Flag of the <a href="//commons.wikimedia.org/wiki/Space_Shuttle_Enterprise" class="mw-redirect" title="Space Shuttle Enterprise">Space Shuttle Enterprise</a>.  Flags of similar design for later shuttles were generally flown at the Kennedy Space Center while the orbiter was on the launch pad or on a mission; it's not clear how the Enterprise flags were used, or if it was only made after the Enterprise retired. The Enterprise flag was displayed on or near the shuttle during several phases of work by NASA and United Space Alliance employees to move Enterprise from Dulles to New York City in 2012.
<a href="//commons.wikimedia.org/wiki/User:Clindberg" class="mw-redirect" title="User:Clindberg">Carl Lindberg</a>
Self-made, with all dimensions guesstimated from looking at images of flags.  Manned Flight Awareness logo modified from <a href="//commons.wikimedia.org/wiki/File:NASA-SpaceFlightAwareness-Logo.svg" title="File:NASA-SpaceFlightAwareness-Logo.svg">File:NASA-SpaceFlightAwareness-Logo.svg</a> and <a href="//commons.wikimedia.org/wiki/File:NASA_Worm_logo.svg" title="File:NASA Worm logo.svg">File:NASA Worm logo.svg</a>.  Design based on photo of actual Enterprise flag available <a rel="nofollow" class="external text" href="http://www.edwardsflighttest.com/pics/Enterprise_Flag.jpg">here</a>; it shows a different font and shuttle graphic compared to more modern shuttle flags, and the older "Manned Flight Awareness" logo is used, from before their name change to Space Flight Awareness.  It's possible that early flags for other shuttles followed more this design.