{"id":14013,"date":"2015-04-16T13:14:43","date_gmt":"2015-04-16T20:14:43","guid":{"rendered":"http:\/\/lifeboat.com\/blog\/?p=14013"},"modified":"2015-04-20T18:08:27","modified_gmt":"2015-04-21T01:08:27","slug":"spacexs-success","status":"publish","type":"post","link":"https:\/\/lifeboat.com\/blog\/2015\/04\/spacexs-success","title":{"rendered":"SpaceX\u2019s Success"},"content":{"rendered":"<p>I read all the news about SpaceX\u2019s Falcon 9 latest \u201cfailure\u201d to land on an autonomous spaceport drone ship aka barge. I view these as trials to success. Here\u2019s why.<\/p>\n<p><strong>1. Grasshopper Successes:<\/strong> The two videos below show that the early landing trials aka Grasshopper from several heights between 250m and 1,000m.<\/p>\n<p>The lessons here are:<\/p>\n<p>a) Pinpoint landing of a 1st stage rocket is technologically feasible.<\/p>\n<p>b) This 1st stage rocket has to attain zero vertical velocity at a minimum 250m above the barge.<\/p>\n<p>Video of 250m test<\/p>\n<p><iframe loading=\"lazy\" title=\"Grasshopper 24-Story Hover Slam 3\/7\/13 | Multi-Angle\" width=\"640\" height=\"360\" src=\"https:\/\/www.youtube.com\/embed\/orUjSkc2pG0?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<p>Video of 1,000m test<\/p>\n<p><iframe loading=\"lazy\" title=\"SpaceX Grasshopper Jumps Over 1000 Feet - Hexacopter Video\" width=\"640\" height=\"360\" src=\"https:\/\/www.youtube.com\/embed\/o35YE8SUroM?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<p><strong>2. Falcon 9 1st stage crash landing \u2014 1st attempt:<\/strong> SpaceX tells us that the failure was due to a hard landing (see video below) but at 0:03 minutes into the video one can see that the 1st stage has substantially tilted before it hit the deck i.e. the 1st stage did not tilt because it hit the deck.<\/p>\n<p>The lessons here:<\/p>\n<p>a) A wobble \u2014 a dynamic instability \u2014 occurs before landing.<\/p>\n<p>b) The guidance systems are unable to cope with new wobble.<\/p>\n<p>Video of 1st attempt<\/p>\n<p><iframe loading=\"lazy\" title=\"Raw: SpaceX Releases Video of Crash Landing\" width=\"640\" height=\"360\" src=\"https:\/\/www.youtube.com\/embed\/YyZIuFXCswo?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<p><strong>3. Falcon 9 1st stage crash landing \u2014 2nd attempt:<\/strong> The video of the second attempt (below) confirms that indeed a wobble has been introduced before the stabilization fins are deployed. Further, this deployment exacerbates the wobble, and the guidance systems is unable to handle this exacerbated wobble.<\/p>\n<p>The lessons here:<\/p>\n<p>a) 1st stage vertical velocity needs to be zero by at least 250m above deck.<\/p>\n<p>b) The stabilization fins need to be redesigned to alleviate exacerbation.<\/p>\n<p>c) Like the Space Ship One\u2019s shuttlecock approach, the 1st stage upper fins need to be deployed before the lower fins are.<\/p>\n<p>d) Upgrade the landing guidance system to account for more severe wobbles.<\/p>\n<p><iframe loading=\"lazy\" title=\"Raw Video: SpaceX Falcon 9 Rocket Fails to Land on Barge\" width=\"640\" height=\"360\" src=\"https:\/\/www.youtube.com\/embed\/GbYQQE5LZ2E?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<p>If at a minimum, SpaceX achieves zero velocity at 250m before deployment of landing gear it will be successful. The other recommendations are good to have.<\/p>\n<p>I expect SpaceX to be successful by their 3rd try.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I read all the news about SpaceX\u2019s Falcon 9 latest \u201cfailure\u201d to land on an autonomous spaceport drone ship aka barge. I view these as trials to success. Here\u2019s why. 1. Grasshopper Successes: The two videos below show that the early landing trials aka Grasshopper from several heights between 250m and 1,000m. The lessons here [\u2026]<\/p>\n","protected":false},"author":224,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[40,1528,38,1522,8,1514],"tags":[1808,735,1809,1810,457],"class_list":["post-14013","post","type-post","status-publish","format-standard","hentry","category-complex-systems","category-disruptive-technology","category-engineering","category-innovation","category-space","category-space-travel","tag-1st-stage-crash-landing","tag-elon-musk","tag-falcon-9","tag-grasshopper","tag-spacex"],"_links":{"self":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/14013","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/users\/224"}],"replies":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/comments?post=14013"}],"version-history":[{"count":0,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/14013\/revisions"}],"wp:attachment":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/media?parent=14013"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/categories?post=14013"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/tags?post=14013"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}