Speaking of Spaceships...
A rocket has to be pretty big to deliver a payload or spaceship into orbit or beyond.
Most of that weight is fuel for the rocket.
Most of that weight of fuel is, I believe, liquid hydrogen.
What if you used gaseous hydrogen "lighter than air" instead of liquid hydrogen, a balloon if you will that is drained as the hydrogen is burned?
And used oxygen from the air instead of liquid oxygen, and a slower throttled burn.
Now I realize that rockets lofted by ballons then launched has already been proposed, but what about using the gasses already in the baloons for fuel?