The nature of "space"

There are two things to consider here. First, the expansion of space. Second, we need to consider gravity. As it turns out, the gravity of a planet overcomes the expansive force where a planet is concerned. As an analogy, it is like comparing the gravitational effects of the Moon and Earth on you right now. The gravity of the Earth overwhelms the gravitational force from the Moon so that you are not drifting towards the Moon.Edited by Taq, : No reason given.

Stile did a great job of explain the other stuff. I thought I might add one thing in response to the above.If it were not for the expansion of the universe you would end up where you started. The problem here is that over large enough distances the accumulated expansion of the universe is greater than the speed of light. IOW, you would need to travel faster than the speed of light in order to get back to Earth. It's sort of like a treadmill that is spinning faster than you can run. The longer you go the more treadmill you have in front of you.