Originally Posted by
Expatrick
Extremely large payloads (to do what,) - at a reasonable cost (assuming they don't blow up) - to do what, exactly?
What manmade stuff in earth orbit and space has been doing for decades, but on a larger, more economical scale.
Or, to put it differently - a hundred years ago, why would anyone possibly need big airplanes that can fly thousands of miles? That's what steamships and trains are for...