ISS time dilation

This morning I stumbled upon a Albert Einstein [url=http://en.wikipedia.org/wiki/Twin_paradox]twin paradox[/url] reading. Einstein took years to come out with this: If we placed a living organism in a box ... one could arrange that the organism, after any arbitrary lengthy flight, could be returned to its original spot in a scarcely altered condition, while corresponding organisms which had remained in their original positions had already long since given way to new generations. For the moving organism the lengthy time of the journey was a mere instant, provided the motion took place with approximately the speed of light. I am not a scientist so this stuff really sounds impossible to me, but it seems to be real as it was practically demonstrated in 1970. Also the GPS satellite system takes this unbelievable dilation into account and each satellite is somehow adjusted before launch to cope with it. Tonight I tried to figure out how this would affect the ISS. First of all I considered the ISS speed v as 8000 m/s or 0.00002667c (c is the speed of light). Then I calculated the epsilon factor as epsilon = sqrt ( 1 - v^2 / c^2 ) = 0.9999999996443555 Finally I applied the epsilon factor to the ISS orbit time (3013 days * epsilon) and