{"id":820,"date":"2004-12-02T15:35:00","date_gmt":"2004-12-02T14:35:00","guid":{"rendered":"https:\/\/kids.esa.int\/gravity_assists\/"},"modified":"2026-10-08T00:32:39","modified_gmt":"2026-10-07T22:32:39","slug":"gravity_assists","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/da\/gravity_assists\/","title":{"rendered":"Tyngdekraftsassistance"},"content":{"rendered":"
\n

Som du ved, har en bil en tendens til at s\u00e6nke farten, n\u00e5r den k\u00f8rer op ad et bjerg, og til at accelerere, n\u00e5r den k\u00f8rer ned ad bakke. Man kan sige, at bilen f\u00e5r en \u2018tyngdekraftshj\u00e6lp\u2019, da Jordens tyngdekraft hj\u00e6lper den med at s\u00e6nke farten eller accelerere. P\u00e5 samme m\u00e5de er det muligt for et rumfart\u00f8j at f\u00e5 en gratis tur uden at bruge v\u00e6rdifuldt br\u00e6ndstof.<\/p>\n<\/div>\n

Tyngdekraftsman\u00f8vrer finder sted, n\u00e5r et rumfart\u00f8j flyver forbi en planet eller en stor m\u00e5ne. Dette g\u00f8r det muligt for planetens tyngdekraft at p\u00e5virke rumfart\u00f8jet og \u00e6ndre dets bane.<\/p>\n

Nogle gange \u00f8ger rumfart\u00f8jet farten, andre gange s\u00e6nker det farten \u2013 alt efter, om det passerer bagved eller foran planeten. Tyngdekraftsman\u00f8vren \u00e6ndrer ogs\u00e5 den retning, rumfart\u00f8jet bev\u00e6ger sig i.<\/p>\n

En af de mest fantastiske tyngdekraftsman\u00f8vrer blev anvendt i forbindelse med ESA\u2019s Ulysses-mission. Ved at passere over Jupiters nordpol blev Ulysses slynget ind i en bane, der f\u00f8rte den forbi Solens poler.<\/p>\n

Cassini-Huygens-missionen benyttede sig af fire tyngdekraftsman\u00f8vrer (\u00e9n med Jorden, to med Venus og \u00e9n med Jupiter) p\u00e5 sin rejse mod Saturn.<\/p>\n

Tyngdekraften spillede ogs\u00e5 en rolle i ESA\u2019s SMART-1-mission. Efter at have bev\u00e6get sig v\u00e6k fra Jorden i en spiralbane i 14 m\u00e5neder begyndte rumfart\u00f8jet at m\u00e6rke M\u00e5nens tiltr\u00e6kning. I november 2004 blev SMART-1 fanget af M\u00e5nens tyngdekraft og gik ind i en bane omkring den.<\/p>","protected":false},"excerpt":{"rendered":"

As you know, a car tends to slow down when it goes up a mountain and to accelerate when it is going downhill. One can say that the car is […]<\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"esa_banner_image":"https:\/\/www.esa.int\/var\/esa\/storage\/images\/esa_multimedia\/images\/2003\/08\/ulysses_and_the_heliosphere2\/17889541-2-eng-GB\/Ulysses_and_the_heliosphere.jpg","esa_banner_description":"Ulysses and the heliosphere","esa_banner_credit":"ESA (image by D. Hardy)","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2003\/08\/Ulysses_and_the_heliosphere2","esa_external_url":"","esa_external_new_window":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":true},"categories":[10,65,40],"tags":[2],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-820","post","type-post","status-publish","format-standard","hentry","category-learn","category-mission-control","category-technology","tag-background-article"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/posts\/820","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/comments?post=820"}],"version-history":[{"count":1,"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/posts\/820\/revisions"}],"predecessor-version":[{"id":1963,"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/posts\/820\/revisions\/1963"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/media?parent=820"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/categories?post=820"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/tags?post=820"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/panel?post=820"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/language?post=820"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/age?post=820"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/duration?post=820"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/resource_type?post=820"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/audience?post=820"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/wf_post_folders?post=820"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}