[trhway]

if we're going to build a 5 mile evacuated pipe while not try to use it as a prototype of a space launch? At modest 50G acceleration the exit speed would be 2.5km/s - not a production, but it would be a good test prototype to get real funding for the real deal to the top of Kilimanjaro.

[pas]

Because you'd still hit dense air at the top with 2.5km/s. You would need to go a about as high as the blackbird could fly to exit the tube with some sort of grace. (Or maybe even higher.)

http://upload.wikimedia.org/wikipedia/commons/thumb/9/9d/Com...