"Spaceflight is always risky"...
When ever I hear this argument, I wish to give the poster a first-hand experience with risk...
Spaceflight is risky - just like living. There is no perfectly safe thing. You can even die inside your own bed, without ever leaving it.
But there is a difference between managed risks and having an great amount of luck. Apollo for example was not always managed risks. Lowell should know this too well. And many "in the past everything was better" apostles sure forget the other many technical anomalies in the Apollo missions. Comparing Shuttle and Apollo in that context would quite interesting, as the Shuttle has about 10 times more telemetry as Apollo. I am sure the list on the Shuttle will not be 10 times longer because of that...
That the vibrations of a rocket engine are no problem and can be tolerated, is usually said by people who have no engineering experience at all (Management people or Fan boys). Apollo 12 was nearly a failed mission, and that not because of the lightning strike, but because of the fact that oscillations of a single rocket engine of the second stage already reached 7 cm magnitude when the problematic engine was shut-off early. Just remember: the engine was installed fixed into the thrust structure, with only the structure itself acting as damper. The thrust and thrust oscillations had been constant over the burn - what allowed the magnitude to increase had been the fact, that the structure get weaker over time. Now you can argue: Hey, but the engine health monitoring shut the engine off, so all is fine. Wrong. You had been only a single point of failure away from loosing stage integrity. The vibrations happened to all flights, but a single failed pressure transducer could have been enough to keep the engine running.
Pogo suppression was added to later flights, but the first had to go without even though the problem was known after the first Saturn V test flight.
And it is not different now. The Shuttle had the advantage, that the two SRBs had a huge and pretty flexible external tank between the human payload and the SRBs. Still, the vibrations on the Shuttle are on the limit and the noise levels inside the Shuttle during launch extreme, even with helmets on. You don't hear the SSMEs because they operate perfectly silent, you don't hear them because you had been deafened by the SRBs before.
The Ares-I will be one magnitude or more worse than the Shuttle, and the mitigation of the problem shows too well, that it is not easy to get rid of the natural behavior of the SRBs. It will be interesting to see, how astronauts can read the displays (which will be quite clogged with information), while these displays vibrate relative to them (as the shock struts of the seats will produce a large part of the dampening for the crew)
But I am wondering more about people, who have to insult rational arguments by using
argument of authority ("How can they dare to know risk prevention better as NASA engineers?"). When something goes wrong because of a risk for which you as engineer or manager had been responsible, your authority is gone. So, without rational scientific argumentations, you are just entering the fanboy level. And did I mention that I think that fanboys are about the first MRO/Mission-related Objects that should be dumped during the Ares-I test flights?
Jim Lowell possibly had just one big advantage in his life over us in the terms of safety: The luxury of being unaware. Did he know that the O2 tank was damaged? If he knew, would he have flown anyway? And even worse: Let's say he knew that the tank was damaged and Apollo 13 happened like it did. Will he do the same decision to fly again in the same situation?
