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Low Quality Alloy Cause of Shuttle Main Tank Issue
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."
Sounds like NASA should have outsourced the work to China or Mexico. It's good enough for car makers...
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Duct Tape!
In an ideal world, wouldn't the fix be "Pick up the phone, scream at the contractor for trying to pull this shit on you, and demand a part that actually works to spec, right. the. fuck. yesterday."?
It seems like the contract must have been poorly written(and/or a blatant giveaway to our precious, precious defense contractors and their poor starving shareholders) if the solution they are ending up with is "have in-house engineers get their Macguyver on and make the gigantic tank-o'-rocket fuel on a manned vessel work somehow."
put duct tape and a patch instead of completely replacing the affected parts and rewelding ? this is so stupid its unbelievable. the shuttles tank is likely to leak when the patches get stressed on ascent due to aerodynamic forces anyway.
all they need is duct tape, didn't they do that in the Apollo 13 film ?
See: Titanic.
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?
That's the Government's stupidity for not putting a performance clause into the contract.
Or even if they didn't, they go back to LM and say, "Make it right and you eat the cost. Don't like it, then you can never bid on another contract ever."
It's interesting that a quality alloy simply put at a lower altitude would cause an issue. You'd think it was something more obvious, like a missing hyphen.
they are currently testing to ensure the repair will cause no unintended consequences
Why, without your clothes, you're naked, Miss Dudley!
idiotic engineering or bad reporting.
I can't believe that the shuttle has components with such a low FoS that a 35% reduction in material strength will put them at risk. If they are, then engineering was very sloppy, if they are not, then the 65% figure is bogus.
That this is more of a "make-work" project than anything else. Last shuttle flight is coming up, then everyone goes home. What better way to give them all a 3 month bonus than to find some previously-undiscovered issue.
These aerospace materials are extensively tested, analyzed and inspected. Paperwork with melt number, lot number and names of everyone that ever touched the material are kept.
Decide for yourself...
"Eve of Destruction", it's not just for old hippies anymore...
America had a way of producing cheap high quality al-li. However, other nations have been trying to figure out ways to produce it My guess is that L-M was trying to save a buck and used imported crap from China. We had the same issue happen just several years ago with titanium. Really too bad.
the production folks at lockheed martin, one of the largest us govt contractors, might want to look into it.
simply amazing that they weren't performing acceptance tests on each batch of material.
and shame on NASA for not making them.
they should both know better.
Absolute statements are never true
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.
And yet, shit still makes it to NASA and to the military.
So, who's talking out of their ass again?
Aren't manufacturer defects generally covered by a warranty? It should be replaced for free!
I hope this comment is well received... I could have moderated instead!
Persecutors will be violated!
Return it and demand a replacement/refund.
Rules of Conduct:
#1 - The DM is always right.
#2 - If the DM is wrong, see rule #1
NASA still has 10 "Centers". NASA still has all the "centers" it had in the Apollo era. With the end of the shuttle program, that needs to come way down. NASA Ames should be trimmed down to just the wind tunnel. The centers in Slidell LA and Cleveland OH should be closed. One of Langley and Dryden should be closed. One of Huntsville and Houston should be closed. And NASA HQ should be downsized to about half its current size.
If they supplied faulty parts make them replace it or sell their company to someone who will.
I like how there are folks complaining about NASA when the tank and alloy were manufactured by Lockheed-Martin....
Motorcycles, Robots, Space Gossip and More!
It's metallurgy.
Well, rocket science metallurgy, but still!
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!
Seven puppies were harmed during the making of this post.
But if politicians can't grab bits of the funding for their own districts, won't the entire economy collapse?
"Sometimes, I think Trent just needs a cup of hot chocolate and a blankie." -Tori Amos on Nine Inch Nails
me about space flight, is that I'm sitting on top of something that went to the LOWEST bidder. One of the original Mercury astronauts.
At least they found it in time! God knows how many more shuttles could have gone up with these bad tanks!
Ever pulled together the correlation between ALL external fuel tank issues and the contract being moved to Lockheed? Yes the foam as well. Somebody has to say it.
They where even granted a exception by the EPA on having to switch to a different foam, but they did it anyhow.
No conspiracy here, just a Bird Colonel that favors Lockheed.
Regardless of where the alloy was sourced, which part of "mottled appearance" did quality control not pick up?
Or is L-M outsourcing QC to China also.
Also kind of interesting the alloy seems to have gotten some kind of surface finish on one side only.
I wonder if this will deter future contracts and maybe even make stocks go down.
Sounds like a job for Lean Six Sigma!
Space exploration costs. Money or lives. Your pick.
During the 60s, the US opted for the former, the Russians often for the latter. Who got to the moon?
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
pssst...LM also makes the F-22 Raptor and F-35 Lightning2....just saying...
They could solve all their problems with transparent Aluminum.
Let's light this candle...
Oh, wait...
"It seems that we are at the age where life stops giving us things, and starts taking them away..." Indiana Jones