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Space Science

NASA's Michael Griffin Interviewed 146

Posted by ScuttleMonkey from the still-a-long-way-to-go dept.
richvan writes "NASA administrator Michael Griffin was recently interviewed by the Orlando Sentinel about his first nine months on the job. He covers topics such as foam, Challenger, Mars, the budget, the astronaut corps and intelligent design. Describing the reasons for the foam loss, he states 'Cycling of the tanks with cryogenic propellants - in fact, [super-cold] liquid hydrogen, because we don't see this problem with liquid oxygen - causes or exacerbates voids in the bond between the foam insulation and the tank and produces cracks in the foam. If and when those cracks propagate to the surface, with a crack connecting a void to the surface, then you have a mechanism for cryopumping. When the tank is cold, air is ingested. It liquefies and goes into the voids. Then as the tank empties and the [air] warms up and evaporates, the resulting pressure blows the foam off.'"
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NASA's Michael Griffin Interviewed More

NASA's Michael Griffin Interviewed

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  • What the hell is this (Score:4, Insightful)

    by FireballX301 ( 766274 ) on Monday January 30, 2006 @05:19PM (#14602309) Journal
    How, exactly, to you go from discussing the technical aspect of space fuel tank construction, to starting a debate on friggin intelligent design?

    Orlando Sentinel = troll.

    • SETI? (Score:2, Insightful)

      by PornMaster ( 749461 )
      Well, if you see ID for what it really is, a front for religion, mightn't finding intelligent life well outside the scope of religion (which talks about man on earth as being God's little LEGO guys) pull a bit of the rug out from the ID folks?

    • Maybe because this was a interview, not a friggin discussion on the technical aspects of space fuel tanks construction.

    • How, exactly, to you go from discussing the technical aspect of space fuel tank construction, to starting a debate on friggin intelligent design?

      This is an interview on several topics relevant to NASA. If you read the article, you would see that they were not debating intelligent design. The interviewer asked if NASA should be mindful of it. Obviously, some people in the USA believe in it, most do not. Part of NASA's job is to search for clues about the creation of the universe, solar system, Earth, and

  • He says intelligent design is a myth! (Score:3, Funny)

    by Anonymous Coward on Monday January 30, 2006 @05:21PM (#14602322)
    ...in the case of the shuttle.

  • Hubble mission still a possiblity! (Score:5, Insightful)

    by alanh ( 29068 ) * on Monday January 30, 2006 @05:26PM (#14602379) Homepage
    Orlando Sentinel: Whats the status of a Hubble [Space Telescope] servicing mission on the shuttle?

    Griffin: If the shuttle performs as we expect in May, we will have the data that we need to go forward now with completion of the station. And as Ive said, if all that turns out positively, we will do a Hubble mission.


    From my perspective, this is possibly the best news here. Hubble actually generates science whereas the ISS seems to do less interesting things [nasa.gov].

    • Re:Hubble mission still a possiblity! (Score:1, Interesting)

      by Anonymous Coward
      Griffin said the risks involved in a Hubble mission are the same as an ISS mission. Further proof that O'Keefe, the previous administrator, is a tool. I never liked O'Keefe from the beginning.
    • The ISS cannot do anything until the station is staffed with adequate number of astroengineers and researchers.

      To make that happen, it has to have a capacity of evacuating the entire staff in case of emergency.

      To make that happen, it has to have a vehicle(s) capable of carrying back 10+ humans to the Earth. Also it requires more ports to hitch vehicles.

      Since we have no vehicle capable of doing such in a foreseeable future, you can imagine the fate of the ISS in the next decade or so.

      • Major NASA cock up (Score:2, Interesting)

        by Oldsmobile ( 930596 )
        My impression on the text is, that the shuttle (and thus the ISS) is bleeding NASA dry. They should logically cut and run as far as the shuttle goes, but then they lose the ISS which they have spent alot of money on.

        This could of course happen anyway, if the economy crashes and there is more war and NASA gets slashed, but even so, science and the other stuff that is really very good and cost-effective, like space probes, hubble and satellites will get less money.

