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You are always pointed "up", but as long as you don’t accelerate too much, earth’s gravity keeps you on a circular trajectory. This is especially true if you fix the vehicle to the ground using e.g. rails. It would then be conceivable to accelerate to a high speed on ground-level rails (which is considered “free” as you can get energy delivered through the rails) until your speed is such that gravity alone does not hold you down any more and then unlock from the rails and fly off.

I did not do the maths.



You would have to build up a lot more speed if all you are going to do is decelerate once you "take-off". Also noteworthy, once you get to the escape velocity you would require an additional force just to keep you circular.


You can still have a rocket on your vehicle to accelerate further after take-off, but you certainly need to accelerate less if you already at a certain velocity than if you are stationary. Since the “certain velocity” is free by assumption (i.e. supplied by ground-based electricty generators or something similar), I don’t see how you could be off worse. But I still didn’t do the maths fully.


Air friction, perhaps? There is more air in a tangent line.


Staitght up is also wrong if you want a circular orbit.




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