In English, it says he ascended to heaven, which is still rather ambiguous. It doesn't mean that he flew into space into some distant region of the universe to get to heaven. It could be using the word in a totally metaphysical sense (which I think everyone assumes it is), which doesn't necessarily mean that heaven isn't a physically existing location in any way we can imagine.
I don't know what you're thinking, though. It doesn't matter where heaven is or how Jesus got there. It probably shouldn't be a problem you spend any time thinking about, because you'll never be able to prove the answer beyond reasonable doubt (even onto faithful people) because there is no evidence of the sort and there is nowhere in the bible that directly states "heaven is directly above earth" or how Jesus got there.
Also, you have to realize that "above earth" means nothing in the context you're using it. The earth isn't flat, remember? "Above the sky" at the North pole points in a much different direction than "above the sky" at the South pole.