        I still think exploring other ways of saving
      • To make that happen, it has to have a capacity of evacuating the entire staff in case of emergency. To make that happen, it has to have a vehicle(s) capable of carrying back 10+ humans to the Earth. Also it requires more ports to hitch vehicles.

        Or, as a stretch, bolt on a couple of russian re-entry modules that you can cram 3 or 4 guys into? Why burn billions to develop another white elephant über ship when you can take care of the problem with a few tin cans developed in 60s and proved numerous times?
    • Yes, but you should also compare the cost of a single Hubble servicing mission than building a hubble replacement and launching it on an Atlas V.
      • No you don't. We've already got a "replacement" scheduled to go up (although it will be better in some ways, it won't duplicate everything Hubble can do). The thing is, the replacement, the James Webb Telescope, won't go up before 2012, and Hubble is the only available optical space telescope until then. Let it die, you lose optical space-based observations until 2012 at the earliest.

        There's zero chance to build and launch a duplicate Hubble on the timescale of a repair mission plus a few years.

  • Now that's hostile (Score:5, Funny)

    by AKAImBatman ( 238306 ) <<moc.liamg> <ta> <namtabmiaka>> on Monday January 30, 2006 @05:27PM (#14602389) Homepage Journal
    Q: What about the foam.
    A: We'll see how the changes work.
    Q: But what if there's more foam.
    A: That would be bad and we'll have to figure it out.
    Q: But what if the foam destroys the space program!
    A: I don't want to talk about it.
    Q: But what about THE FOAM?!
    A: NNNNgggghhhh....
    Q: What if the foam makes another Challenger happen?
    A: The Challenger was a sad accident.
    Q: How do you think you've changed things? (Like with the foam?)
    A: NNNNnnnnnggghhh!
    Q: Do you think foam is intelligently designed?

    That pretty much sums it up.
    • Hah. That is funny. Props.
    • Foam caused the Columbia to become damaged, and subsequently be destroyed on re-rentry.

      A bad seal cause the Challenger to explode.

      Get your disasters right! (granted we have too many to choose from...)

      • RTFA. First he's stuck on the foam, then he unhelpfully kicks off on the Challenger anniversary.

        BTW, look out for that...

        *WHUMP*

        foam.

        Never mind.

  • Tempurpedic Foam? (Score:5, Funny)

    by dotslashdot ( 694478 ) on Monday January 30, 2006 @05:34PM (#14602450)
    Maybe they should use Tempurpedic mattress foam. Instead of damaging the shuttle, it would just conform to the shape of the portion it struck, resulting in a night of wonderful sleep for all of Mission Command.

  • Duct Tape (Score:2, Funny)

    by Bananaas ( 950442 )
    If and when those cracks propagate to the surface, with a crack connecting a void to the surface, then you have a mechanism for cryopumping. When the tank is cold, air is ingested. It liquefies and goes into the voids. Then as the tank empties and the [air] warms up and evaporates, the resulting pressure blows the foam off.

    How about this idea... DUCT TAPE! It might also solve that so-called heat tile problem...

  • Fix foam again? Start anew? (Score:2, Interesting)

    by Anonymous Coward
    I followed the documentary some time ago as they outlined the new procedures in applying the foam since the Columbia disaster in 2003. I witnessed as they applied new layering techniques for the foam and implemented space walk tile recovery and repair technologies. Quite frankly, I wasn't convinced then and am even more skeptical now with foam separations occurring from recent launches.

    Has anyone heard or read of any new technologies to replace the current foam application completely? Does anyone have an
    • 20 years of Saturn incidents

      There were no operational failures. How's that for a quick statistical comparison?

      KFG
      • There were no operational failures. How's that for a quick statistical comparison?

        There were also only 13 flights. The Space Shuttle also experienced zero operational failures within the first 13 flights. (It was the 25th flight, I believe, when the Challenger was lost.)

        I'm not really saying that the Saturn V would have seen as much failure (it certainly wasn't as sophisticated of a design as the Space Shuttle), but it certainly wasn't flown for as long or as often. If you take the Apollo capsules into account as part of the complete space vehicle, it actually has a much poorer track record.

