The first time I saw this design was in this post and I was intrigued. The Martin Spacemaster from ~1970. What a cool design! Lots of SSME's, fully reusable, asymmetrical cockpit, and air breathing engines all in one.
Credit: Organic Marble (if this is not the right way to cite other StackExchange posts, please correct me)
Obviously the design was not selected for the shuttle, but how feasible was it from a technical perspective? Seems like a viable alternative for full reusability. Any glaring problems that would prevent this system from working?
In a way this seems similar in principle to Virgin Orbit's system, except Virgin is using a commercial-modified 747 as the boost vehicle.