The key thing with Challenger is that the engineers working on the project estimated the risk to be extremely high and refused to budge, eventually being overru

The key thing with Challenger is that the engineers working on the project estimated the risk to be extremely high and refused to budge, eventually being overruled by the executives of their company. That's different than the engineers calculating the risk of failure at some previously-defined-as-acceptable level and giving the go-ahead.