It's not really a question of fuel but rather orbit vehicle mass. Columbia (OV-102) was the first of the orbiters to be launched into space (Challenger (OV-99) was built before Columbia but flew later). Rockwell and NASA learned how to build lighter weight orbit vehicles after Columbia was built. The orbit that the ISS flies requires more energy than the orbit of Columbia's last flight (the higher energy orbit of ISS was a consquence of Russian involvement that required a more inclined orbital plane). It is my understanding that Columbia was incapable of reaching the ISS because Columbia weighed too much. Because of its weight and age, Columbia was within a gnat's eyelash of landing in a museum. If we had to lose Shuttles, Columbia and Challenger were the best two to lose because of their age and weight.

Gary