A diagram showing the components of a Space Shuttle Orbital Maneuvering System OM engine.
NASA
<a rel="nofollow" class="external text" href="http://www.shuttlepresskit.com/scom/218.pdf">Orbital Maneuvering System (MPS)</a> (PDF). <i>Shuttle Press Kit.com</i>. Boeing, NASA &amp; United Space Alliance (<span class="mw-formatted-date" title="1998-10-06">6 October 1998</span>). Retrieved on <span class="mw-formatted-date" title="2012-02-01">1 February 2012</span>.