        The truth is that the Space Shuttle is a marvel of engineering. The problem is that it was supposed to be a very focused piece of equipment (a shuttle to get people up and down) and ended up having to fill the jack-of-all-trades, master-of-none role. Thanks Nixon.
        • . . .it certainly wasn't as sophisticated of a design as the Space Shuttle

          The shuttle is a more complicated design. There is a difference.

          If you take the Apollo capsules into account . . .

          I was very careful not to do that. :)

          The truth is that the Space Shuttle is a marvel of engineering.

          In the sense that you look at it and shake your head in wonder and disbelief, yeah.

          KFG
          • The shuttle is a more complicated design. There is a difference.

            Oh no, it's quite sophisticated in its design. Just about every scrap of technology at the disposal of our engineers went into creating the Space Shuttle. Unfortunately, the budgets given to the engineers to make the Shuttle into an all-in-one-dream-machine ended up also making it a more complicated design in addition to it being sophisticated.
        • "The truth is that the Space Shuttle is a marvel of engineering"

          I think the Space Shuttle is a marvel of Congressional pork barreling, Air Force mission creep, barely held together by the heroic efforts of some sharp engineers, working under hostile management.

          Marvel of how not to do engineering if you ask me.
          • Personally knowing some of the Shuttle engineers, they will say EXACTLY that. If left to the orginal ideas w/o porking they would have had something simple, safe and sturdy. The Shuttle is over-engineered. OR maybe I should say it had too many requirements to meet that were "critical".
        • "The Space Shuttle also experienced zero operational failures within the first 13 flights."

          It had some close calls, though. John Young had to take manual control during part of the re-entry on the first flight because the aerodynamics didn't match the model programmed into the computer, tow of the APUs caught fire on another flight (I seem to remember they actually exploded after the landing), and one pilot almost stuffed up the landing.

          To be fair, one of the early unmanned Apollo flights had two engines ou
      • Not like they didn't come close [yarchive.net]... (search for "pogo oscillation")
    • IIRC there were no foam related failures untill they removed freon from the process.

      I propose giving the EPA the finger and using the really old un-PC foam process until a suitable replacement has been built and tested.

      • You could not be more wrong.

        The foam had been causing problems since mid eighties.

        The NASA was given exempt on the freon ban (of 1997?), and even thought they did change the formula, the pieces of foam believed to have caused the Columbia disaster were using the old formula (with freon).
    • "Does anyone have any percentage or statistical data illustrating the success to failure ratio of past Shuttle deployments to (say) Saturn rockets (or past similar systems)?" No doubt a few minutes work with Google, and you'd have one. But something far more interesting would be say, ratio of engineers:management compared to Saturn and Shuttle. Or even engineers salaries:management salaries compared to accidents.

      • Re:Fix foam again? Start anew? (Score:5, Interesting)

        by cyclone96 ( 129449 ) on Monday January 30, 2006 @07:02PM (#14603054)
        Engineers salaries:management salaries is probably higher on NASA programs than about anywhere.

        While working level engineers who work directly for NASA are paid fairly competitively, government rules cap salaries of management. Everything is defined by the federal payscales, available here [opm.gov]

        An engineer with 10 years of experience is typically a GS-13. In Houston, for example, he's making somewhere around $90,000/year. His immediate manager is probably a GS-14 making around $105k, and that guy's boss is probably a GS-15 who makes around $130k. The numbers vary depending on years in service. Most astronauts are falling into these ranges as well.

        Griffin, as the head of NASA, is paid on the SES (Senior Executive Service) scale, which caps out at $162,000. That's here. [opm.gov]

        Contractor management is a little better (the CEOs of the likes of Boeing and Lockheed can pull in over $10 million annually with bonuses and stock), but it's very unusual to run into a NASA contractor (manager or otherwise) making more than $200,000/year.

    • Has anyone heard or read of any new technologies to replace the current foam application completely?

      Yes. The form application process will be made moot by replacing the shuttle with the Crew Exploration Vehicle [wikipedia.org].

