Getting to the International Space Station

I will be the first to admit that I am not a genius at math or science but I am really confused about the math on this one. It takes any where from six hours to two days to reach the international space station, There have been three astronauts to make it in six hours. It takes Russia two days because they have to line up with the space station before docking.



Red Bull space jump. According to Wikipedia, it took two and a half hours to go up in a helium balloon to around 24 miles up for his jump. It took Felix ten minutes to jump down.
The ISS is in low earth orbit at anywhere from 205 to 270 miles. My problem is that I know they are going farther but a balloon makes it to low earth orbit in two and a half hours and a rocket is taking six hours. You would think that the rocket could get there faster.