CINXE.COM
NASA - Space Shuttle Main Engines
<!DOCTYPE "xmlns:xsl='http://www.w3.org/1999/XSL/Transform'"><!--Get Meta Data starts--><!--Get Meta Data ends--><html xmlns:java_code="xalan://gov.nasa.build.Utils2"><head><META http-equiv="Content-Type" content="text/html; charset=UTF-8"><!--Meta Data starts--><!--SYSTEM DEFINED METADATA--><META content="IE=7" http-equiv="X-UA-Compatible"><META NAME="CMS Document Id" CONTENT="58828"><META NAME="dc.title" CONTENT="NASA - Space Shuttle Main Engines"><META NAME="dc.format" CONTENT="text/html"><META NAME="dc.date.modified" CONTENT="2009-07-16"><META NAME="dc.language" CONTENT="en"><META NAME="dc.publisher" CONTENT="Brian Dunbar"><META NAME="dc.publisher.tool" CONTENT="eTouch Digital Asset Management(CMS)"><META NAME="dc.description" CONTENT="Space Transportation System"><META NAME="dc.identifier" CONTENT="http://www.nasa.gov/returntoflight/system/system_SSME.html"><!--USER DEFINED METADATA--><META NAME="dc.subject" CONTENT="Space Transportation System, Return to Flight, Space Shuttle, Space Shuttle Main Engines,Space Shuttle Boosters,Space Transportation System,ascent,booster rocket engines,launching,solid propellant rocket engines"><META NAME="dc.type.difficulty" CONTENT="Easy"><META NAME="dc.type" CONTENT="Feature Articles"><META NAME="dc.subject.mission" CONTENT="Space Shuttle (Human Exploration and Development of Space [HEDS])"><META NAME="dc.creator" CONTENT="Jim Wilson"><META NAME="dc.subject.organization" CONTENT="Johnson Space Center (JSC), Kennedy Space Center (KSC), Marshall Space Flight Center (MSFC), Stennis Space Center (SSC)"><META NAME="dc.audience" CONTENT="General Public"><META NAME="dc.type.interactivitylevel" CONTENT="Passive - very low"><META NAME="dc.subject.discipline" CONTENT="Astronautics, Astronautics.Launch Vehicles and Space Vehicles"><META NAME="description" CONTENT="Space Transportation System"><META NAME="dc.imagesearch.code" CONTENT="detail"><META NAME="dc.imagesearch.image_url" CONTENT="/images/content/107937main_system_SSME_tn.jpg"><META NAME="dc.imagesearch.image_alt" CONTENT="Space Shuttle Main Engines"><META NAME="bn_title" CONTENT="Space Shuttle Main Engines"><META NAME="dc.imggallery.tnurl" CONTENT="/images/content/107937main_system_SSME_tn.jpg"><META NAME="dc.imggallery.tnalt" CONTENT="Space Shuttle Main Engines"><!--Meta Data ends--><title>NASA - Space Shuttle Main Engines </title><!--Standard Include starts--><script src="/js/196918main_browser_message.js" type="text/javascript" language="javascript"></script> <script type="text/javascript"> /** * Browser Detect Class */ function detectBrowserClass(modern){ var nBrowser = navigator.appName; var nVersion = navigator.appVersion; var nAgent = navigator.userAgent; this.version; this.browser; this.os; this.modern = (typeof modern == 'object') == true ? modern:0; if(nVersion.indexOf('Windows') !=-1){ this.os = 'win'; }else{ this.os = (nVersion.indexOf('Macintosh') !=-1) == true ? 'mac':'other'; } if (nAgent.indexOf('Opera') !=-1){ var strIndex = nAgent.indexOf('Opera'); this.version = nAgent.substring((strIndex + 6), (strIndex + 9)); this.browser = 'opera'; } else if (nAgent.indexOf('Firefox') !=-1){ var strIndex = nAgent.indexOf('Firefox'); this.version = nAgent.substring((strIndex + 8), (strIndex + 11)); this.browser = 'firefox'; } else if(nAgent.indexOf('MSIE') !=-1){ var strIndex = nAgent.indexOf('MSIE'); this.version = nAgent.substring((strIndex + 5), (strIndex + 8)); this.browser = 'ie'; } else if (nAgent.indexOf('Safari') !=-1){ if (nAgent.indexOf('Version') !=-1){ var strIndex = nAgent.indexOf('Version') this.version = nAgent.substring((strIndex + 8), (strIndex + 11)) }else{ this.version = 2; } this.browser = 'safari'; } else if (nAgent.indexOf('Netscape') !=-1){ var strIndex = nAgent.indexOf('Netscape'); this.version = nAgent.substring((strIndex + 9), (strIndex + 12)); this.browser = 'netscape'; }else{ this.browser = nBrowser.toLowerCase(); this.version = null; } this.whichBrowser = function (){ return this.browser; } this.whichVersion = function (){ return this.version; } this.whichOS = function (){ return this.os; } this.getInfo = function (){ var info = "Browser name: " + nBrowser + "<br />" + "Browser version: "+ nVersion + "<br />" + "User Agent: " + nAgent; return info; } this.modernBrowser = function (){ var isModern = false; if(typeof(this.modern[this.browser])=='number' || this.version === null){ isModern = ( this.modern[this.browser] <= this.version || this.version === null ) == true ? true :0; } return isModern; } } // Instantiate browser detect var detectBrowser = new detectBrowserClass({ 'opera': 9, 'safari': 2, 'firefox': 1.5, 'ie': 6 }); /* Support legacy browsers*/ if(detectBrowser.modernBrowser() == true){ var css = '<link href="/css/207071main_allpages.css" rel="stylesheet" type="text/css" />'; if(detectBrowser.whichBrowser()=='firefox'){ css= css + '<link href="/css/207947main_etouch_firefox.css" rel="stylesheet" type="text/css" />'; } document.write(css); }else{ document.write(legacyMsg); } </script> <link type="text/css" rel="stylesheet" href="/css/207072main_allmodules.css"><script language="javascript" type="text/javascript" src="/templateimages/redesign/browser/js/conditionalBrowser.js"></script><script src="/js/191731main_prototype.js" type="text/javascript" language="javascript"></script><script src="/js/191696main_builder.js" type="text/javascript" language="javascript"></script><script src="/js/191704main_effects.js" type="text/javascript" language="javascript"></script><script src="/js/191701main_dragdrop.js" type="text/javascript" language="javascript"></script><script src="/js/191738main_slider.js" type="text/javascript" language="javascript"></script><script src="/js/191739main_sound.js" type="text/javascript" language="javascript"></script><script src="/js/191698main_controls.js" type="text/javascript" language="javascript"></script><script src="/js/194940main_RoundedMorph.js" type="text/javascript" language="javascript"></script><script src="/js/191745main_transitions.js" type="text/javascript" language="javascript"></script><script src="/js/191713main_global.js" type="text/javascript" language="javascript"></script><script src="/js/191734main_ScrollRegion.js" type="text/javascript" language="javascript"></script><script src="/js/191730main_PrettyCounter.js" type="text/javascript" language="javascript"></script><script src="/js/191737main_SkinnedSelect.js" type="text/javascript" language="javascript"></script><script src="/js/257141main_SkinnedSelectsearch.js" type="text/javascript" language="javascript"></script><script src="/js/191695main_Blinds.js" type="text/javascript" language="javascript"></script><script src="/js/194933main_FloatingInfoClass.js" type="text/javascript" language="javascript"></script><script src="/js/191742main_Tabs.js" type="text/javascript" language="javascript"></script><script src="/js/191702main_DropDownMenu.js" type="text/javascript" language="javascript"></script><script src="/js/194938main_may-common_rd.js" type="text/javascript" language="javascript"></script><script src="/js/4564main_index.js" type="text/javascript" language="javascript"></script><script src="/js/196917main_flash_rd.js" type="text/javascript" language="javascript"></script><script src="/js/207384main_club2_detailpage.js" type="text/javascript" language="javascript"></script><script src="http://www.nasa.gov/templateimages/redesign/flash_player/js/swfobject.js" type="text/javascript" language="javascript"></script><script src="/js/196887main_externalsource_header.js" type="text/javascript" language="javascript"></script></head><body><!--No Script Include starts here--> <!--googleoff: snippet--> <noscript> <center> <div class="site_errors"> <div class="floatType_site_error_top"></div> <div class="floatType_site_error"> <table summary="layout table"> <tr> <td bgcolor="#000000"> <font color="#ffffff"> <h2><img src="/templateimages/redesign/modules/overlay/site_error.gif" alt=""/>There's a problem with your browser or settings. </h2> </font> <font color="#ffffff"> <p>Your browser or your browser's settings are not supported. To get the best experience possible, please download a compatible browser. If you know your browser is up to date, you should check to ensure that javascript is enabled. </p> </font> <p><a target="_blank" href="/home/How_to_enable_Javascript.html">› Learn How</a></p> </td> </tr> </table> </div> <div class="floatType_site_error_bottom"></div> </div> </center> </noscript> <!--googleon: snippet--> <!--No Script Include ends here--><!--Content Body Starts Here--><div class="content_body"><!--Top Starts Here --><div class="top"><script src="/js/194928main_ShowRSS.js" type="text/javascript" language="javascript"></script><input value="" id="curr_rssurl" type="hidden"><!