{"id":2798,"date":"2018-02-27T09:00:17","date_gmt":"2018-02-27T13:00:17","guid":{"rendered":"https:\/\/orbitalhub.com\/?p=2798"},"modified":"2018-02-26T14:32:18","modified_gmt":"2018-02-26T18:32:18","slug":"the-rs-25-engine","status":"publish","type":"post","link":"https:\/\/orbitalhub.com\/?p=2798","title":{"rendered":"The RS-25 Engine"},"content":{"rendered":"<div style=\"float: left; padding-right: 30px;\">\n<p class=\"MsoNormal\" style=\"margin: 5px;\">&nbsp;<\/p>\n<p class=\"MsoNormal\" style=\"margin: 5px;\">\n<iframe loading=\"lazy\" width=\"580\" height=\"326\" src=\"https:\/\/www.youtube.com\/embed\/kJo157o_qaw\" frameborder=\"0\" allow=\"autoplay; encrypted-media\" allowfullscreen><\/iframe>\n<\/p>\n<p class=\"MsoNormal\" style=\"margin: 5px;\">&nbsp;<\/p>\n<p>Wikipedia dixit:<\/p>\n<p>&#8220;The Aerojet Rocketdyne RS-25, otherwise known as the Space Shuttle main engine (SSME), is a liquid-fuel cryogenic rocket engine that was used on NASA&#8217;s Space Shuttle and is planned to be used on its successor, the Space Launch System.<\/p>\n<p>Designed and manufactured in the United States by Rocketdyne (later known as Pratt &#038; Whitney Rocketdyne and Aerojet Rocketdyne), the RS-25 burns cryogenic liquid hydrogen and liquid oxygen propellants, with each engine producing 1,859 kN (418,000 lbf) of thrust at liftoff. Although the RS-25 can trace its heritage back to the 1960s, concerted development of the engine began in the 1970s, with the first flight, STS-1, occurring on April 12, 1981. The RS-25 has undergone several upgrades over its operational history to improve the engine&#8217;s reliability, safety, and maintenance load. Subsequently, the RS-25D is the most efficient liquid fuel rocket engine currently in use.<\/p>\n<p>The engine produces a specific impulse (Isp) of 452 seconds (4.43 km\/s) in a vacuum, or 366 seconds (3.59 km\/s) at sea level, has a mass of approximately 3.5 tonnes (7,700 pounds), and is capable of throttling between 67% and 109% of its rated power level in one-percent increments. The RS-25 operates at temperatures ranging from \u2212253 \u00b0C (\u2212423 \u00b0F) to 3300 \u00b0C (6000 \u00b0F).<\/p>\n<p>The Space Shuttle used a cluster of three RS-25 engines mounted in the stern structure of the orbiter, with fuel being drawn from the external tank. The engines were used for propulsion during the entirety of the spacecraft&#8217;s ascent, with additional thrust being provided by two solid rocket boosters and the orbiter&#8217;s two AJ-10 orbital maneuvering system engines. Following each flight, the RS-25 engines were removed from the orbiter, inspected, and refurbished before being reused on another mission.&#8221;<\/p>\n<p>Video credit: NASA<\/p>\n<p class=\"MsoNormal\" style=\"margin: 5px;\">&nbsp;<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>The Aerojet Rocketdyne RS-25, otherwise known as the Space Shuttle main engine (SSME), is a liquid-fuel cryogenic rocket engine that was used on NASA&#8217;s Space Shuttle and is planned to be used on its successor, the Space Launch System.<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[61,129,1,12,463],"tags":[614],"class_list":["post-2798","post","type-post","status-publish","format-standard","hentry","category-launchers","category-school-aint-over","category-space-exploration","category-spacecraft-design","category-videos","tag-rs-25"],"_links":{"self":[{"href":"https:\/\/orbitalhub.com\/index.php?rest_route=\/wp\/v2\/posts\/2798","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/orbitalhub.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/orbitalhub.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/orbitalhub.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/orbitalhub.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2798"}],"version-history":[{"count":1,"href":"https:\/\/orbitalhub.com\/index.php?rest_route=\/wp\/v2\/posts\/2798\/revisions"}],"predecessor-version":[{"id":2799,"href":"https:\/\/orbitalhub.com\/index.php?rest_route=\/wp\/v2\/posts\/2798\/revisions\/2799"}],"wp:attachment":[{"href":"https:\/\/orbitalhub.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2798"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/orbitalhub.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2798"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/orbitalhub.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2798"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}