>>12432302>I had an idea where they would place 6 SSME’s on the bottom of a shuttle ET, and then place wings and TPS on it. You could put a payload bay in the inter tank region too. Good idea?No, not if that's all you did.
If you took the Shuttle ET as a reference structure, modified it to mount RS-25 engines to the ass end inside of a shroud, added stubby X-37 style wings, and lengthened the thing to increase the gap between the two tank bulkheads and make space for a cargo bay, then developed a reusable liquid fueled side mounted booster to strap to either side, then you could make a vehicle that would be a direct improvement to Shuttle but would still be fairly shitty owing to the very large dry mass, bad wet-dry mass fraction, and booster-sustainer design.
It would be better to swap propellants for something more dense, go to a more effective TSTO design with a reusable first stage booster, and oops end up with something that converges on the Starship design.