{"id":35356,"date":"2018-10-31T16:43:34","date_gmt":"2018-10-31T11:13:34","guid":{"rendered":"https:\/\/blog.forumias.com\/?p=35356"},"modified":"2018-10-31T16:43:34","modified_gmt":"2018-10-31T11:13:34","slug":"as-isro-launch-fails-glitch-in-space-waits-for-fix","status":"publish","type":"post","link":"https:\/\/forumias.com\/blog\/as-isro-launch-fails-glitch-in-space-waits-for-fix\/","title":{"rendered":"As ISRO launch fails, glitch in space waits for fix:\u00a0"},"content":{"rendered":"<p><span style=\"color: #000000;\"><a href=\"http:\/\/indianexpress.com\/article\/explained\/irnss-1h-launch-as-isro-launch-fails-glitch-in-space-waits-for-fix-4823146\/\"><span style=\"font-weight: 400;\">As ISRO launch fails, glitch in space waits for fix<\/span><\/a><span style=\"font-weight: 400;\">:\u00a0<\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><b>Context<\/b><\/span><\/p>\n<ul>\n<li><span style=\"font-weight: 400; color: #000000;\">ISRO declared the IRNSS-1H launch a failure after a heat shield failed to separate, preventing the satellite from being deployed in space by PSLV-C39, the launch vehicle.<\/span><\/li>\n<\/ul>\n<p><span style=\"color: #000000;\"><b>What went wrong?<\/b><\/span><\/p>\n<ul>\n<li><span style=\"font-weight: 400; color: #000000;\">The performance of PSLV-C39 went to plan up to the point when the satellite had to be inserted in orbit.<\/span><\/li>\n<li><span style=\"font-weight: 400; color: #000000;\">During the operation the heat shield did not get separated.<\/span><\/li>\n<\/ul>\n<p><span style=\"color: #000000;\"><b>IRNSS-1H<\/b><\/span><\/p>\n<ul>\n<li><span style=\"font-weight: 400; color: #000000;\">IRNSS-1H was the eighth in a series of IRNSS (Indian Regional Navigation Satellite Systems) satellites to get launched by ISRO since July 2013.<\/span><\/li>\n<li><span style=\"font-weight: 400; color: #000000;\">IRNSS-1H was among nine satellites (seven for the navigation service, two backup) indented at Rs 1,420 crore for IRNSS.<\/span><\/li>\n<\/ul>\n<p><span style=\"color: #000000;\"><b>NavIC<\/b><\/span><\/p>\n<ul>\n<li><span style=\"font-weight: 400; color: #000000;\">It is an Indian navigation satellite constellation, comprising of seven satellites.<\/span><\/li>\n<\/ul>\n<p><span style=\"color: #000000;\"><b>What was IRNSS-1H supposed to do?<\/b><\/span><\/p>\n<ul>\n<li><span style=\"font-weight: 400; color: #000000;\">It was launched to create a constellation to provide satellite-based navigation services over the Indian subcontinent on the lines of the global positioning system (GPS) created by the United States.<\/span><\/li>\n<li><span style=\"font-weight: 400; color: #000000;\">IRNSS-1H was intended to replace IRNSS-1A, which developed problems last year.<\/span><\/li>\n<li><span style=\"font-weight: 400; color: #000000;\">IRNSS-1H would have augmented \u201cthe existing seven satellites of NavIC constellation\u201d.<\/span><\/li>\n<li><span style=\"font-weight: 400; color: #000000;\">It was supposed to sit in a sub-Geosynchronous Transfer Orbit (sub-GTO).<\/span><\/li>\n<\/ul>\n<p><span style=\"color: #000000;\"><b>What kind of problems made a replacement necessary?<\/b><\/span><\/p>\n<ul>\n<li><span style=\"font-weight: 400; color: #000000;\">The first satellite launched on July 1, 2013, had developed problems, rendering the satellite ineffective for navigation services.<\/span><\/li>\n<li><span style=\"font-weight: 400; color: #000000;\">The Three Rubidium Atomic Frequency Standard (RAFS) clocks of IRNSS-1A have stopped working. But the rest of satellite components are functioning perfectly.<\/span><\/li>\n<li><span style=\"font-weight: 400; color: #000000;\">The satellite is still being used for messaging activity.<\/span><\/li>\n<li><span style=\"font-weight: 400; color: #000000;\">There is a talk of launching a replacement site.<\/span><\/li>\n<\/ul>\n<p><span style=\"color: #000000;\"><b>After the failed launch, what can ISRO do?<\/b><\/span><\/p>\n<ul>\n<li><span style=\"font-weight: 400; color: #000000;\">ISRO has one more satellite in its kitty. A new satellite could be launched in the next few months to make up for the loss.<\/span><\/li>\n<\/ul>\n<p><span style=\"color: #000000;\"><b>How do these satellites work?<\/b><\/span><\/p>\n<ul>\n<li><span style=\"font-weight: 400; color: #000000;\">IRNSS intends to provide two services \u2014<\/span><\/li>\n<\/ul>\n<p><span style=\"color: #000000;\"><b>Standard Positioning Service<\/b><span style=\"font-weight: 400;\"> for general users and a Restricted Service, which is an encrypted service only for authorized users like the defence forces.<\/span><\/span><\/p>\n<p><span style=\"color: #000000;\"><b>NavIC<\/b><span style=\"font-weight: 400;\"> is designed to provide accurate position information services to users in India as well as the region, up to 1,500 km from the boundary.<\/span><\/span><\/p>\n<p><span style=\"font-weight: 400; color: #000000;\">For NavIC to become ubiquitous in the subcontinent, ISRO will sell its capabilities to general positioning service providers like mobile phone manufacturers, vehicle manufacturers etc.<\/span><\/p>\n<p><span style=\"color: #000000;\"><b>Couldn\u2019t existing satellite systems have provided such services?