{"id":823,"date":"2004-12-09T15:52:00","date_gmt":"2004-12-09T14:52:00","guid":{"rendered":"https:\/\/kids.esa.int\/space_velocity\/"},"modified":"2026-10-08T00:32:41","modified_gmt":"2026-10-07T22:32:41","slug":"space_velocity","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/da\/space_velocity\/","title":{"rendered":"Rumhastighed"},"content":{"rendered":"
\n

Objekter, der bev\u00e6ger sig rundt om en planet, kaldes satellitter. Hver gang en satellit fuldf\u00f8rer en oml\u00f8bsbane rundt om planeten, kaldes det en bane.<\/p>\n<\/div>\n

Jorden har \u00e9n naturlig satellit \u2013 M\u00e5nen. Men siden oktober 1957 er der blevet sendt mange tusinde kunstige (menneskeskabte) satellitter i kredsl\u00f8b omkring Jorden.<\/p>\n

For at forblive i kredsl\u00f8b skal en satellit bev\u00e6ge sig med en meget h\u00f8j hastighed, som afh\u00e6nger af h\u00f8jden. For et cirkul\u00e6rt kredsl\u00f8b i en h\u00f8jde p\u00e5 300 km over Jordens overflade kr\u00e6ves der s\u00e5ledes typisk en hastighed p\u00e5 7,8 km\/s (28.000 km\/t). Ved denne hastighed vil satellitten fuldf\u00f8re en oml\u00f8bsbane omkring Jorden p\u00e5 90 minutter.<\/p>\n

Satellitter er n\u00f8dt til at bev\u00e6ge sig s\u00e5 hurtigt for at modvirke Jordens tyngdekraft. Det kan sammenlignes med, n\u00e5r man kaster en cricket- eller baseball. Jo h\u00e5rdere bolden kastes, desto l\u00e6ngere flyver den, f\u00f8r den rammer jorden.<\/p>\n

Hvis en spiller kunne kaste bolden h\u00e5rdt nok til, at den n\u00e5ede den n\u00f8dvendige hastighed, ville bolden g\u00e5 i kredsl\u00f8b. Den ville aldrig falde tilbage til Jorden. Kaster man den endnu h\u00e5rdere, s\u00e5 den n\u00e5r en hastighed p\u00e5 11,2 km\/s (40.300 km\/h) \u2013 ogs\u00e5 kaldet \u2018flugthastighed\u2019 \u2013 vil bolden forlade Jorden helt. Den vil derefter blive en \u2018satellit\u2019 omkring Solen.<\/p>","protected":false},"excerpt":{"rendered":"

Objects that travel around a planet are called satellites. Each complete journey a satellite makes around the planet is called an orbit. Our Earth has one natural satellite \u2013 the […]<\/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\/2004\/12\/newton_s_cannon2\/17886950-2-eng-GB\/Newton_s_cannon.gif","esa_banner_description":"","esa_banner_credit":"ESA","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2004\/12\/Newton_s_cannon2","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-823","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\/823","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=823"}],"version-history":[{"count":1,"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/posts\/823\/revisions"}],"predecessor-version":[{"id":1966,"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/posts\/823\/revisions\/1966"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/media?parent=823"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/categories?post=823"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/tags?post=823"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/panel?post=823"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/language?post=823"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/age?post=823"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/duration?post=823"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/resource_type?post=823"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/audience?post=823"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/da\/wp-json\/wp\/v2\/wf_post_folders?post=823"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}