Hey space nerds!
Why aren’t we using space planes for stage one yet?
Are rockets cheaper to manufacture, or is the efficiency difference just not that great in practice?
I don’t think there’s an airplane anywhere that could carry a Saturn 5. Also, airplanes don’t go very fast or very high. By the time you’re as high as a plane could take you, you also need to be going very fast. Something something rocket equation something escape velocity.
Right, but if your plane carries the rocket 10-15km straight up, and then the rocket launches from there, isn’t that more efficient? Or would a rocket to get anywhere useful be too big to carry that way?
(I mean Saturn V sure, but most rockets aren’t going to the moon, just to put satellites in orbit).
The problem isn’t “going up,” the problem is “going fast.” If you’re in thick enough atmosphere that wings and air-breathing engines are good design, you’re in thick enough atmosphere that you cannot go fast.