“Right stuff” thinking is not a suitable commercial human spacefaring safety philosophy
The last primary factor was an acceptance of inadequate operational safety.
The public has always been concerned about the safety of America’s astronauts. The loss of lives during the American manned space program has been acutely felt by the public. After the Space Shuttle operations ended in 2011, NASA was requested by an independent safety board to review the operational safety of all Shuttle missions from 1981-2011. The primary focus was what was the real analytical probability of loss of crew from some catastrophic failure. When the Space Shuttle program began, the likelihood of having such a catastrophic failure was stated to be in the range of 1 in 1000 (1:1000). From the above chart, the retrospective analysis shows that the real analytical probability of loss of crew was only 1:10 in the missions leading up to the loss of the Challenger.
Overall, there were two catastrophic failures in 135 total missions—Challenger on mission no. 25 and Columbia on mission no. 113. The overall mission failure rate was 1:68. NASA, in the above analysis, estimated that the rate was 1:90 at the end of the program.
Clearly, this level of operational safety represents a severe lack of professionalism with respect to ensuring acceptable operational safety. While the ability to analytically understand the actual probability of loss of crew was likely poor when the Shuttle began to operate, by the time the program ended—not too much before these results were produced—this was likely not the case.