{"id":38089,"date":"2019-03-26T20:15:09","date_gmt":"2019-03-26T12:15:09","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/spacex-proves-higher-than-necessary-safety-of-starlink-constellation\/"},"modified":"2019-03-26T20:15:09","modified_gmt":"2019-03-26T12:15:09","slug":"spacex-proves-higher-than-necessary-safety-of-starlink-constellation","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/spacex-proves-higher-than-necessary-safety-of-starlink-constellation\/","title":{"rendered":"SpaceX proves higher than necessary safety of Starlink constellation"},"content":{"rendered":"<p>In an electronic filing with the Federal Communications Commission (FCC), SpaceX has demonstrated a higher than necessary safety for their Starlink constellation satellites in terms of collision risk with other objects in orbit in the scenario that a Starlink satellite becomes uncontrollable after launch.<\/p>\n<p>The filing, in response to FCC questions, reveals SpaceX\u2019s upcoming space-based internet project carries a collision risk 2.1 times less likely than the accepted NASA standard. <\/p>\n<p>The filing occurred on 13 March 2019 in response to a series of FCC follow-up questions from previous approvals and relates to SpaceX\u2019s upcoming deployment of the first batch of Starlink satellites into an initial operational orbit of 550 km.<\/p>\n<p>The first Starlinks are expected to launch No Earlier Than (NET) May from Florida aboard one of SpaceX\u2019s Falcon 9 rockets.<\/p>\n<p>Initially, the Starlink constellation was to comprise 12,000 satellites in two operational rings. However, SpaceX now plans three operational rings located at altitudes of 350 km, 550 km, and 1,200 km.<\/p>\n<p>The first two demo Starlink satellites,&nbsp;Tintin A and Tintin B, were launched on a Falcon 9 in February 2018 from Vandenberg Air Force Base, CA, as a ride-along payload to the Paz satellite.<\/p>\n<\/p>\n<p><iframe title=\"Spacex First two Starlink global Internet demo satellites deployed\" src=\"https:\/\/www.youtube.com\/embed\/P9r0rSPT4ns?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" allowfullscreen=\"\" name=\"fitvid0\" data-gtm-yt-inspected-14=\"true\" data-gtm-yt-inspected-21=\"true\"><\/iframe><\/p>\n<p>The 550 km orbital ring was an addition first confirmed by FCC filings in November 2018. &nbsp;Because this orbital altitude is above numerous Low Earth Orbit satellites and outposts, most notably the International Space Station, the FCC requested updated information on collision risks should one of the 1,584 satellites in the 550 km orbital ring become disabled immediately after orbital insertion.<\/p>\n<p>Rocket building kits<path d=\"M7.59009 18.59L9.00009 20L17.0001 12L9.00009 4L7.59009 5.41L14.1701 12\" style=\"animation: initial !important; background: initial !important; border: 0px !important; box-shadow: none !important; color: inherit !important; cursor: inherit !important; direction: inherit !important; display: inline !important; fill: currentcolor !important; filter: initial !important; float: none !important; margin: 0px !important; opacity: initial !important; outline: 0px !important; overflow: initial !important; padding: 0px !important; stroke: initial !important; transform: initial !important; vertical-align: initial !important; visibility: inherit !important;\"><\/path>Space Shuttle models<path d=\"M7.59009 18.59L9.00009 20L17.0001 12L9.00009 4L7.59009 5.41L14.1701 12\" style=\"animation: initial !important; background: initial !important; border: 0px !important; box-shadow: none !important; color: inherit !important; cursor: inherit !important; direction: inherit !important; display: inline !important; fill: currentcolor !important; filter: initial !important; float: none !important; margin: 0px !important; opacity: initial !important; outline: 0px !important; overflow: initial !important; padding: 0px !important; stroke: initial !important; transform: initial !important; vertical-align: initial !important; visibility: inherit !important;\"><\/path>Spaceflight history books<path d=\"M7.59009 18.59L9.00009 20L17.0001 12L9.00009 4L7.59009 5.41L14.1701 12\" style=\"animation: initial !important; background: initial !important; border: 0px !important; box-shadow: none !important; color: