Continually slowing it down...
The additional drag removes orbital energy from the ISS complex. The altitude of the ISS is eroded and, thanks to the physics of orbital mechanics, it actually *speeds* up. A satellite in a lower orbit has a higher mean motion (a measure of orbital velocity) than one in a higher orbit. For example, the ISS orbits the Earth in about 100 minutes at around 350km, whilst a GPS Navstar takes about half a day at a tad over 20000km.
Biting the hand that feeds IT
