9th February 2009, 03:40 PM
Former NASA chief Mike Griffin says the new Ares I rocket is twice as safe as existing expendable boosters.http://feeds.space.com/~r/spaceheadlines/~4/535699276
9th February 2009, 04:18 PM
I'd love to see that "probabilistic" risk assessment report.
It's not hard to believe that a solid rocket is less likely to have a failure, (barring major design flaws or limits ignored:() if you compare its inherent simplicity to the mind boggling complexity and "bleeding edge" technology of high performance liquid fuel engines like the shuttle's main LOX/LH2 engines.
But with a solid rocket even if you detect a failure in progress there isn't much you can do about it- you can't turn it off once you light it. and of all failure modes i wonder if most are in the "sudden catastrophic" category that don't allow time for crew/capsule escape systems to be useful.
A liquid fuel motor would be fully instrumented along with the fuel & oxidizer tanks and you have more choices on how to effectively handle a problem when you detect one starting to develop. I would tend to believe that with sufficient instrumentation the computers can detect and react to the majority of failure modes with ample time for crew escape if appropriate. Options also include throttle back, or shut down one engine, and depending on the configuration, may not even have to abort the mission.
What i wonder is, how much this was taken into account in that risk assessment. Also if the risk to the environment was taken into account. (Large APCP rockets have a pretty big & nasty environmental impact)
If it was my choice, for these reasons i'd rather be riding on top of a Delta-IV type LOX/LH2 rocket, than a modified shuttle SRB. ( Yeah, in my dreams!:):rolleyes:)
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