    • Does anyone have any percentage or statistical data illustrating the success to failure ratio of past Shuttle deployments to (say) Saturn rockets (or past similar systems)? It would be a nice graph comparing the ~20 years of shuttle incident vs. ~20 years of Saturn incidents (or similar). Surely, those studies have occurred somewhere.

      You can't usefully compare Shuttle to Saturn any more than you can compare apples to oranges. Among other things, Saturn doesn't face the re-entry and landing phase, and is

      • "In other words, contrary to popular belief, the difference in reliability between Shuttle and 'more traditional rockets' is insignificant."

        The difference is, when a shuttle launch is 'unreliable', you lose an irreplaceable multi-billion dollar spacecraft and kill the crew... when, say, a Soyuz launch is 'unreliable', you lose a launcher that you were going to throw away anyway, and the crew get an exciting ride.

        Heck, if I remember correctly one Soyuz even survived entering the atmosphere backwards: try tha
        • It is all about designing stuff without getting yourself cornered - always have a way out

          On Soyuz, if booster fails, there is a small escape rocket that is capable to carry the craft up and away far enough to clear the explosion (happened twice I believe)
          And if navigation, etc. fails during the descent, the shape and mass of the lander is just so it is going to eventually perform a ballistic reentry. The crew would have to endure much higher than normal G forces but likely to be alive (happened several t

        • Re:Fix foam again? Start anew? (Score:4, Informative)

          by DerekLyons ( 302214 ) <fairwater.gmail@com> on Monday January 30, 2006 @11:53PM (#14604596) Homepage
          In other words, contrary to popular belief, the difference in reliability between Shuttle and 'more traditional rockets' is insignificant."

          The difference is, when a shuttle launch is 'unreliable', you lose an irreplaceable multi-billion dollar spacecraft and kill the crew...

          Only in some fantasy world where every 'unreliable' launch ends in complete vehicle failure. Here in the real world, we've already had two launch failures - one destroyed the vehicle, and the other resulted in an Abort-to-Orbit. (The resulting orbit was too low for the payload, so they landed and flew it again later.) Yes, there are scenarios that lead to a complete LOCV or LOV - but there are also many more that lead to a crew and craft standing on Terra Firma making brave statements at the press conference after.
          when, say, a Soyuz launch is 'unreliable', you lose a launcher that you were going to throw away anyway, and the crew get an exciting ride.
          In a universe where the Soyuz was (unlike everything else) perfect, and everything else imperfect - that would be true. Here in the real world where the Soyuz emergency escape system performed marginally the one time it was used, and where Soyuz seems to have an ongoing problem with automatic sequences... I'd suspect it's not true.

          Soyuz has had two launch accidents - in the first (a fire on the pad) the was not engaged, which meant the crew had to beg the ground to activate it - which they finally did with less than a second between activation and the launch vehicle exploding. In the second, the first stage failed to seperate - and again, the automatic system failed, requiring manual intervention, and again - almost too late.

          Heck, if I remember correctly one Soyuz even survived entering the atmosphere backwards: try that with a shuttle and see how far you get.
          You don't remember correctly.

          Let's see - Soyuz re-entry accidents; six that I can think of offhand, two of which were fatal - and the remaining four only missed being so by sheer luck. (Out of 87 flights, and not mentioning at least five landing accidents.) Shuttle - one reentry accident, fatal. (Out of 114 flights, with only one landing accident.)

          Which vehicle has the worse record? The bald fact is that Soyuz, in 87 flights, has racked up a worse record in every single category you can name when you compare it to the Shuttle's record in 114 flights.

          • "Here in the real world, we've already had two launch failures - one destroyed the vehicle, and the other resulted in an Abort-to-Orbit."

            No, you've had three. Two destroyed the vehicle, one would have destroyed it, if the crew hadn't overridden the computers that wanted to shut down two of the three engines.

            Columbia was a _launch vehicle_ failure.

            "The bald fact is that Soyuz, in 87 flights, has racked up a worse record in every single category you can name when you compare it to the Shuttle's record in 114

            • "Here in the real world, we've already had two launch failures - one destroyed the vehicle, and the other resulted in an Abort-to-Orbit."

