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<\/p>\n While MSFC carry out work on the Backplane Structural Test Article, an ambiguous NASA memo from the Goddard Space Center noted: \u2018JWST experienced a machining issue. A review team has been put together and processing of the engineering unit is continuing.\u2019<\/p>\n <\/font><\/p>\n The seriousness is as yet unknown, although that hasn\u2019t halted MSFC\u2019s testing of the anchor for the 18-segment mirror that will utilise its powerful infrared optics. The backplane test article, a lightweight composite material, was built by project subcontractor ATK Thiokol Propulsion.<\/font><\/p>\n \u2018It\u2019s about as cold as a machine can get and continue to function,\u2019 said Kevin Russell, element lead for the James Webb project at Marshall. <\/p>\n \u2018At minus 459 degrees, or \u2018absolute zero,\u2019 the kinetic motion of subatomic particles simply ceases. That\u2019s nearly the chill factor the James Webb will experience at its orbital destination \u2013 some 932,000 miles from Earth.<\/font><\/p>\n \u2018There, the deep cold of space can deform structural materials and warp ultra-sensitive optics. That\u2019s why cryogenic testing on the ground is vital to the telescope\u2019s optics and support structure.<\/p>\n \u2018These inverse-deformities are apparent at normal, sea-level temperatures. In the icy reaches of space, however, the planned cryogenic deformation shifts the elements back into perfect alignment.<\/font><\/p>\n \u2018Such meticulous analysis and precision fabrication is essential to mission success. When the James Webb reaches its planned orbit, it will be four times the distance from Earth to the moon. There will be no chance for a do-over later.\u2019<\/p>\n MSFC\u2019s 6,000 square foot X-ray Calibration Facility is over 30 years old, but was upgraded in 1989 to calibrate NASA\u2019s Chandra X-ray Observatory, which was launched into space on one of the late Shuttle Columbia\u2019s numerous flagship missions.<\/font><\/p>\n The largest optical test site in the world, the facility is NASA\u2019s primary resource for horizontal vacuum testing of large-scale optics systems \u2013 housing to the 24-foot-diameter, 75-foot long stainless steel chamber, which can accommodate in-flight configurations of any payload to be launched from the space shuttle. The facility will begin receiving some of the 18 primary mirror segments for testing in 2007.<\/font><\/p>\n Spaceflight news subscription (adsbygoogle = window.adsbygoogle || []).push({});<\/p>\n \u2018Each primary mirror segment will be tested twice over the next four years,\u2019 noted Jeff Kegley, team lead for the X-ray Calibration Facility, \u2018once to determine how much the mirror deforms at extremely cold temperatures and again to ensure improper deformations are corrected.\u2019<\/font><\/p>\n From its orbital home at L2, one of five points identified by and named for 18th century mathematician Joseph-Louis Lagrange \u2013 where the gravitational pull of Earth and the sun balance one another \u2013 the telescope will have a clear sightline into our past. <\/p>\n Lagrange sites naturally deliver the centripetal force necessary to keep a satellite rotating in sync with Earth without excessive on board power requirements.<\/p>\n The L2 position enables JSWT to utilise its giant sun shield \u2013 half the size of a football pitch \u2013 to block out the Sun\u2019s heat along with reflected light from Earth and the moon. <\/p>\n This shielding permits the telescope to focus accurately on faint astronomical signals from the depths of space, and ultimately deliver far more penetrating infrared studies of the ancient cosmos than ever before possible.<\/p>\n Article collated from L2 information and MSFC\u2019s Marshall Star internal magazine (Rick Smith). Image: David Higginbotham\/MSFC.<\/em><\/p>\n <\/font> **NASASpaceflight.com Job Opportunities**<\/em><\/font> <\/u><\/p>\n <\/em><\/font><\/p>\n <\/font><\/p>\n","protected":false},"excerpt":{"rendered":" The NASA Marshall Space Flight Center (MSFC) has begun simulated space environment testing on a key element of the James Webb Space Telescope (JWST), which has suffered its fair share of development problems. The state of the art telescope is due to launch on an Ariane 5 in 2013, for an orbital destination nearly a […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[],"class_list":["post-41957","post","type-post","status-publish","format-standard","hentry","category-news"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/41957"}],"collection":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/comments?post=41957"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/41957\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=41957"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=41957"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=41957"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}<\/em><\/font><\/font><\/p>\n
According to August 31\u2019s Marshall Star<\/em> \u2013 the internal magazine for MSFC employees \u2013 the structure was loaded into the massive vacuum chamber inside Marshall\u2019s X-ray Calibration Facility on August 8, for a four week long test at minus 420 degrees Fahrenheit, testing its flexibility and tolerance margins.<\/font><\/p>\n
<\/font>The Northrop Grumman Corporation is the contractor for the telescope, which \u2013 it is hoped \u2013 will provide new insight into the origins of the universe, looking back more than 10 billion years at the so-called \u2018cosmic dark zone,\u2019 the period when the very first matter likely converged to form stars and galaxies.<\/p>\n
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