{"id":1453,"date":"2013-04-25T10:17:17","date_gmt":"2013-04-25T14:17:17","guid":{"rendered":"http:\/\/www.graymanwrites.com\/blog\/?p=1453"},"modified":"2013-04-25T10:17:17","modified_gmt":"2013-04-25T14:17:17","slug":"soft-x-rays-and-data-relay","status":"publish","type":"post","link":"https:\/\/www.grayrinehart.com\/blog\/soft-x-rays-and-data-relay\/","title":{"rendered":"Soft X-Rays and a Data Relay"},"content":{"rendered":"

Twenty years ago today — April 25, 1993 — the first satellite completely sponsored by the Department of Energy launched on a Pegasus booster, dropped from the wing of NASA’s B-52.<\/p>\n

\"\"
\n(ALEXIS satellite artist’s conception. NASA image from Wikimedia Commons.)<\/em><\/p>\n

The Array of Low Energy X-Ray Imaging Sensors (ALEXIS)<\/a> satellite’s primary instrument was an X-ray telescope array tuned to “ultrasoft” X-rays for making a sky map in that part of the electromagnetic spectrum, as well as the “Blackbeard” VHF receiver “for studying the effect of lightning and electromagnetic impulse from exploding [nuclear] devices on the ionospheric transmission.”<\/p>\n

During its flight, one of the satellite’s solar array paddles was damaged, and controllers could not establish contact with the spacecraft for 3 months. Once they established contact, they had to develop specific attitude control procedures to bring the satellite under control, after which the spacecraft performed well although “the astronomy data needed a full pointing and aspect solution in order to be interpreted.”<\/p>\n

And, to complete the promise implied by the title of this post:\u00a05 years ago today — April 25, 2008 — China launched its first data-relay satellite, Tianlian 1<\/a>, on a Long March 3C rocket from Xichang Launch Center.<\/p>\n\"Facebook\"<\/a>\"twitter\"<\/a>\"pinterest\"<\/a>\"linkedin\"<\/a>\"mail\"<\/a>by <\/span>\"feather\"<\/a>","protected":false},"excerpt":{"rendered":"

Twenty years ago today — April 25, 1993 — the first satellite completely sponsored by the Department of Energy launched on a Pegasus booster, dropped from the wing of NASA’s B-52. (ALEXIS satellite artist’s conception. NASA image from Wikimedia Commons.) The Array of Low Energy X-Ray Imaging Sensors (ALEXIS) satellite’s \u2026 Continue reading → <\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[26,141,11],"class_list":["post-1453","post","type-post","status-publish","format-standard","hentry","category-space","tag-launch","tag-pegasus","tag-space-history"],"_links":{"self":[{"href":"https:\/\/www.grayrinehart.com\/blog\/wp-json\/wp\/v2\/posts\/1453","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.grayrinehart.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.grayrinehart.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.grayrinehart.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.grayrinehart.com\/blog\/wp-json\/wp\/v2\/comments?post=1453"}],"version-history":[{"count":1,"href":"https:\/\/www.grayrinehart.com\/blog\/wp-json\/wp\/v2\/posts\/1453\/revisions"}],"predecessor-version":[{"id":1454,"href":"https:\/\/www.grayrinehart.com\/blog\/wp-json\/wp\/v2\/posts\/1453\/revisions\/1454"}],"wp:attachment":[{"href":"https:\/\/www.grayrinehart.com\/blog\/wp-json\/wp\/v2\/media?parent=1453"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.grayrinehart.com\/blog\/wp-json\/wp\/v2\/categories?post=1453"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.grayrinehart.com\/blog\/wp-json\/wp\/v2\/tags?post=1453"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}