{"type":"video","version":"1.0","provider_name":"Dailymotion","provider_url":"https:\/\/www.dailymotion.com","title":"Why Webb Needs a Sunshield\u2014and a Refrigerator","description":"Webb is built to detect faint infrared light, so the observatory has to limit both heat from warm surfaces and heat-generated charge inside its detectors. Its five-layer sunshield reduces heat reaching the telescope. Three instruments cool mainly through passive radiative cooling; MIRI uses a helium cryocooler for its colder operating requirement.NASA reported that MIRI reached 6.4 K on April 7, 2022, during commissioning (reported April 13). That is a dated measurement for MIRI, not a live temperature for Webb as a whole. The milestone did not by itself validate scientific performance. System diagrams in this video are schematic and do not claim exact as-built helium routing.Chapters:00:00 Title \/ Chapter 01 \u2014 A faint signal under a warm glow01:35 What the telescope adds to the signal02:50 Why a vacuum is not a refrigerator04:51 Five layers divide the heat problem07:36 Cold and steady are different requirements09:01 Passive cooling for three instruments10:05 Why MIRI needs a colder detector11:59 A refrigerator spread across Webb13:52 Cooling without blurring the telescope15:26 The commissioning descent to 6.4 kelvins16:56 What cold solves\u2014and what it cannot18:06 The answer, from warm side to detectorSources and further reading:https:\/\/science.nasa.gov\/mission\/webb\/science-overview\/science-explainers\/telescope-overview\/https:\/\/science.nasa.gov\/asset\/webb\/webb-telescope-spacecraft-diagram\/https:\/\/science.nasa.gov\/mission\/webb\/webbs-sunshield\/https:\/\/science.nasa.gov\/mission\/webb\/cryocooler\/https:\/\/www.nasa.gov\/solar-system\/webb-telescopes-coldest-instrument-reaches-operating-temperature\/https:\/\/science.nasa.gov\/mission\/webb\/science-overview\/science-explainers\/how-does-webb-stay-cold\/YouTube release: https:\/\/www.youtube.com\/watch?v=ZSBu4q4kYFAProduced by GreenSpacealien.Find us on:Facebook: https:\/\/www.facebook.com\/profile.php?id=61594406836899Instagram: https:\/\/www.instagram.com\/greenbigspacealien15\/X: https:\/\/x.com\/GreenSpacealieTikTok: https:\/\/www.tiktok.com\/@greenbigspace15Reddit: https:\/\/www.reddit.com\/r\/GreenSpacealien15\/Dailymotion: https:\/\/www.dailymotion.com\/user\/green.hbw590Pinterest: https:\/\/www.pinterest.com\/greenbigspacealien15\/Rumble: https:\/\/rumble.com\/user\/greenspacealien15Threads: https:\/\/www.threads.com\/@greenbigspacealien15Bluesky: https:\/\/bsky.app\/profile\/greenspacealien15.bsky.social","author_name":"Green Space","author_url":"https:\/\/www.dailymotion.com\/green.hbw590","width":480,"height":269,"html":"<iframe frameborder=\"0\" width=\"480\" height=\"269\" src=\"https:\/\/geo.dailymotion.com\/player.html?video=xbs8k32&\" allowfullscreen allow=\"autoplay; fullscreen; picture-in-picture; web-share\"><\/iframe>","thumbnail_url":"https:\/\/s1.dmcdn.net\/v\/gUB-k1gvJvkWt-nuB\/x720","thumbnail_width":1281,"thumbnail_height":720}