{"id":838,"date":"2004-12-02T15:43:00","date_gmt":"2004-12-02T14:43:00","guid":{"rendered":"https:\/\/kids.esa.int\/spaceplanes\/"},"modified":"2026-10-08T00:32:50","modified_gmt":"2026-10-07T22:32:50","slug":"spaceplanes","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fi\/spaceplanes\/","title":{"rendered":"Avaruuslentokoneet"},"content":{"rendered":"
\n

Uudelleenk\u00e4ytett\u00e4vien avaruusalusten laukaisemiseen ja lent\u00e4miseen on useita tapoja.<\/p>\n

Avaruussukkula k\u00e4ytt\u00e4\u00e4 lentoonl\u00e4ht\u00f6\u00f6n omia moottoreitaan sek\u00e4 kahta tehokasta kiinte\u00e4n polttoaineen apurakettia. T\u00e4t\u00e4 kutsutaan toisinaan \u2018yksivaiheiseksi kiertoradalle p\u00e4\u00e4sykseksi\u2019.<\/p>\n<\/div>\n

Yksi avaruussukkulan kaltaisen avaruusaluksen ongelma on polttoaineen ja rakettimoottoreiden aiheuttama lis\u00e4paino. Siit\u00e4 huolimatta sukkulan on palattava Maahan liitimen tavoin. Siin\u00e4 ei ole suihkumoottoreita, eik\u00e4 se voi lent\u00e4\u00e4 ymp\u00e4riins\u00e4 yritt\u00e4\u00e4kseen uudelleen, jos se ohittaa kiitoradan.<\/p>\n

Yksi tapa pienent\u00e4\u00e4 avaruusaluksen kokoa on kuljettaa sit\u00e4 osan matkaa toisen aluksen kyydiss\u00e4. Esimerkiksi suuri lentokone voi kuljettaa avaruuslentokoneen 10 km:n korkeuteen. Kun avaruuslentokone on noussut suurimman osan ilmakeh\u00e4st\u00e4 yl\u00e4puolelle, se irrotetaan.<\/p>\n

Rakettia voidaan k\u00e4ytt\u00e4\u00e4 my\u00f6s uudelleenk\u00e4ytett\u00e4v\u00e4n avaruusaluksen laukaisemiseen. 1990-luvun alkupuolella ESA tutki mahdollisuutta laukaista pieni avaruuslentokone nimelt\u00e4 Hermes Ariane-5-kantoraketin k\u00e4rjess\u00e4.<\/p>\n

Toinen tapa kevent\u00e4\u00e4 painoa voisi olla uuden sukupolven moottoreiden k\u00e4ytt\u00f6, jotka hy\u00f6dynt\u00e4v\u00e4t ilmakeh\u00e4n ilmaa nousun alkuvaiheessa. Vasta kun alus saavuttaa avaruuden, se siirtyisi k\u00e4ytt\u00e4m\u00e4\u00e4n rakettivoimaa, jossa hy\u00f6dynnet\u00e4\u00e4n aluksella olevaa happea. T\u00e4llaiset moottorit ovat kuitenkin viel\u00e4 monien vuosien p\u00e4\u00e4ss\u00e4.<\/p>","protected":false},"excerpt":{"rendered":"

There are various ways to launch and fly reusable spacecraft. The Space Shuttle uses its own engines, together with two powerful solid rocket boosters, to get off the ground. This […]<\/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\/future_launchers5\/18249547-2-eng-GB\/Future_launchers.jpg","esa_banner_description":"","esa_banner_credit":"ESA-C. VIJOUX","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2004\/12\/Future_launchers5","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":[10,41,40],"tags":[2],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-838","post","type-post","status-publish","format-standard","hentry","category-learn","category-rockets-technology","category-technology","tag-background-article"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/838","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/comments?post=838"}],"version-history":[{"count":1,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/838\/revisions"}],"predecessor-version":[{"id":1981,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/838\/revisions\/1981"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/media?parent=838"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/categories?post=838"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/tags?post=838"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/panel?post=838"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/language?post=838"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/age?post=838"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/duration?post=838"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/resource_type?post=838"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/audience?post=838"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/wf_post_folders?post=838"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}