I hadn't realised that the doc Wayne references (attached to this post) is the STS-121 certificate of flight readiness with missing signatures (don't know how normal that was) and caveated signatures:
I remain no go based on potential loss of vehicle however for this mission I have no intention to appeal the decision based upon ISS capability to provide CSCS
I am no go based on loss of vehicle risk (ice frost ramps). Based on appeal to administrator I have no intention to appeal his risk acceptance and concur with proceeding with the mission
In my career I have been invovled in (software) safety review/approval meetings (not space-related) but nothing as safety critical as STS. On a much smaller and less critical scale I've had occassion to think hard about whether I was comfortable with known residual risks, but I can only imagine how magnified that dilemma would have been for STS-121. I can fully sympathise with all those involved - irrespective of which personal decision they made as to the acceptability of risk.
Really looking forward to Wayne's future posts (personally and professionally).