With due respect to NASA and its high competence, but until STS-107 foam loss was expected to be "non critical" on the whole, and the cold nights before STS-51L also were expected to be "non critical" for the management teams.
They're going to fix damage on the TPS of the Shuttle once again, which in fact just is that: a critical part of the Shuttle (that always caused issues right from the first atmospheric test flights in the 1970's). And yet they still talk about "non critical". Of course they have to do so. But people should be still aware that the entire OBSS and ET photography requirement only exists to due to the critical design flaw of the STS which is the fully unprotected TPS during ascent. Repairing a vehicle on orbit due to issues originating in its design never is non-ciritcal or usual stuff. It is nothing more than a workaround to enable the ISS assembling on schedule and budget.
