"Pat Flannery" wrote in message
...
It leads to a lot of assembly in orbit, more expense due to having to
design the vehicle in smaller pieces, and greater odds one component won't
make it to orbit, botching the whole assembly process- then there is the
turn-around time of the launchpad to consider.

Whereas Saturn V carried all components up with it, ensuring that if one
component went tits up, all of the others would too - including the crew.