Remember when the Challenger blew up ‘cuz of those damn SRBs? (I was there. I saw it w/ my own eyes) The SRBs were a budgetary compromise, this is the way the shuttle was originally supposed to look and be launched, using considerably more existing (in 1975) technology than the actual shuttle ever used. http://www.starshipmodeler.info/contest5/5_scr_21.htm