[Physicist]

Furthermore, Columbia had no mechanism by which it could have docked with the ISS.

[NonZeroSum]

If the Columbia's mission had been to ISS, it would have had a docking adaptor. People are missing the point. It's not that this particular mission could have gone to ISS, but that if an Orbiter did go to ISS, it would have had a much better chance than one that, like Columbia, went out into the wilderness.