              No, you've had three. Two destroyed the vehicle, one would have destroyed it, if the crew hadn't overridden the computers that wanted to shut down two of the three engines. Columbia was a _launch vehicle_ failure.

              Count Columbia how you will, the facts remain the same. The difference in reliability (considering launch accidents) between the two vehicles is statisticall

          • As an engineer you look at many things, one of them is trends. The shuttle has been getting progressively worse with time. That is why it is being replaced with the CEV [wikipedia.org]. The Soyuz on the other hand has been experiancing less failures with time - most of the failures you cite were early in the development cycle and have been resolved. The Soyuz has been so successful that (a) NASA is purchasing Soyuz flights [space.com] and (b) China is implementing the Soyuz design for their own space program. Like it or not, the Soyuz

            • As an engineer you look at many things, one of them is trends. The shuttle has been getting progressively worse with time. That is why it is being replaced with the CEV. The Soyuz on the other hand has been experiancing less failures with time - most of the failures you cite were early in the development cycle and have been resolved.

              In fact - the Soyuz has *not* been getting better with time. Out of (IIRC) six flights of the TMA mark to date, four have had significant problems. When you look at accident

    • You know, I'm sure the NASA engineers know a lot more about the foam than some armchair Discovery Channel-watching Anonymous Coward. I'm sure you are not convinced, but I'm also pretty sure that you don't know what you're talking about.

  • Thermal Cycling of Liquified Air (Score:3, Insightful)

    by CruddyBuddy ( 918901 ) on Monday January 30, 2006 @06:10PM (#14602724)
    Let me see if I have this right...

    A micro crack occurs.
    Atmosphere fills the voids.
    The atmosphere liquifies inside the voids.
    When the LH is removed, the liquified atmospheric gases are returned to gaseous form.
    The change in pressure blows out the foam from the inside, because the liquid air is gasified within the foam crack and has nowhere to go.

    Result: sporatic delamination.

    Where I come from we have to deal with this all the time. They are called pot-holes!

    • True, potholes are exactly what the foam failuers seem to match. One solution is to never let the tanks thaw. Another is to simply use the tanks as they were originally designed, as launchable raw materials for space construction so you never use the same one twice, but that ran into fascinating budget and design problems which look insoluble.

      The solution is to scrap the Space Shuttle: it was a badly designed source of boondoggles, and there are a half-dozen solid industrial projects to replace it, such as

  • New Foam Idea (Score:4, Interesting)

    by Billy the Mountain ( 225541 ) on Monday January 30, 2006 @06:10PM (#14602730) Journal
    Hey, I know, put the foam insulation on the inside.

    BTM
    • Actually, I think that's brilliant. Have to make it not absorb and hold onto too much fuel, though.

      • Re:New Foam Idea (Score:5, Interesting)

        by Syberghost ( 10557 ) <syberghost@@@syberghost...com> on Monday January 30, 2006 @08:35PM (#14603541)
        Insulation on the inside means you have to make the tank larger to hold more fuel.

        Larger tank means more metal. More metal means more weight. More weight means more fuel. More fuel means more cold. Tricky balance there. Remember, this is the tank where they stopped painting the foam because the paint added too much weight.

        Also, it'll be hard to find a porous material that doesn't absorb hydrogen, the smallest atoms in existence.
        • The volume of the foam does not have to be that much since it could be mostly open-cell - all it has to do is prevent convection reaching the outer skin. Once the skin heats up enough when the liquid level drops, any remaining H2 in the foam will become gas and help push the last of the liquid H2 out. Also, even if the usable tank volume goes down, the volume - weight relation for a tank is cube - square, so it isn't that big a hit, considering the safety improvement and the fact that the oustide foam weigh

    • Re:New Foam Idea (Score:3, Informative)

      by microarray ( 950769 )
      Good one, but someone beat you to it.
      http://www.cnn.com/2003/TECH/space/11/25/sprj.colu .shuttle.fix.ap/ [cnn.com]
    • Insulation on the inside was done on the S-IVb. The only reason you couldn't do it for the shuttle is that you would have to completely redesign the tank.

