic testing at -233 degrees Celsius
Nikolai Khizhnyak