<\/b><\/span><\/p>\n<ul>\n<li><span style=\"font-weight: 400; color: #000000;\">One primary reasons for the development of the indigenous Indian system is the reliability that it offers when used for defence purposes.<\/span><\/li>\n<\/ul>\n<p><span style=\"color: #000000;\"><b>What is the payload on IRNSS-1H?<\/b><\/span><\/p>\n<ul>\n<li><span style=\"font-weight: 400; color: #000000;\">IRNSS-1H had both a navigation payload and a ranging payload.<\/span><\/li>\n<li><span style=\"font-weight: 400; color: #000000;\">The ranging payload of IRNSS satellites has a C-band transponder to determine the range of the satellite.<\/span><\/li>\n<li><span style=\"font-weight: 400; color: #000000;\">The navigation payload is meant to transmit navigation service signals to users on earth while operating in the L5-band and S-band. Part of the navigation payload is high-accuracy RAFS clocks.<\/span><\/li>\n<\/ul>\n<p><span style=\"color: #000000;\"><b>Importance of the clocks<\/b><\/span><\/p>\n<ul>\n<li><span style=\"font-weight: 400; color: #000000;\">Atomic clocks act as a key component in a navigation system.<\/span><\/li>\n<li><span style=\"font-weight: 400; color: #000000;\">The ISRO satellites are equipped with three clocks each \u2013 one clock being the primary timekeeper and two acting as backup.<\/span><\/li>\n<li><span style=\"font-weight: 400; color: #000000;\">Accurate timekeeping is important for navigation system as a person\u2019s position on earth is subject to the accurate calculation of delays in signal transmission from the satellite to earth.<\/span><\/li>\n<li><span style=\"font-weight: 400; color: #000000;\">Clocks are so important because if you don\u2019t have the right clocks and even if you don\u2019t consider the relativity theory of Einstein the error would be more than 500 metres in one hour.<\/span><\/li>\n<\/ul>\n<p><span style=\"color: #000000;\"><b>What went wrong with the clocks?<\/b><\/span><\/p>\n<ul>\n<li><span style=\"font-weight: 400; color: #000000;\">The Three RAFS clocks supplied by an European manufacturer, Spectratime, which were used by the ESA for its Galileo satellite navigation system, developed problems.<\/span><\/li>\n<li><span style=\"font-weight: 400; color: #000000;\">These failures seem to have a consistent signature, linked to probable short circuits, and possibly a particular test procedure performed on the ground.<\/span><\/li>\n<\/ul>\n<p><span style=\"color: #000000;\"><b>How has ISRO addressed the problems with the IRNSS clocks?<\/b><\/span><\/p>\n<ul>\n<li><span style=\"font-weight: 400; color: #000000;\">The atomic clocks in new satellites are modified versions of the original clocks provided by Spectratime under a 4-million-euro deal signed in 2008.<\/span><\/li>\n<li><span style=\"font-weight: 400; color: #000000;\">ISRO has been carrying out modifications of clocks acquired from Spectratime to overcome technical issues.<\/span><\/li>\n<\/ul>\n<p><span style=\"color: #000000;\"><b>Who built IRNSS-1H?<\/b><\/span><\/p>\n<ul>\n<li><span style=\"font-weight: 400; color: #000000;\">A consortium led by Alpha Design Technologies, a defence equipment supplier from Bengaluru, built it over eight months.<\/span><\/li>\n<li><span style=\"font-weight: 400; color: #000000;\">The Rs 400-crore company was tasked with making two satellites.<\/span><\/li>\n<li><span style=\"font-weight: 400; color: #000000;\">The second is expected to be complete by April 2018.<\/span><\/li>\n<li><span style=\"font-weight: 400; color: #000000;\">Alpha Designs was backed by a team of 70 ISRO scientists.<\/span><\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>As ISRO launch fails, glitch in space waits for fix:\u00a0 Context ISRO declared the IRNSS-1H launch a failure after a heat shield failed to separate, preventing the satellite from being deployed in space by PSLV-C39, the launch vehicle. What went wrong? The performance of PSLV-C39 went to plan up to the point when the satellite&hellip; <a class=\"more-link\" href=\"https:\/\/forumias.com\/blog\/as-isro-launch-fails-glitch-in-space-waits-for-fix\/\">Continue reading <span class=\"screen-reader-text\">As ISRO launch fails, glitch in space waits for fix:\u00a0<\/span><\/a><\/p>\n","protected":false},"author":61,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"footnotes":""},"categories":[555],"tags":[],"class_list":["post-35356","post","type-post","status-publish","format-standard","hentry","category-test-1","entry"],"jetpack_featured_media_url":"","views":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/posts\/35356","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/users\/61"}],"replies":[{"embeddable":true,"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/comments?post=35356"}],"version-history":[{"count":0,"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/posts\/35356\/revisions"}],"wp:attachment":[{"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/media?parent=35356"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/categories?post=35356"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/tags?post=35356"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}