[lmm]

It takes more energy to send something to the moon than to send it escaping the earth.

Space elevator with a railgun at the top of it maybe makes sense.

[phkahler]

>> It takes more energy to send something to the moon than to send it escaping the earth.

Sure, but far less than de-orbiting into the sun. Use the rocket to get to the moon-based rail gun where there is no atmosphere.