inherit !important; cursor: inherit !important; direction: inherit !important; display: inline !important; fill: currentcolor !important; filter: initial !important; float: none !important; margin: 0px !important; opacity: initial !important; outline: 0px !important; overflow: initial !important; padding: 0px !important; stroke: initial !important; transform: initial !important; vertical-align: initial !important; visibility: inherit !important;\"><\/path>\n<p>     (adsbygoogle = window.adsbygoogle || []).push({});<\/p>\n<h4 class=\"widget-title penci-border-arrow\">See Also<\/h4>\n<ul>\n<li>Falcon 9\/DM-1 UPDATES<\/li>\n<li>SpaceX General Section<\/li>\n<li>L2 SpaceX Section<\/li>\n<li>Click here to Join L2<\/li>\n<\/ul>\n<p>In response, SpaceX provided data demonstrating the statistical unlikelihood of a Starlink satellite being a collision risk or colliding with another object in orbit should it suffer a complete propulsion system failure rendering it incapable of collision-avoidance immediately after separation from the Falcon 9.<\/p>\n<p>\u201cDue to SpaceX\u2019s decision to minimize risk by using the low injection altitude of 350 km, in the unlikely event any satellites after the initial launch experience immediate failure upon deployment, they would decay to the point of demise very quickly \u2013 as little as two weeks to at most eight months depending on the solar cycle,\u201d states the FCC filing.<\/p>\n<p>After initial injection into a 350 km orbit, the 1,584 Starlinks of the 550 km operational ring will use their Hall-effect thrusters to raise their orbits.<\/p>\n<p>Per the documents submitted, SpaceX showed the collision risk of a single uncontrollable Starlink satellite in its stowed configuration in the 550 km ring was 0.000000303 at solar minimum and 0.000000114 at solar maximum.<\/p>\n<p><img fetchpriority=\"high\" decoding=\"async\" aria-describedby=\"caption-attachment-60757\" class=\"size-full wp-image-60757\" src=\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/Screen-Shot-2019-03-26-at-11.26.40.png\" alt=\"\" width=\"1346\" height=\"418\" srcset=\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/Screen-Shot-2019-03-26-at-11.26.40.png 1346w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/Screen-Shot-2019-03-26-at-11.26.40-350x109.png 350w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/Screen-Shot-2019-03-26-at-11.26.40-630x196.png 630w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/Screen-Shot-2019-03-26-at-11.26.40-768x239.png 768w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/Screen-Shot-2019-03-26-at-11.26.40-1170x363.png 1170w\" sizes=\"(max-width: 1346px) 100vw, 1346px\"><\/p>\n<p id=\"caption-attachment-60757\" class=\"wp-caption-text\">Table showing the single-Starlink collision risk at solar minimum and solar maximum in both stowed and deployed configuration . (SpaceX FCC submission)<\/p>\n<p>In a deployed configuration, the solar minimum risk decreases to 0.000000274 and the solar maximum risk rises slightly to 0.000000137.<\/p>\n<p>So what do those individual Starlink collision risk calculations mean compared to the safety standard the FCC generally accepts?<\/p>\n<p>The \u201cprevailing NASA safety standard\u201d is calculated at 0.001 per satellite in terms of risk of collision after the irrecoverable failure of a propulsion system.<\/p>\n<p>Thus, a single uncontrollable Starlink satellite\u2019s collision risk is less likely by several thousand magnitudes compared to the accepted NASA standard.<\/p>\n<p>Moreover, \u201ceven assuming a highly unlikely and apocryphal case in which all 1,584 satellites proposed for deployment at 550 kilometers were immediately incapable of maneuvering upon orbital injection, remained in a stowed configuration, and were deorbiting during a period of solar minimum, the aggregate probability of collision would be 1,584 x 0.000000303 = 0.00048 \u2013 which is still less than half the 0.001 probability standard established by NASA.