Superb article!
Quote from: woods170 on 09/15/2014 02:02 pmSuperb article!Yeah, Chris did a great job with it and ATK's help ensured it was super accurate.And I'm posting the obvious here to bump this back to the top! Beats the negative thread!
Very good article. But it doesn't make me feel any better about the use of solid boosters for manned flights. All this "characterizing of voids" eerily reminds me of characterization of tile loss on the shuttles. My reading of this is that ATK and NASA are saying that since it hasn't caused any issues yet, the voids are okay. Isn't that what they said about the old joints and the shuttle tile losses.
Quote from: dbooker on 09/15/2014 03:14 pmVery good article. But it doesn't make me feel any better about the use of solid boosters for manned flights. All this "characterizing of voids" eerily reminds me of characterization of tile loss on the shuttles. My reading of this is that ATK and NASA are saying that since it hasn't caused any issues yet, the voids are okay. Isn't that what they said about the old joints and the shuttle tile losses. If that's what you got out of the article I suggest re-reading it!
It's no small problem, but no different to what most of the other companies endure with such large and complex pieces of hardware.
The difference is, ATK are honest enough and open enough to trust this site to provide updates on it.
That does not make other companies "better" at such things, by sitting on their hands and tweeting "Retweet that we're cool. Free T-shirts for the first 50!"
And would you really want a competition between a company that has decades of booster experience, and one of those other companies with nothing close to the experience?
It's those "but we may save a few million bucks" fiscal responsibility champions that will ensure we never get anywhere, fast.
Quote from: newpylong on 09/15/2014 05:22 pmQuote from: dbooker on 09/15/2014 03:14 pmVery good article. But it doesn't make me feel any better about the use of solid boosters for manned flights. All this "characterizing of voids" eerily reminds me of characterization of tile loss on the shuttles. My reading of this is that ATK and NASA are saying that since it hasn't caused any issues yet, the voids are okay. Isn't that what they said about the old joints and the shuttle tile losses. If that's what you got out of the article I suggest re-reading it! We flew Shuttle SRM's for 30 years, and the SLS SRM is based on that design, so discovering major defects is not something to be dismissed. From the article:"A year after discovering small voids between the solid propellant and the outer casing of the aft segment of a test motor for the massive 5-segment SRBs for NASA’s upcoming Space Launch System (SLS) rocket, ATK is making firm progress in their investigation and the mitigating factors toward correcting the issue ahead of the Qualification Motor -1 (QM-1) firing."If it's taking them more than a year to find the cause and the fix, that sounds like a major problem.Now maybe it could be argued that the size of the motors/castings make it difficult to iterate for finding a fix, but that would just be an argument for why SRM's are such a borderline design for this type of application. Certainly it supports NASA's desire to compete future booster suppliers.