NASA is finally preparing to launch the James Webb Space Telescope on December 18



alex-mit via Getty Images (elements furnished by NASA)

Originally scheduled to be assembled in 2016, NASA’s new-generation James Webb Space Telescope (JWST) launched in 2018 was delayed and delayed due to long-term technical difficulties. The assembly was not completed until the end of 2019, and then due to the epidemic and “remaining work “The risk analysis of the test project” was first postponed to March 2021, and then postponed to the end of October 2021. Now after another delay, NASA finally has a definite launch date, which is set on December 18, which will be launched by ESA’s Ariane 5 rocket. Before that, NASA had to safely send the telescope to French Guiana where it was launched, and then integrate it with the rocket.

JWST has always been called “Hubble’s successor”, but in fact its observation frequency band is biased towards infrared, unlike Hubble which is dominated by visible light. Because of this difference, JWST is very different from Hubble in appearance and track. In order to prevent the heat from the sun and the earth from obstructing observations, and to keep the instrument’s low temperature of -223 degrees, JWST will be launched to the L2 Lagrangian point, and there will be multiple layers of “metal sun visors” facing the sun and the earth. Let the telescope itself not be affected by heat. However, the folding and unfolding mechanism of these sun visors has made engineers irritated, and it will also make JWST beyond the scope of the earth’s “maintenance”, unable to send tasks to make corrections like Hubble back then. Therefore, for JWST, the pressure not to make mistakes is much greater.

JWST’s stated mission length is only 5 years, but NASA hopes it can work in orbit for 10 years. However, since it is impossible to repair and upgrade, it is basically impossible to survive for more than 30 years like Hubble.