The question was what is “safe enough” threshold. If you say 3.9% isn’t, you need to define what is. The better way to count isn’t “what percent of crew” but “What percent of crew-events” because astronauts were often on multiple missions. That number is 1.64% (14 fatalities over 852 crew events) Maybe that meets your threshold, maybe not.
The point was that wasn’t explicitly defined up front…they seemed to have fallen into the same trap you did of “we’ll know it when we see it”. CCP has a loss of crew threshold requirement of 0.37%.
Fine. If you want an acceptable design parameter for expected deaths: 0%.
We do not design civilian, optional, exploratory space missions with a threshold for acceptable fatalities. There is no number of dead astronauts that we can accept as a design goal.
Unforeseeable fatalities can happen, but death rate should not be a predetermined design parameter.
The point was that wasn’t explicitly defined up front…they seemed to have fallen into the same trap you did of “we’ll know it when we see it”. CCP has a loss of crew threshold requirement of 0.37%.
We do not design civilian, optional, exploratory space missions with a threshold for acceptable fatalities. There is no number of dead astronauts that we can accept as a design goal.
Unforeseeable fatalities can happen, but death rate should not be a predetermined design parameter.