[He faces forward, shifting his weight slightly to make it easier on the bird. He can almost see the ruins ahead of them.]

Spaceships and rockets are different from regular aircraft. You have a different mix of metals to form specific alloys to endure the trip up and back from space. The fuel and even the engine are different.

I can't give you the exact details but that's the basics. ...I'm assuming this dragon used magic to travel through space. There's no wind or air up there.