-- Skip navigation link --><div class="skiplink"><a href="#maincontent">Follow this link to skip to the main content</a></div><div id="top_header" class="top_header"><div class="header"><h1><a class="nasa_logo" href="/home/index.html"><span class="hide">NASA - National Aeronautics and Space Administration</span></a></h1><div id="header_form"></div><script language="javascript" type="text/javascript"> var search_list = [ ]; </script><script>createLoginForm();</script><script>createSearchForm();</script></div><div class="dropper 74" id="main-nav"><script type="text/javascript"> addMenuSupport(); </script></div></div><div class="top_audience"><ul class="audiences_nav"><!----><a name="top" id="bctop"></a><li><a href="/home/index.html">NASA Home</a></li><!----><li><span class="light_grey">    <b>></b>    </span><a href="/missions/highlights/index.html">Missions</a></li><!----><li><span class="light_grey">    <b>></b>    </span><a href="/mission_pages/shuttle/main/index.html">Space Shuttle</a></li><!----><li><span class="light_grey">    <b>></b>    </span><a href="/returntoflight/main/index.html">Return to Flight</a></li><!----><li><span class="light_grey">    <b>></b>    </span><a href="/returntoflight/system/index.html">Space Shuttle System</a></li><li id="right_menu"><ul id="utilities_nav"><li><span class="hide"><form method="post" target="myNewWin" name="emailForm" action="http://mynasa.nasa.gov/portal/util/email/nasa_emailform_2007.jsp"><input value="http://www.nasa.gov/returntoflight/system/system_SSME.html" id="url" name="url" type="hidden"><input value="Space Shuttle Main Engines" id="titleUrl" name="titleUrl" type="hidden"><input value="Space Shuttle Main Engines" id="promoTitle" name="promoTitle" type="hidden"><input value="" id="promoDate" name="promoDate" type="hidden"><input value="asan" id="flag" name="flag" type="hidden"><input value="The three Space Shuttle Main Engines, in conjunction with the Solid Rocket Boosters, provide the thrust to lift the Orbiter off the ground for the initial ascent." id="leaderSentence" name="leaderSentence" type="hidden"><input value="58828" id="documentId" name="documentId" type="hidden"></form></span><a class="icons_black icon_send" href="javascript:submitPopUpEmail();">Send</a></li><li><a class="icons_black icon_print" href="javascript:openPopUpWindowNoMenubar('/returntoflight/system/system_SSME_prt.htm')">Print</a></li><li><a class="myOverlayBookmark bookmark bottom null icons_black icon_bookmark" href="">Bookmark</a></li></ul></li></ul></div><!--Top ends Here --></div><!--Left Starts Here --><input name="menu_item_id" id="menu_item_id" value="" type="hidden"><div id="left" class="left_232"><script type="text/javascript"> var itemIdAndJSFileURL= 'returntoflight_system$/templateimages/redesign/leftnav-htmls/returntoflight_.js'; var splitResult = itemIdAndJSFileURL.split("$"); $('menu_item_id').value = splitResult[0]; var url = splitResult[1]; var defPage = '/templateimages/redesign/leftnav-htmls/home_.js'; if(url == '.js') url = defPage; document.write('<script src=' + url + ' type="text/javascript" language="javascript" >' + '</scr' + 'ipt>'); </script><!--Left Ends Here --></div><a name="maincontent"></a><!--Wide Right Starts Here --><div id="backtoTop" class="wide_right"><!-- Center Banner starts Here--><!-- Center Banner ends Here--><!-- Body starts Here--><div class="box_710_cap"><div class="top_cap_white"></div><div class="box_710 box_white box_710_white"><div style="clear:both"></div><h2>Space Shuttle</h2><div style="clear:both"></div><div class="text_adjust"><p>Text Size</p><div><a href="javascript:textSizeAdjuster('grow')" class="icons_winter icon_plus">Grow Text Size</a><a href="javascript:textSizeAdjuster('shrink')" class="icons_winter icon_minus">Shrink Text Size</a></div></div><div style="clear:both"></div><div class="white_article_wrap_detail text_adjust_me"><div class="default_style_wrap prejs_body_adjust_detail"><!-- Body starts --><!--Promo date and doctitle starts--><div style="clear:both"></div><div class="name_address"><div class="address"><span class="bold">Space Shuttle Main Engines</span></div><div style="clear:both"> </div></div><div style="clear:both"></div><!