            Brett

  • What about Propellant Cycling ? (Score:5, Interesting)

    by DumbSwede ( 521261 ) <slashdotbin@hotmail.com> on Monday January 30, 2006 @06:11PM (#14602736) Homepage Journal
    It wasn't mentioned, but does the cycling of propellants due to aborted launch attempts add significant additional strain to the foam?

    Were there any launch aborts before the final Columbia mission?
    • I think so, but that one I'm not sure about. The last successful one did have some cycling, because they had fuel tank sensor problems.

      Since the interview talks of freezing/expansion being a significant part of the problem, then yes. The more you cycle the tanks, the more cracking in the foam. In fact, it's slightly worse than that. Once cracks have formed, they'll gather moisture. When the fuel is reloaded, this will not only cause the regular cracking, but you'll get freeze-cracking from the ice forming o

    • It wasn't mentioned, but does the cycling of propellants due to aborted launch attempts add significant additional strain to the foam?

      From the interview, near the top of the page:

      Orlando Sentinel: What is the exact mechanism [for foam loss] that you now think you understand?

      Griffin: Cycling of the tanks with cryogenic propellants - in fact, [super-cold] liquid hydrogen, because we dont see this problem with liquid oxygen causes or exacerbates voids in the bond between the foam insulation and the tan

  • Look at his credentials (Score:5, Informative)

    by chickenmonger ( 614989 ) on Monday January 30, 2006 @06:37PM (#14602901) Journal
    http://www.nasa.gov/about/highlights/griffin_bio.h tml [nasa.gov]

    He's not only the author of the book I'm currently using for my undergraduate Spacecraft Systems course, but he's also got way more degrees than anyone should have. From the bio:

    "Griffin received a bachelor's degree in Physics from Johns Hopkins University; a master's degree in Aerospace Science from Catholic University of America; a Ph.D. in Aerospace Engineering from the University of Maryland; a master's degree in Electrical Engineering from the University of Southern California; a master's degree in Applied Physics from Johns Hopkins University; a master's degree in Business Administration from Loyola College; and a master's degree in Civil Engineering from George Washington University."

    I still wouldn't say he's overqualified for the job. The NASA admin -should- be one of the country's smart people.

    • Re:Look at his credentials (Score:4, Insightful)

      by diegocgteleline.es ( 653730 ) on Monday January 30, 2006 @07:03PM (#14603061)
      Shame that you don't require the same for presidents and congressmen! (Patriot Act, DRM, software patents, Iraq, Lewinsky)

    • Re:Look at his credentials (Score:3, Funny)

      by Anonymous Coward
      The NASA admin -should- be one of the country's smart people

      Just because someone received a bachelor's degree in Physics from Johns Hopkins University; a master's degree in Aerospace Science from Catholic University of America; a Ph.D. in Aerospace Engineering from the University of Maryland; a master's degree in Electrical Engineering from the University of Southern California; a master's degree in Applied Physics from Johns Hopkins University; a master's degree in Business Administration from Loyola Colle
    • You left out one:

      He is a certified flight instructor with instrument and multiengine ratings.

      I remember reading this guy's bio several years ago when he was running for some AIAA office. I was amazed.

      What posesses a guy to get that many degrees and certifications? Most people would spend their entire "career" just getting that many degrees!
      • What posesses a guy to get that many degrees and certifications?

        He realized that staying in school beats the hell out of the "real world?" Which definitely makes him smarter than you or me!

        Now back to those damn TPS reports...

  • 13 Years to go the Moon?!? (Score:4, Interesting)

    by iamlucky13 ( 795185 ) on Monday January 30, 2006 @07:10PM (#14603101)
    It really bugs me when people complain about how the first time we went to the moon it took less than 10 years from Kennedy's speech and now it takes us 13 years, or worse, that it's taking us half a century to return to the moon. Well read his answer and shutup!

