The ISS maintains a low-earth orbit of a rough average of 225 miles above Earth and travels an average 17,500 miles per hour. Docking is performed by the space shuttle first maneuvering itself to match the steady orbit of the ISS.
A space shuttle will carefully approach the ISS from below. The space shuttle will open its bay doors, then at a distance of typically 600 feet below the ISS dock, the shuttle will do a slow "back flip" to allow space station personnel to do an inspection of the shuttle underside.
Once inspected, the space shuttle will very slowly approach the ISS dock, with the top of the shuttle oriented toward the ISS dock. The docking mechanism of the shuttle is in the forward cargo bay. Once contact is made, an automatic system pulls the shuttle in tight, an astronaut on the shuttle manually locks the dock, an airlock is slowly pressurized, and then finally the hatch doors are opened.
