{"id":26,"date":"2012-11-13T18:44:40","date_gmt":"2012-11-13T18:44:40","guid":{"rendered":"http:\/\/sophia.estec.esa.int\/gtoc_portal\/?page_id=26"},"modified":"2020-01-09T15:26:04","modified_gmt":"2020-01-09T14:26:04","slug":"gtoc-6","status":"publish","type":"page","link":"https:\/\/sophia.estec.esa.int\/gtoc_portal\/?page_id=26","title":{"rendered":"GTOC 6 &#8211; Global mapping of galilean moons"},"content":{"rendered":"<p><a href=\"http:\/\/sophia.estec.esa.int\/gtoc_portal\/wp-content\/uploads\/2012\/12\/jpl_logo.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignright  wp-image-462\" title=\"jpl_logo\" src=\"http:\/\/sophia.estec.esa.int\/gtoc_portal\/wp-content\/uploads\/2012\/12\/jpl_logo-300x187.jpg\" alt=\"\" width=\"100\" height=\"84\" \/><\/a>This edition was organised by Anastassios Petropoulos of the Jet Propulsion Laboratory Outer Planets Mission Analysis Group. The problem statement was released to the community on the 10th September 2012.<\/p>\n<h5>In a nutshell<\/h5>\n<p>The four Galilean moons of jupiter (Io, Europa, Ganymede and Callisto) have to be mapped globally using repeated multiple fly-bys of a low-thrust\u00a0spacecraft\u00a0 Each fly-by pericenter vector defines the visited point on the moon surface that is considered as divided into 32 faces in a similar manner as soccer balls. The objective function rewards the number of different faces visited as well as faces that are more difficult to visit \u00a0with added bonus for Europa that has a higher scientific interest.<\/p>\n<ul>\n<li><a href=\"http:\/\/sophia.estec.esa.int\/gtoc_portal\/wp-content\/uploads\/2020\/01\/gtoc6_team_list.txt\">List of registered teams<\/a><\/li>\n<li><a href=\"http:\/\/sophia.estec.esa.int\/gtoc_portal\/wp-content\/uploads\/2012\/11\/gtoc6_problem_stmt-2.pdf\">Problem statement<\/a><\/li>\n<li>Output file format &#8211;\u00a0<a href=\"http:\/\/sophia.estec.esa.int\/gtoc_portal\/wp-content\/uploads\/2012\/11\/gtoc6_traj_format.txt\">trajectory<\/a>, <a href=\"http:\/\/sophia.estec.esa.int\/gtoc_portal\/wp-content\/uploads\/2012\/11\/gtoc6_flyby_format.txt\">fly-by<\/a>, <a href=\"http:\/\/sophia.estec.esa.int\/gtoc_portal\/wp-content\/uploads\/2012\/11\/gtoc6_perijove_format.txt\">perijove<\/a><\/li>\n<li><a href=\"http:\/\/sophia.estec.esa.int\/gtoc_portal\/wp-content\/uploads\/2012\/11\/ACT-RPT-MAD-GTOC6-ranks.pdf\">Final rankings<\/a><\/li>\n<\/ul>\n<h5>The Winners<\/h5>\n<p>Led by Lorenzo Casalino and\u00a0Guido Colasurdo, the team from Turin Polytechnic and &#8220;Sapienza&#8221; University of Rome won this edition with a trajectory mapping partially Callisto first, then all Ganymede, then all Europa and then all Io.<\/p>\n<h5>Curiosities<\/h5>\n<p>Considered as the most difficult of all GTOC\u00a0problems\u00a0released so far, the original plan from the\u00a0organiser\u00a0was even more ambitious having the spacecraft depart from the Earth rather than from Jupiter sphere of influence.<\/p>\n<p>The second ranked trajectory, found by a team from the European Space Agency, used an entirely different strategy switching moon very frequently rather than mapping a moon at a time, and yet reached a very similar objective value.<\/p>\n<p>It is debated\u00a0whether\u00a0the theoretical maximim score of 324 can be reached.<\/p>\n<p>In 2012 (December), shortly\u00a0after\u00a0the competition ended, a solution scoring 316\/324 was found by the\u00a0team from the European Space Agency\u00a0(and validated by Anastassios Petropoulos from JPL). The Paper (<a href=\"http:\/\/sophia.estec.esa.int\/gtoc_portal\/wp-content\/uploads\/2012\/11\/gtoc6_316.pdf\">pdf link<\/a>)\u00a0was accepted in the GECCO 2013 conference in Amsterdam and won the Gold <a href=\"http:\/\/www.genetic-programming.org\/hc2005\/main.html\">Humies<\/a> award, a prestigious recognition given to human competitive results found using evolutionary techniques.<\/p>\n<p>In 2014 (August)\u00a0<span style=\"color: #222222;\">Yang Gao from the\u00a0<\/span><span style=\"color: #222222;\">Technology and Engineering Center for Space Utilization, Chinese Academy of Sciences <a href=\"https:\/\/groups.google.com\/forum\/#!topic\/gtoc_competition\/2a1oZRSak0I\">announced to have reached a 320\/324 score<\/a>.<\/span><\/p>\n<p>The problem is quite relevant to the <a href=\"http:\/\/opfm.jpl.nasa.gov\/europajupitersystemmissionejsm\/jupitereuropaorbiterconcept\/\">JEO concept<\/a>\u00a0(NASA element of the joint <a href=\"http:\/\/opfm.jpl.nasa.gov\/files\/EJSM%20Summary%20Report%20Final%20for%20Print_090120_rk.pdf\">NASA\/ESA EJSM<\/a> mission) in showing the use of fly-bys rather than orbiters to perform the moon full mapping.<\/p>\n<p>The trajectory from the team from CU Boulder is visualized below.<\/p>\n<p><iframe loading=\"lazy\" title=\"GTOC 6 - CU Boulder - Jupiter moon tour\" width=\"660\" height=\"495\" src=\"https:\/\/www.youtube.com\/embed\/wSS2HroC2ww?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","protected":false},"excerpt":{"rendered":"<p>This edition was organised by Anastassios Petropoulos of the Jet Propulsion Laboratory Outer Planets Mission Analysis Group. The problem statement was released to the community on the 10th September 2012. In a nutshell The four Galilean moons of jupiter (Io, Europa, Ganymede and Callisto) have to be mapped globally using repeated multiple fly-bys of a &hellip; <a href=\"https:\/\/sophia.estec.esa.int\/gtoc_portal\/?page_id=26\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">GTOC 6 &#8211; Global mapping of galilean moons<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"open","template":"","meta":{"footnotes":""},"class_list":["post-26","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/sophia.estec.esa.int\/gtoc_portal\/index.php?rest_route=\/wp\/v2\/pages\/26","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sophia.estec.esa.int\/gtoc_portal\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sophia.estec.esa.int\/gtoc_portal\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sophia.estec.esa.int\/gtoc_portal\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sophia.estec.esa.int\/gtoc_portal\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=26"}],"version-history":[{"count":27,"href":"https:\/\/sophia.estec.esa.int\/gtoc_portal\/index.php?rest_route=\/wp\/v2\/pages\/26\/revisions"}],"predecessor-version":[{"id":1034,"href":"https:\/\/sophia.estec.esa.int\/gtoc_portal\/index.php?rest_route=\/wp\/v2\/pages\/26\/revisions\/1034"}],"wp:attachment":[{"href":"https:\/\/sophia.estec.esa.int\/gtoc_portal\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=26"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}