What performance improvement would a Falcon 9, for example, have if launched from such a launch site, nearly 20'000 ft up?
Still think it is worth the performance gains?
Most of the fuel used to get to orbit isnt used to go UP but to increase the velocity in the orbital direction.
Most of the fuel used to get to orbit isnt used to go UP but to increase the velocity in the orbital direction. Remember, for example, ISS travels at ~17,500 mph, and you still need to get going that fast in the horizontal direction regardless of how high up you launch from. There will be a bit of a boost because of the increased radius of the earth at that point but that alone would probably be less than one percent.
We need Mike Heney to tell us about a better site in South America.
Must be the best place on earth for SSTO launch