[mrguyorama]

Why would it be 2x? In terms of gravitational potential energy, you get out exactly what you put in, minus things like friction and air resistance.

Also the vast majority of the energy in an orbiting body is not in gravitational potential energy (not that you said that) but in the kinetic energy of the object moving at something like 4.75 miles per second.

The end result is that the energy an object decelerating back into atmo releases is about the same magnitude as the energy of the rocket that got it up there in the first place.

[coumbaya]

Well not 2x as the deceleration is 2x, but in total like you said, you put energy rocketing it up and sideway fast, it uses that same amount of energy going down.

[uhhhhhhh]

Most of the energy used to put it into space was to push the fuel and delivery vehicle mass not the payload, that is not present on return.