I know that early in the Shuttle program the idea was floated of using a recoverable Saturn 1-C instead of the SRBs.<P>This looks kinda like one of those ideas, the S1C was about 45 metres long, so that would make the Shuttle in your photo about 40m or so. The wingspan looks like about half that.
There was another neat proposal, for an "X-Plane" to explore Shuttle handling up to Mach 5, using a subscale vehicle of the final shape, powered by the same engine combinations as the X-15<br /><br />very interesting. could you link us to this subject?