{"id":23761,"date":"2022-07-27T09:27:13","date_gmt":"2022-07-27T13:27:13","guid":{"rendered":"http:\/\/www.monsffa.ca\/?p=23761"},"modified":"2022-07-22T09:32:01","modified_gmt":"2022-07-22T13:32:01","slug":"micrometeoroid-damage-to-james-webb-space-telescope-imaged-for-first-time","status":"publish","type":"post","link":"https:\/\/www.monsffa.ca\/?p=23761","title":{"rendered":"Micrometeoroid damage to James Webb Space Telescope imaged for first time"},"content":{"rendered":"
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\u00a0The damage to NASA’s flagship observatory was significantly greater than pre-launch expectations.<\/em><\/p>\n
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By The Physics arXiv Blog<\/a> \u00a0|\u00a0 Published: Friday, July 15, 2022<\/div>\n
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\"JWSTillustration\"<\/a>
Dotted Yeti\/Shutterstock<\/figcaption><\/figure>\n

The micrometeoroid that hit the James Webb Space Telescope<\/a> in May caused significantly more damage than expected and will have a lasting impact on the telescope\u2019s observations, according to a NASA report on the spacecraft\u2019s performance<\/a>. By contrast, other micrometeoroid impacts during the spacecraft\u2019s first six months of operation have had a negligible effect.<\/div>\n

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The report contains an image showing the damage to one hexagonal segment of the observatory\u2019s main mirror, called C3. \u201cThe single micrometeorite impact that occurred between 22\u201424 May 2022 exceeded prelaunch expectations of damage for a single micrometeoroid,\u201d says the NASA report.<\/p>\n<\/div>\n<\/div>\n

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\"JWSTmirrordamage\"<\/a><\/div>\n
Spot the difference: infrared images of the James Webb Space Telescope before launch (left) and after the micrometeoroid strike (right). The damaged C3 segment is to the bottom right of the mirror.<\/div>\n
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“Characterization of JWST science performance from commissioning” (July 12, 2022); NASA\/ESA\/CSA<\/div>\n<\/div>\n<\/div>\n
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The performance of the main mirror is determined by how much it deforms incoming starlight and measured by a quantity called wavefront error rms (root mean square). At the beginning the mission, the C3 segment had a wavefront error of 56 nanometers rms, a level similar to the main mirror\u2019s other 17 segments. The impact increased C3\u2019s wavefront error to 258 nm rms.<\/p>\n

Spacecraft engineers can change the position and curvature of each segment and in this way were able to reduce the error to 178 nm rms. This has a measurable effect on the error of the main mirror as a whole. \u201cHowever, the effect was small at the full telescope level because only a small portion of the telescope area was affected,\u201d says the report.<\/p>\n

The JWST team say the impact increased the error associated with entire main mirror to about 59 nm rms. \u201cAbout 5-10 nm rms above the previous best wavefront error rms values.\u201d That\u2019s well within the performance limits the team were hoping for.<\/p>\n

Nevertheless, the impact raises questions about the nature of the space environment where the JWST operates. This is a point in space about a million kilometers from Earth where the gravitational fields of the Sun, Moon and Earth are in balance and so provide a relatively stable location.<\/p>\n<\/div>\n

READ MORE https:\/\/astronomy.com\/news\/2022\/07\/micrometeoroid-damage-to-james-webb-space-telescope-imaged-for-first-time?<\/a><\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

\u00a0The damage to NASA’s flagship observatory was significantly greater than pre-launch expectations. By The Physics arXiv Blog \u00a0|\u00a0 Published: Friday, July 15, 2022 The micrometeoroid that hit the James Webb Space Telescope in May caused significantly more damage than expected and will have a lasting impact on the telescope\u2019s observations, according to a NASA report … Continue reading Micrometeoroid damage to James Webb Space Telescope imaged for first time<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":645,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[133],"tags":[1680,1681],"class_list":["post-23761","post","type-post","status-publish","format-standard","hentry","category-astronomy-news","tag-james-webb-telescope","tag-micrometeoroid"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.monsffa.ca\/index.php?rest_route=\/wp\/v2\/posts\/23761","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.monsffa.ca\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.monsffa.ca\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.monsffa.ca\/index.php?rest_route=\/wp\/v2\/users\/645"}],"replies":[{"embeddable":true,"href":"https:\/\/www.monsffa.ca\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=23761"}],"version-history":[{"count":1,"href":"https:\/\/www.monsffa.ca\/index.php?rest_route=\/wp\/v2\/posts\/23761\/revisions"}],"predecessor-version":[{"id":23763,"href":"https:\/\/www.monsffa.ca\/index.php?rest_route=\/wp\/v2\/posts\/23761\/revisions\/23763"}],"wp:attachment":[{"href":"https:\/\/www.monsffa.ca\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=23761"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.monsffa.ca\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=23761"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.monsffa.ca\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=23761"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}