Yesterday Sen. Richard Shelby (R-AL) spoke on the Senate floor about the impending release of the Augustine committee report and its discussion of safety—or, rather, the lack of it, in his view. An excerpt:
The Chairman of the Review of U.S. Human Space Flight Plans Committee, Norm Augustine, announced that safety would be paramount. Yet, from reviewing the preliminary information, there is only one area where mission safety was examined in the report. The Augustine report contained no safety comparison for the various vehicles considered by the panel and no risk assessment based on each option. The only safety issue identified was an assessment of how “hard” the panel thought each overall mission would be to achieve–not the safest means to complete the mission successfully. Since safety is the most important issue, these omissions are starling to some of us.
When making comparisons on the safety and performance of the various options, fundamental design differences cannot be lumped together and considered to be equal. Without an honest and thorough examination of the safety and reliability aspects of the various designs and options, the findings of this report are worthless. I would like to know why this blue ribbon panel did not examine these safety aspects.
Constellation’s vehicles have been planned and scrutinized by multiple stakeholders, all with a single goal in mind: to provide a safe and reliable human space flight system for our Nation.
The topic of safety same up Wednesday as well in a talk by Augustine committee member Jeff Greason at the International Symposium for Personal and Commercial Spaceflight in New Mexico. In the Q&A session after his speech, he was asked why the committee didn’t endorse Constellation as the “most viable” option “even though from a safety and mission assurance standpoint it’s clearly the best option.” Greason said that safety and mission assurance was considered by the Augustine committee, but that goes beyond simply the choice of launch vehicles.
“Launch is a relatively small contributor to the safety and mission assurance” of human missions to the Moon and beyond. “It is not negligible, it is not something you want to forget about, but it does not dominate the loss of crew probabilities.” Therefore, he said, it was a mistake to focus on further increasing the reliability of a relatively small aspect of overall mission risk, particularly if those choices lead you to take out safety systems in other components that because of mass restrictions. “These are false economies in terms of safety and mission assurance.”
Greason was also skeptical about the probabilistic risk assessments used to estimate the safety of various proposed systems. Most launch failures are not from random types of events, he said, but instead failures of design, testing, procedure, and the like. “If it was built wrong, it doesn’t work a lot of the time, no matter what you thought the probabilistic failure was.” The only way to “buy down” those failures, he said, is though flight experience, which is why “real boosters” have lower reliabilities than estimated when they were “paper boosters” still in the design phase.
“And the truth is, Ares 1 is, right now, a paper booster,” Greason continued. “And the further truth is, its projected launch rate is extremely low, so it will never get out of ‘infant mortality,'” that initial phase of non-probabilistic failures. “Even if Ares 1 were built exactly as planned, we would never find out whether its mature probabilistic risk assessment was or was not achievable as planned, because we would never get through the phase of life where we’re supposed to work out all the teething problems.”