\u201d\n<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" aria-describedby=\"caption-attachment-60761\" class=\"size-full wp-image-60761\" src=\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/2019-03-26-164630.jpg\" alt=\"\" width=\"1277\" height=\"686\" srcset=\"https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/2019-03-26-164630.jpg 1277w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/2019-03-26-164630-350x188.jpg 350w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/2019-03-26-164630-630x338.jpg 630w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/2019-03-26-164630-768x413.jpg 768w, https:\/\/www.nasaspaceflight.com\/wp-content\/uploads\/2019\/03\/2019-03-26-164630-1170x629.jpg 1170w\" sizes=\"(max-width: 1277px) 100vw, 1277px\"><\/p>\n<p id=\"caption-attachment-60761\" class=\"wp-caption-text\">The Starlink Demo sats heading to space on the PAZ mission \u2013 SpaceX<\/p>\n<p>In other words, 1,584 of SpaceX\u2019s Starlink satellites together carry 2.1 times less of a collision risk than the single-satellite standard of safety as defined by NASA and used by the FCC for safety assessment.<\/p>\n<p>Moreover, it is basically impossible for all of the 1,584 Starlink satellites to be deployed in a 550 km orbit to suffer complete system failures as that amount of satellites will not be deployed at a single time.<\/p>\n<p>Additionally, should an entire deployment batch of Starlinks suffer a failure, SpaceX would halt future launches until the issue had been resolved.<\/p>\n<p><b>Second generation Starlinks to be completely \u201cdemisable\u201d:<\/b><\/p>\n<p>Following discussion of collision risk, the FCC also had follow-up questions regarding the risk to land, sea, and air during a Starlink satellite deorbit and atmospheric reentry.<\/p>\n<p>The answers provided confirm that the first generation of Starlink satellites, fewer than 75, will include iron thrusters and steel reaction wheels on all satellites, components that would likely survive atmospheric reentry and make it to the ground or ocean.<\/p>\n<\/p>\n<p><iframe title=\"Starlink revisions, Nov 2018\" src=\"https:\/\/www.youtube.com\/embed\/QEIUdMiColU?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" allowfullscreen=\"\" name=\"fitvid1\" data-gtm-yt-inspected-14=\"true\" data-gtm-yt-inspected-21=\"true\"><\/iframe><\/p>\n<p>This in itself is not an issue as numerous satellites and vehicles launched into orbit contain components that can survive atmospheric reentry even without a heat shield.<\/p>\n<p>In Starlink\u2019s case, the FCC filing confirms that after the 75 first generation satellites, subsequent generations of Starlink satellites will use components that are completely \u201cdemisable\u201d, that is the entire satellite will completely burn up in Earth\u2019s atmosphere during reentry with no component surviving to the ground or ocean.<\/p>\n<p>\u201cSpaceX\u2019s drive towards complete demisability has led to great strides across the spacecraft such that SpaceX now plans for a fully demisable spacecraft after the initial design version,\u201d notes the FCC filing.<\/p>\n<p>This type of design completely eliminates potential hazards to people on the ground and reinforces SpaceX\u2019s commitment to leave as small a footprint as possible and make the Starlink constellation as safe as possible.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>In an electronic filing with the Federal Communications Commission (FCC), SpaceX has demonstrated a higher than necessary safety for their Starlink constellation satellites in terms of collision risk with other objects in orbit in the scenario that a Starlink satellite becomes uncontrollable after launch. The filing, in response to FCC questions, reveals SpaceX\u2019s upcoming space-based [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":28086,"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":[316,440],"class_list":["post-38089","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news","tag-spacex","tag-starlink"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/38089"}],"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=38089"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/38089\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media\/28086"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=38089"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=38089"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=38089"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}