[r9etb]

ISS was WAY above them (115 miles) and in a completely different orbit. Colombia is not capable of reaching ISS altitude anyway from the start, given its weight (the other 3 are lighter and for whatever other reasons, can).

Not quite. Columbia could and often did make it up to ISS altitudes. The real story is that it was too heavy to carry ISS components -- its payload capacity was significantly less than the other Shuttles.

[WoofDog123]

"Not quite. Columbia could and often did make it up to ISS altitudes. The real story is that it was too heavy to carry ISS components -- its payload capacity was significantly less than the other Shuttles."

I stand corrected. The pool of available first-hand knowledge (people who have worked in the space shuttle program) on this forum has been impressive.