Low Quality Alloy Cause of Shuttle Main Tank Issue 118
BJ_Covert_Action writes "NASA engineers have finally discovered the root cause of the cracks that have been found on space shuttle Discovery's main external tank. The main tank, one of the 'Super Lightweight Tank' models developed by Lockheed-Martin, employs an aluminum-lithium alloy developed by Lockheed-Martin specifically for this application. The new alloy is used in various structural stringers throughout the SLWT design. Unfortunately, the batch of this alloy used in the tank that is currently mated with the Discovery shuttle appears to be of low quality. The alloy used in the stringers has a 'mottled' appearance, compared to the nominal appearance typically used in the main tank stringers (see picture in article). This appearance is indicative of a fracture threshold that is significantly lower than typical. NASA has determined, through testing, that this low grade alloy has only 65% of the fracture strength of the nominal alloy typically used. NASA engineers have devised a potential fix to the problem that they are currently testing to ensure the repair will cause no unintended consequences. NASA plans to have the Discovery shuttle ready to launch again by February 24th, 2011."
That is surprising (Score:5, Insightful)
The bad alloy is distinct enough from the good one to tell at a glance from a low res photo.
And it even seems that they had records of the unusual appearance. So the materials came in, somebody noticed and documented that this batch looked funny, but nobody thought to investigate if they might have got something other than what was specified?
Re:I guess I'm an optimist... (Score:5, Insightful)
The problem is, the fuel tank production facility has already closed. There aren't any spare parts. It could well be that the last production cycle was done on the cheap for just that reason - there's nobody to complain to, there can't be any penalties placed on those responsible, they get their last paycheck, and if they walk away with the difference in costs, well who'se going to even notice?
Re:Performance clauses (Score:5, Insightful)
That's the Government's stupidity for not putting a performance clause into the contract
And you know that because...?
I work as a QA engineer for a large defense contractor. One thing I can tell you is that we issue a lot of documents requiring our plants and our suppliers to follow a metric shitload of MIL, ISO, EN and whatnot standards, for the very purpose of meeting stringent quality requirements set forth in the contracts. It takes months, sometimes years for our products just to pass qualification and type-approval tests, and our products don't even go in space.
In short, you're talking out of your ass.
Re:Typical U.S. quality (Score:5, Insightful)
False.
Quality has been a part of every government requirement I have ever seen.
Price is another factor as well.
But hey, lets not let facts stand in the way of urban myths and hyperbole.
NASA quality has had a very demanding view on quality. No, it's not perfect. Unfortunately, when it's not perfect and something fails, it's a big deal. When that happens, no one seem to remember all the success.
The singles biggest point of quality failure is no bid contracts.
Re:I guess I'm an optimist... (Score:3, Insightful)
Re:I guess I'm an optimist... (Score:4, Insightful)
Like Spirit and Opportunity, right?
Or did you mean Deep Impact (not the movie)?
Voyager 1 and 2? Cassini?
Re:I can't help but think... (Score:5, Insightful)
There are dozens of ways low-quality material could have made it through the QA process at Lockheed that don't require some sort of communist-conspiracy, "OMG we need jobs," to explain. For instance, it could be that, since production on this particular tank model has stopped, the remaining work force was simply trying to make due with what they had, materials wise, and produce their product (the tank) as quickly as possible without giving a particular two-shits to the wind as to how sound it was since, you know, their program was getting canceled anyways. Or, yeah, it could be a jobs program. Sure.
Re:I guess I'm an optimist... (Score:5, Insightful)
Your tax dollars at work (Score:5, Insightful)
A contractor provides inferior quality alloy for a lightweight fuel tank. So NASA engineers come up with a system to brace said fuel tank, reinforcing it and fixing the problem.
The lightweight fuel tank now weighs as much as a regular fuel tank, when you include the reinforcement, but at 3 times the cost. But don't worry, people stayed employed at your expense, and that's all that matters. Yay!
Re:I guess I'm an optimist... (Score:4, Insightful)