Forgot your password?
typodupeerror
NASA Space Science

Low Quality Alloy Cause of Shuttle Main Tank Issue 118

Posted by Soulskill
from the heisenberg-compensators-were-acting-up dept.
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."
This discussion has been archived. No new comments can be posted.

Low Quality Alloy Cause of Shuttle Main Tank Issue

Comments Filter:
  • Sounds like NASA should have outsourced the work to China or Mexico. It's good enough for car makers...
    • by dadelbunts (1727498) on Friday January 14, 2011 @01:44PM (#34880160)
      Not typical U.S quality. Typical U.S government contracts. Government agencies opt for cheapest price instead of quality usually. I remember when COD4 came out i was working on some contracts for the army and i saw this quote. Could never keep myself from laughing at how true it was. “Never forget that your weapon was made by the lowest bidder.”
      • by geekoid (135745) <dadinportland@ya[ ].com ['hoo' in gap]> on Friday January 14, 2011 @02:03PM (#34880488) Homepage Journal

        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.

        • by thegarbz (1787294)
          Quality is, but quality control is. The vast majority of procurement departments will take the option of ensuring that a company has the right to bid on a contract by meeting the quality requirements set out. These then get written into the contract and the buck stops there. The threat of potential legal action then somehow magically is supposed to ensure that all products will be perfect.

          A critical material order should be held on delivery pending a independent positive material identification. Though a
      • That line is much, much older than COD4.

        • by tekrat (242117)

          Try and remember that a significant percentage of slashdot denizens weren't even *born* when the shuttle started flying. Now.... get off my lawn.

        • Of course. Was never implied that COD4 made it, just that i chuckled every time i saw it.
    • "Get away from that, you don't know the components!"

      "'American' components!? 'Russian' components!? All made in Taiwan!"

      • by k6mfw (1182893)

        "Get away from that, you don't know the components!"

        "'American' components!? 'Russian' components!? All made in Taiwan!"

        Unfortunately Taiwan outsourced much of their manufacturing to mainland China.

    • No, as a metal worker I can say that the mild steel, stainless, mag and aluminum that our shop gets from China is FULL of impurity. I can tell if the steel is from America vs. China / Mexico by the amount of crap that sticks to my tungsten. If after a rod of GOOD filler rod and no dips you need to re-grind your tungsten, it isn't a pure aloy. The issue gets worse and worse the more the more specialized the alloy. Having worked in airspace, if you don't dip your tung in the Al alloy you should NEVER have

  • by Anonymous Coward
    Duct Tape!
    • If they can just get a colony of space bats [wikipedia.org] to cling to the main tank, their tough, leathery wings should provide sufficient structural integrity to keep the tank together...
      • Unfortunately, it turns out that space bats are repulsed by the insulating foam used on the tank.
  • by fuzzyfuzzyfungus (1223518) on Friday January 14, 2011 @01:38PM (#34880068) Journal
    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."
    • by jd (1658) <imipak&yahoo,com> on Friday January 14, 2011 @01:49PM (#34880268) Homepage Journal

      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?

      • by h4rr4r (612664)

        Sure there is. Either LM finds a way to give NASA a new tank or they pay someone else to do it. It might cost every dime their company is worth, but that is the risk you take.

        • by jd (1658)

          No, the ramp-up time would be well over the retirement date. Not just of the shuttle, but the IIS as well.

          That's why NASA opted for hand-crafted fixes. It was that or cancel the launch. Those were the options.

      • by Thelasko (1196535) on Friday January 14, 2011 @02:51PM (#34881084) Journal
        I'm also willing to bet that the best and the brightest at the tank manufacturing facility left shortly after they heard the shuttle program was canceled.
      • Makes you wonder if NASA was on to something in the '70s when they didn't fly the last 3 end of the run Saturn V models.
      • by timeOday (582209) on Friday January 14, 2011 @03:19PM (#34881470)
        It would take some actual evidence to convince me anybody did this knowingly. Your assumption of, "oh well, it's our last batch, I don't care if the shuttle blows up" doesn't sound very likely to me.
        • by jd (1658)

          The last launch was a "bonus run" and might never happen. NASA is responsible for certifying the product is launch-ready, not LM's employees. If the launch is scrubbed due to cheap tank defects, it's no skin off the teeth of any of LM's employees - the next-gen heavy lifter won't exist before they're permanently retired or dead, and won't use a liquid fuel tank.

      • and if they walk away with the difference in costs, well who'se going to even notice?

        I imagine that if the tank failed, blew up another shuttle, and killed another seven astronauts, an awful lot of people will notice. And Congress will call an inquiry. And constituents will demand that heads roll. And anyone and everyone associated with the tank -- working, retired, resigned, fired, or whatever -- can and will be roasted alive in the court of public opinion, fined into oblivion, professionally ruined for life, and perhaps even jailed. Never underestimate the power of the public's desire

        • by jd (1658)

          The enquiry will take years, if not decades, assuming it ever happened at all. (We have a deadlocked government in the US - if the Democrats called for an enquiry, they Republicans would block it out of spite. Same the other way round.)

