I think there's a slight misunderstanding in how orbital mechanics work. Earth's gravity doesn't just drop off suddenly in space. In fact, where most shuttles and satellites orbit, they are still feeling a very significant portion of Earth's gravity. They are still being pulled to Earth at a rate of acceleration only slightly less than we feel at the surface. The difference is that their forward speed allows their, "fall," to match the curvature of the Earth. The reason the space shuttles appear to be in zero g is that they are perpetually falling. They're just moving fast enough forward to fall with the curvature of the Earth. The difficulty in getting something to orbit comes not with getting to the actual elevation, it is getting it to go fast enough to not just fall back to Earth. That's where the MASSIVE amounts of thrust needed come in. As mentioned earlier, if you're not going somewhere in the neighborhood of 17,000 mph parallel to the surface, you will fall right back to Earth.