--Promo date and doctitle ends--> <A HREF="/mpg/107913main_SSME.mpg" ><IMG WIDTH="250" ALT="Space Shuttle Main Engines fire" TITLE="Space Shuttle Main Engines fire" SRC="/images/content/107914main_ssme_arrow.gif" HEIGHT="326" ALIGN="Left" BORDER="0" /></A> The three Space Shuttle Main Engines, in conjunction with the Solid Rocket Boosters, provide the thrust to lift the Orbiter off the ground for the initial ascent. The main engines continue to operate for 8.5 minutes after launch, the duration of the Shuttle's powered flight. <br /><br /> <span class="detailImageDesc">Image left: The Space Shuttle Main Engines provide part of the thrust that sends the Shuttle into orbit. <b>Click image to play video of engines firing on launch (no audio).</b> Photo credit: NASA</span> <br /><br /> After the solid rockets are jettisoned, the main engines provide thrust which accelerates the Shuttle from 4,828 kilometers per hour (3,000 mph) to over 27,358 kilometers per hour (17,000 mph) in just six minutes to reach orbit. They create a combined maximum thrust of more than 1.2 million pounds. <br /><br /> As the Shuttle accelerates, the main engines burn a half-million gallons of liquid propellant provided by the large, orange external fuel tank. The main engines burn liquid hydrogen -- the second coldest liquid on Earth at minus 423 degrees Fahrenheit (minus 252.8 degrees Celsius) -- and liquid oxygen. <br /><br /> The engines' exhaust is primarily water vapor as the hydrogen and oxygen combine. As they push the Shuttle toward orbit, the engines consume liquid fuel at a rate that would drain an average family swimming pool in under 25 seconds generating over 37 million horsepower. Their turbines spin almost 13 times as fast as an automobile engine spins when it is running at highway speed. <br /><br /> <table align="RIGHT" bgcolor="#DCDCDC" width="200" border="0" cellpadding="2" cellspacing="2"> <tr><td> <b>IN DEPTH</b><br /> <A HREF="/missions/shuttle/ssme_journal.html" >+ Preparing a Powerhouse</A><br /> <a href="/vision/space/preparingtravel/stennis_people.html">+ People Propel Shuttle Engines</a><br /> <a href="/vision/space/preparingtravel/nasa_tug.html">+ NASA Tug: Fill 'er Up</a> </td></tr> </table> The main engines develop thrust by using high-energy propellants in a staged combustion cycle. The propellants are partially combusted in dual preburners to produce high-pressure hot gas to drive the turbopumps. <br /><br /> Combustion is completed in the main combustion chamber. Temperatures in the main engine combustion chamber can reach as high as 6,000 degrees Fahrenheit (3,315.6 degrees Celsius). <br /><br /> <IMG WIDTH="311" ALT="Space Shuttle Main Engines installed on Discovery" TITLE="Space Shuttle Main Engines installed on Discovery" SRC="/images/content/107906main_SSME_assembly.jpg" HEIGHT="236" ALIGN="Right" BORDER="0" /> <span class="detailImageDesc">Image right: Space Shuttle Main Engines being installed on Discovery at the Orbiter Processing Facility at NASA's Kennedy Space Center. Photo credit: NASA/Kennedy Space Center.</span> <br /><br /> Each Space Shuttle Main Engine operates at a liquid oxygen/liquid hydrogen mixture ratio of 6 to 1 to produce a sea level thrust of 179,097 kilograms (375,000 pounds) and a vacuum thrust of 213,188 (470,000 pounds). <br /><br /> The engines can be throttled over a thrust range of 65 percent to 109 percent, which provides for a high thrust level during liftoff and the initial ascent phase but allows thrust to be reduced to limit acceleration to 3 g's during the final ascent phase. The engines are gimbaled to provide pitch, yaw and roll control during the ascent. <br /><br /> <!-- Credits starts --><!-- Credits ends --><!-- Body ends --></div><!--Related Content Starts Here --><!--Related Content Ends Here --><div style="clear:both"></div><div class="space_div"> </div><div class="back_to_top"><a href="#backtoTop">› Back To Top</a></div><div class="space_div"> </div></div></div><div class="bottom_cap_white"></div><!-- Body Ends Here--></div><!-- Comments section starts Here--><!-- Comments section ends Here--><!--Wide Right Ends Here --></div><!--Content body ends Here --></div><!--Footer Include Here--><!--Footer Starts Here--><div id="footer"><script type="text/javascript"> createFooterlogo(); createFooterContent('Jim Wilson', 'July 16, 2009', 'Brian Dunbar', 'Contact NASA', '/about/contact/index.html', '/sitemap/sitemap_nasa.html'); </script><!--Footer Ends Here--></div><!--Footer Include ends Here--><div class="background_layer"> </div><script src="/js/196888main_externalsource_footer.js" type="text/javascript" language="javascript"></script></body></html>