          By the time any conclusion was reached, most of the former employees will be dead or overseas in a tax haven, possibly making a fortune off insider memoirs.

    • What makes you think the tank wasnt the cheapest one that met specifications. Blame the government not the contractors. They build things that barely get by the predefined margins of acceptability with the lowest cost.
      • Re: (Score:3, Insightful)

        by llung (1841162)
        Blame the government? They didn't build the tank, the contractor did. The idea is for the contractor to build the item they bid upon to the specifications. How would the engineers know that these are at 65% of the expected fracture strength? Because they have specs.
        • by poetmatt (793785)

          this is very much a chicken and egg scenario in a lot of ways.

          you have: lowest bidder, no bid contracts, government specs being too stringent, and gov't specs being not stringent enough.

          all of these occur sometimes, whether it's one independently or multiple.

          So no, don't just blame the contractor, and don't just blame the gov't. Everyone has a part in the issues here.

        • by fluffy99 (870997)

          More than likely the contract just called for the standard alloy number, AlLi-2090 I'd guess. The alloy mixture is probably correct but the heat treatment was likely not performed correctly. Add to that the contract probably didn't call for testing the materials.

          End result is certainly that the govt will pay for the rework. I've worked with Lockheed Martin before. They do contracting very well and always get paid since they have high level politicians in their pocket. We had one experience where they de

      • by smooth wombat (796938) on Friday January 14, 2011 @02:10PM (#34880586) Homepage Journal
        They build things that barely get by the predefined margins of acceptability with the lowest cost.

        Like Spirit and Opportunity, right?

        Or did you mean Deep Impact (not the movie)?

        Voyager 1 and 2? Cassini?
    • by szark (1066530)
      Things like this make me so happy to know that Congress is forcing NASA to use these same components/contractors for their new heavy launch vehicle.
      • Go civilian/commercial spaceflight!
        • Better yet, have Congress tell NASA what they want, then have NASA do all the contracts, irregardless of the senators & reps' home states.

          However, good luck with congress not fucking that up.

          • The problem with that is Congress has no goals in space. "Lets be better than Europe and China" isn't a goal for a space program. Congress likely isn't qualified to determine our progress in space. Instead, they know how to make requirements that benefit their districts.

            Either way, its a huge amount of bureaucracy, which can likely be better served by companies in it for profit, wanting to develop space flight for long-term use.
          • Ah, but then what motivation would there be for Congress to tell NASA what they want in the first place? Congresscritters control the purse strings of the national budget, which means they control what gets spent and where. Naturally, they want as much of it as possible to be spent in their state to maximize the state's economy, thus maximizing its prosperity, thus ensuring their re-election. Remove the money from the process and Congress will cease to give two damns about NASA, which will promptly die.

            L

    • by geekoid (135745)

      because there isn't a way to fix it. If they where going to fly for years, then yeah. But hwo are they going to build a new one in time for the next flight? They can't, no one can. It's not possible.

      What shuld happen is the contractor picks up the cost to fix, as well as liability from failure.

    • by Jaktar (975138)

      You can't just lay this all on L-M. For all we know, NASA gave L-M a spec that they fulfilled. It's up to the original engineers to know the nominal strength and then design in the usual safety margin. The fact that they were able to pull up records right now showing a lower quality material was used tells me that *someone* looked at it and signed off that it met whatever requirements were applicable at the time. It's not like NASA doesn't have a Quality Assurance program.

      • by Unkyjar (1148699)

        Somehow I doubt Lockheed-Martin received a contract for a main fuel tank that cracks and leaks when filled with fuel. And really, if they thought, "Hey it's good enough even with the cracks" then they really are bad people.

    • by Locke2005 (849178)
      That was somewhat my reaction as well. Why are NASA engineers working to ameliorate the problem, when the real solution should be to have the contractor that provided the faulty tank replace it (at no cost to NASA) ASAP?
  • See: Titanic.
  • That is surprising (Score:5, Insightful)

    by vadim_t (324782) on Friday January 14, 2011 @01:47PM (#34880232) Homepage

    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?

  • Low quality alloy cause of Shuttle main tank issue

    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

  • by HotNeedleOfInquiry (598897) on Friday January 14, 2011 @02:00PM (#34880426)
    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...
    • by khallow (566160)

      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.

      Why would that be expected to work? Good intentions? In testing where you have a very low "positive" rate (that is, presence of rejectable flaws in your parts), especially with humans making most of the inspections, then you tend to get a high false negative rate. So it's not surprising to me that a flaw made it this far. IMHO it's likely that this flaw has made it onto Shuttle launches before, it's just the first time it got caught at this point.

