Space Shuttle Foam Fixes

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vogon13

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Machine applied foam is supposed to be the best. But there are many complex fittings and protuberences on tank that need hand application.<br /><br />I don't know if closed or open cell foam is used. Presumably, they understand the advantages and drawbacks of both types.<br /><br />If NASA has video footage of area that detached during application process, maybe there will be a clue discovered.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>
 
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skywalker01

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It was my understanding that the foam is breaking off within itself not at the bonding surface with the tank.<br />If so would that make a difference to your comments about adhesion?
 
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strandedonearth

Guest
SG, would you know if it's possible to replace the foam PAL ramps with metal or composite ramps? This would provide a more regular surface for the foam to be applied to, instead of building ramps out of foam. Of course, void spaces under the ramps would need to be vented for changes in air pressure.
 
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CalliArcale

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<blockquote><font class="small">In reply to:</font><hr /><p>It was my understanding that the foam is breaking off within itself not at the bonding surface with the tank.<br />If so would that make a difference to your comments about adhesion?<p><hr /></p></p></blockquote><br /><br />That's my understanding too, although in some cases they say it really has broken all the way through to the aluminum. (In yesterday's press conference, they showed divots that they said were the color of the primer on the aluminum underneath, which suggests it did indeed go all the way in, although that doesn't mean it had a bad bond neccesarily.) The PAL ramp piece looks like it ripped off within the ramp itself, not at the tank's surface. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>
 
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CalliArcale

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shuttle_guy:<br /><b>"Anybody remember if they abandoned the freon-free foam application process? "<br /><br />No, they did not.</b><br /><br />tomnackid:<br /><b>"Why not go back to the CFC foam?"<br /><br />Apparently the chunk of foam that hit Columbia's wing WAS the original CFC foam. It is still used in areas of the ET where the new foam will not work. </b><br /><br />Thanks, guys, now I remember what I was remembering. <img src="/images/icons/wink.gif" /> It was only on the problem areas (the hand-application spots) that the team reverted to the original foam process, because the new process is more likely to cause voids (which are worst in the hand-applied areas).<br /><br />In some respects, it's too bad we don't have comparable data about previous missions. It's hard to know if this is better, worse, or the same as previous flights when there's no baseline at a comparable level of detail. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>
 
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radarredux

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> <i><font color="yellow">I watched Griffin review that foam loss on CNN. He noted that we were lucky, and that if the foam loss occurred a fe3w seconds earlier their would have been a big problem.</font>/i><br /><br />I read somewhere (NY Times?) that in this case the Shuttle was at a relatively high altitude, so the thin atmosphere did not cause the foam to slow down dramatically.<br /><br />In the case of Columbia, the foam came off at a lower altitude where the thicker atmosphere slowed it down a lot compared to the shuttle. The end result was a high-speed impact.<br /><br />Edit: Found the same information at Spaceflight Now:<br />Timing of fuel tank foam loss saved Discovery from big hit<br />http://www.spaceflightnow.com/shuttle/sts114/050728hallock/</i>
 
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radarredux

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Question: Could the cable tray (and therefore the PALs) be moved to the far side of the ET (away from the orbiter)?<br /><br />(I apologize if this has already been brought up.)
 
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CalliArcale

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My guess is that they've put them between ET and orbiter specifically to reduce aerodynamic loads on the protruberances. But that's just a hunch. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>
 
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CalliArcale

Guest
Ah, that makes sense. So moving them would probably add weight by adding more pipe? <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>
 
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haywood

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I've spent the last day reading and re-reading all these posts and suggestions trying to gleam some glimmer of hope out of all of this.<br /><br />I'm not sure who to blame...I don't know if even know if "blame" is the right word. All the work that has gone on over the last two and a half years to solve this foam problem has come to nought. I feel so sorry for all the people who worked so hard to get this program back on the rails.<br />I feel sick.<br />And I"m sure a good proportion of you feel that way too.<br />From what I've read here, both in the last couple of days and over the past 2 or 3 years I've come to the conclusion, be it right or wrong, that NASA has been working with its hands tied.<br />This may seems overly simplistic and I've mentioned this before-as have other posters but the root of all of this foam trouble seems to have begun when NASA was mandated by the EPA to use non-CFC foam.<br />My understanding was that before the foam formula was changed, the foam shedding problem was minimal, something that was manageable and not a great risk to the Shuttle.<br />Then the environmentalists got it into their heads that NASA would be better off, and the planet would too, if they forced them to be better corporate citizens by "going green".<br />And look what happened.<br />A giant step backward that ultimately doomed a Shuttle, 7 brave explorers and...I'm dreading saying this, the entire manned space program for the next 5.<br />years.<br />For what?!<br />It just doesn't make any damn sense.<br />How is NASA supposed to get ahead when confronted by those who really don't care a lick about space anyway.<br />I say "the heck with them" and let NASA do things the way they know best. They came up with a formula that worked pretty well and someone couldn't leave well enough alone.<br />So was it worth it all you (sorry) tree-huggers?<br />Sorry but I'm steaming at this point.<br />How long will it take to redesign the ET now?!<br />6 months? 2 years?<br />There goes the rest o
 
