Have there been any proposals to launch a "space station" type of assembly into LEO, then send up some engines to get it to be able to move again? Take for instance something akin to the ISS, but much simpler with less modules, points of failure, and structural elements. Then take this, put it into orbit, and bring it some more thrust with 2 additional launches.
Has anyone ever proposed having 2 symmetrical docking ports that we would attach 2 or more boosters to to extend the range of the shuttle itself? Or potentially even just one booster to the end of it, using a docking port on the end?
I was just wondering if modular construction has been proposed or used to attach anything other than science modules, cupolas, solar arrays, etc... Have we ever sent a booster into space to be attached to a docking port? Are docking ports not powerful enough to withstand the thrust unless it's directly from behind? What are the limits with this type of modular booster idea-- are there better alternatives (refueling, etc...)?
Something like this is what I was thinking (shameless KSP screenshot). I was able to slowly propel that station to the moon with those strap-on boosters, but it was extremely unstable. The only way it stabilized was when the back-boosters hit the science modules and they stopped wriggling.