> There was actually an exercise done to work this out, at the direction of the Columbia Accident Investigation Board (CAIB). [...] In the CAIB’s scenario, Atlantis would have launched with a four-person crew: two pilots, and two EVA mission specialists. [...]

> A Columbia rescue mission would have been the most monumentally difficult and epic space mission in history, and it would have required absolutely everything going right to bring the crew home safely. But NASA has shown time and again its ability to rise to the occasion and bring its formidable engineering and piloting expertise to bear. Instead, the worst instincts of the agency - to micromanage and engage in wishful thinking instead of clear-eyed analysis - doomed the crew.

https://www.quora.com/If-NASA-had-known-ahead-of-time-Columb...

A much more deeply researched article here:

https://arstechnica.com/science/2016/02/the-audacious-rescue...