    • by pz (113803)

      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...

      And the wife of the fellow who is scheduled to fly the final mission just got shot in the head very publicly by an American terrorist. Personally, I'm OK with NASA stretching out their schedule 3 months, if that's all this is, in order to allow the captain to fly as planned.

      • by h4rr4r (612664)

        Not every nutcase is a terrorist. That word is far over used. He is a criminal, a murderer and a nutcase, so are most terrorists but the inverse is not always true.

    • by BJ_Covert_Action (1499847) on Friday January 14, 2011 @02:34PM (#34880884) Homepage Journal
      Or, alternatively, back in November when Discovery was being fueled, an on-pad engineer could have noticed a crack along the main tank that looked large enough to be suspicious and reported it. As a result, NASA delayed a launch multiple months (something which causes a hassle for other launch platforms preparing to launch, as shuttle almost always takes precedence) to figure out what was causing the main tank, a gigantic bubble filled with cryogenic, highly flammable liquid explosives, to crack since, you know, they don't want that toxic shit spraying all over their personnel on launch. Then, after performing three months of rigorous analysis to model, simulate, and test a highly complex system with hundreds of thousands of stress focal points that are subjected to extreme temperatures throughout a mission, the people that NASA pays a cubic assload of money to for being smarter than you and I finally figured out the problem, and proposed a solution.

      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.
    • by Anonymous Coward

      Revise to say

      These aerospace materials should be extensively tested, analyzed and inspected. Paperwork with melt number, lot number and names of everyone that ever touched the material are kept.

      I think there's more to this story. If these parts are considered critical, there should have been tensile tests conducted on coupons from the same melt/heat lot. If the paperwork indicates the tests were conducted and the coupons passed, either the paperwork was falsified or the parts degraded during storage.

    • by Thelasko (1196535)

      everyone that ever touched the material...

      ...no longer works there.

      fixed it for ya!

  • 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.

  • Aren't manufacturer defects generally covered by a warranty? It should be replaced for free!

    • by hurfy (735314)

      Sure, but that return freight is gonna bite ya in the ass :O

      I think the QA guy at L-M should get a free shuttle ride ;)

      That is how my dad ran his aircraft repair...the mechanic got to be the 1st passenger. You can bet all the bolts got double checked :)

  • Return it and demand a replacement/refund.

  • Downsizing NASA (Score:1, Offtopic)

    by Animats (122034)

    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.

    • But if politicians can't grab bits of the funding for their own districts, won't the entire economy collapse?

    • by ediron2 (246908) *

      Fascinating.

      Since these facilities were opened, we've added comsat, gps, ISS, and countless military/industrial/commercial space programs. NASA provides data for everything from urban planning to weather to crop planning and cultivation, and is involved in deep space research, materials science, world climate research and god knows what else.

      But Apollo and a closing space shuttle program mean these facilities should be mothballed.

      God I hate the stupid that comes out when slashdotters start speaking authori

  • If they supplied faulty parts make them replace it or sell their company to someone who will.

  • by BJ_Covert_Action (1499847) on Friday January 14, 2011 @02:48PM (#34881054) Homepage Journal
    I like how there are folks complaining about NASA when the tank and alloy were manufactured by Lockheed-Martin....
    • by thegarbz (1787294)
      Site acceptance testing? The ball is squarely in NASA's court until Lockheed-Martin come out and say they will fix this problem at their own expense.
  • It's metallurgy.

    Well, rocket science metallurgy, but still!
  • by Dunbal (464142) * on Friday January 14, 2011 @03:08PM (#34881318)

    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!

    • The radius block repair involves (extrapolating from the article) 156 strips of aluminum about 1" wide, 10" long and mmm .080" thick. That's about 124 lbs of aluminum added. According to LockMart the Al/Li tank saves 7500 lbs so you are only eating 1.6% of the weight savings.

      The NASA fellow mentioned that the problem was fracture toughness, a property not usually checked in quality tests. You can have bad material with high tensile strength and low toughness.

      • by drinkypoo (153816)

        Just another bullshit cost-saving measure making American equipment shittier. Here's a car analogy for those that need one: In 1994 Ford went from the A185 IDI 7.3 liter diesel to the T444 direct-injected 7.3 liter diesel "Powerstroke". The early 'strokes have the "left over" forged rods from the pre-powerstroke motor, and the later ones have powdered metal rods. Well I did a little research, and found that powder metal rods are almost 10% weaker than forged and have an order of magnitude worse failure mode

  • 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.
  • I wonder if this will deter future contracts and maybe even make stocks go down.

  • 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?

  • Let's light this candle...

    Oh, wait...

To thine own self be true. (If not that, at least make some money.)

Working...