: If you build a rocket that goes indefinitely upward at 1m/s, it'll never get
: close to the surface escape velocity (it will eventually be at escape
: velocity, once you're far enough from the planet that the escape velocity
: is only 1m/s), but by definition it will ultimately get away from the
: planet. Such a rocket would need some thrust on the way up, which is the
: model Loftus is using.

: ...Not that this eliminates the basic energy requirements, of course.
: Gravitational potential is gravitational potential.

Maybe I'm wrong, but a rocket needs to accelerate all the way up, because air resistance and drag prevents it from reaching an escape velocity until it is high in the atmosphere where drag is much less.

Further you have to reach it because at some point, you're going to shut down your engines and become unpowered. You can't burn them forever.

Also I stole the equation from xkcd and I don't think it'd be wrong :-p