    People keep asking me 'Why are you taking until 2018 or whatever it takes us to get back to the moon when we did it in eight years the first time?' The reason is that we're not being given the kind of money necessary to do that in eight years, but we are being given the kind of money necessary to do that in 12, 13, 14 years.
    • really bugs me when people complain about how the first time we went to the moon it took less than 10 years from Kennedy's speech and now it takes us 13 years, or worse, that it's taking us half a century to return to the moon. Well read his answer and shutup!

      People keep asking me 'Why are you taking until 2018 or whatever it takes us to get back to the moon when we did it in eight years the first time?' The reason is that we're not being given the kind of money necessary to do that in eight years, but we

      • I still call bullshit. You mean to tell me that since 1969 we have learned nothing about rockets, material science, or space flight? I would bet that the extra 13+ years of salaries of all of the NASA engineers costs more than the materials to just do it today with what we know.

        You don't get it, do you? A space mission is not about the materials or the technologies available. It's about ensuring everything works perfectly, ensuring there are contingency plans and backups for everything, and so on. That's

  • What about using a net? (Score:5, Interesting)

    by ChrisA90278 ( 905188 ) on Monday January 30, 2006 @07:12PM (#14603112)
    Seems to me one wway to prevent the foam from faling off in chunks is to embed a net over the foam. Make a fishnet out of Kevlar or Spectra fiber. Put the net over the foam. These fibers are strong. in the worst case the foam still comes off but not after being forced through the holes in the net and in the process being cut into many very small pieces. These fibers are stronger then stainless steel of the same size and much lighter. Of couse the other option is to re-design the tank so that the insilation is _inside_ the aluminum skin but then that adds weight
    • If a large piece breaks loose inside the net, the wind catching it at hundreds or even thousands of MPH will suddenly put a massive pull on the net. That net would then abuse the hell out of the rest of the foam on the tank. For containment like that to work it would have to cover the whole tank and not have holes like a net for wind to pass through. Think saran wrap or a giant nylon sock or something.
    • Spray the foam on the inside surface of the tank, not the outside. This seems like a no brainer. Inside the tank, there are no aerodynamic forces to rip off pieces of cracked foam.
      • I sugested this too, putting the insulation on the inside. However that means the aluminum skin needs to be made larger if the internal volue is to remain the same. Overall you'd have more weight. So you need more fuel so you need and even bigger tank and so on and so on. (Remember the "rocket equation" from high school physics?)

        NASA's follow on vehicle solves the problem nicely by stacking the payload _above_ the boster so that when hunk of "whatever" fall off there is nothing for them to impact.

  • Specifically Goddard Institute for Space Studies Director James E. Hansen's allegations of censorship by NASA's public affairs staff. [nytimes.com] According to him commisars upset with his stand on global warming have been denying journalists official access to him and censoring his lectures, papers and postings on the Goddard Web site.
  • Just Wrap the whole thing in shrink wrap, and keep out nearly all the air and moisture.
  • Griffin: We think now that we understand in substantial technical detail the mechanism by which the foam is and was liberated.

    It wasn't a liberation, it was an occupation, I tell you!!! That foam never even wanted to be liberated!

    Seriously, why not just say "detached", "stripped", or some other, more relevant word? ::rolleyes::
  • There's a guy who is required to do whatever the president wants, no matter how rediculous, and given no money to do it. Not suprising those NASA representatives turn over almost as fast as software managers.

  • ... to deal with the problem.

    1) as Billy the Mountain (225541) suggests, put the foam on the inside

    2) after every fueling, inspect (xray, ultrasound, ?) the foam, looking for crack propagation through it, stripping and re-foaming as needed

    3) change the foam to a series of interspersed layers of foam and a sealant layer

    and others, all of which are designed to prevent the cryopumping action by disrupting crack propagation through the foam to the atmosphere. All that remains is to perform some tests and analy
  • > When the tank is cold, air is ingested. It liquefies and goes into the voids. Then as the tank empties and the [air] warms up and evaporates, the resulting pressure blows the foam off.'"

    If there were cracks where the air got in some cracks, why wouldn't the air escape from the same place? I can't imagine the tank goes from freezing cold to boiling hot before the frozen air thaws completely...

    > the mechanism by which the foam is and was liberated

    He must be a Bush supporter if he thinks liberation ==

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