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silylene old

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Well it seems the big foam piece that came off was a "repair patch" (see the other thread or http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=220&start=11).<br /><br />Interesting.<br /><br />One wonders how the foam surfaces are prepared before applying a patch?<br /><br />Will (some of) the other breakoff pieces be traced to non-adhering patches?<br /><br />Does this mean there isn't an inherent problem with the current (unpatched) foam? <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>
 
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silylene old

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SG, I do think it is likely investigation will confirm that it was a failed patch. Of course, we don't know yet.<br /><br />And yes, I do wonder what is the process of applying a repair patch. <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>
 
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gawin

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Simple Fix for the foam...........<br />NASA should just take a look back at the first few shuttle missions like STS - 1 where the faom was placed on the INSIDE of the nice prety white tank. They did away with this due to the higher cost of putting the foam on the inside of the tank and the aditional weight of the paint on the outside. <br /><br />well after now 2 groundings, billions of dollars spent on redoing the tank and the loss of 7 peoples lives one would think that the simple solution is to just use the old proven safe tank design.<br /><br />why has no one thought of this at NASA. Why has no one in the press bothered to ask this of them. If the foam keeps falling off put it back on the inside of the tank!!!!<br /><br />sorry if this sounds a bit like a rant.<br /><br />gawin
 
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starbaby57

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Sorry I am late to this thread but I cannot help but note a general agreement among many peoples' intuitive sense that the answer to the foam problem lies in imbedded fiber "re-bar" and/or a "thicker than paint" shell over the entire ET. I cannot care over an extra 800, 1200, or 1600 pounds of weight if it means the difference between flying again and not. Most payloads are not at the maximum cargo capacity of the orbiter anyway. I have to believe these are the avenues to pursue. How long would a redesign of the tank take to reroute the offending lines and wiring to the other side of the ET? (WAG...)
 
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igorsboss

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I'm worried about the spectra net, as it may make the problem far worse. The foam would no longer be able to detach and fall away cleanly. A small failure may initiate a cascade of subsequent failures.<br /><br />As it stands now, if a chunk of foam falls off, all we have to worry about is what it hits on the way out. If it detaches cleanly and falls away without hitting anything, no problem.<br /><br />I think that accepting the foam's failure logically leads to increased shielding.<br /><br />One idea is to attach a temporary shield to the belly of the orbiter, but I'd be very wary of anything touching the orbiter except the existing tripod mount.<br /><br />NEW IDEA:<br />Add a new wing to the shuttle stack. The purpose of this wing would be to deflect any falling tank debris away from the shuttle's tiles. This wing would be thin and wide, and attached to the external tank's tripod struts. The wing's location would be roughly equidistant from the tank and the shuttle's heat shield, but would touch neither the tank nor the heat shield.<br /><br />This wing would be expendable, detaching and falling away with the external tank. This monolithic wing would contain no control surfaces.<br /><br />Drawbacks: Such a wing would add dead weight and would present new areodynamic issues that would need to be solved.<br /><br />Rebuttal: Although the maximum payload would be slightly decreased, it would not be decreased enough to halt ISS construction.<br /><br />Advantages: Such a wing could be constructed quickly enough to get the fleet off the ground again. We would not have to revisit the ET foam issues if we had an adequate shield.
 
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ozspace

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The early flight tanks had foam on the outside (as current), but were painted white. The paint was mostly cosmetic and only added weight and possible paint flakes to any debris. <br /><br />Also, the subject of internal foam has been discussed here and one of the problems that would arise is internal shedding that would then feed into the engines, this would cause you another bad day...
 
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john_316

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<br />ok<br /><br />spectra, kevlar, different applications of polymere blends? ok what about the fire retardation sprays used in engine firewalls of cars and trucks or here is one for you too...<br /><br />In the navy my ballistic doors where sprayed with fire retardent aluminum. I can see the weight goign back up 800lbs and or 1200lbs if something like this is used.<br /><br />I know they use different degrees of fire retardent sprays on building structures when they build new office buildings. So perhaps a look there is also smart..<br /><br />If the ET could be managed on the orbiter side then we can have a September Launch of the next STS.<br /><br /><br />I dont think a major recert is needed to apply a spectra or kevlar coating on the tank on the orbiter side. This netting can be applied without a loss in aerodynamic loss or stress to the orbiter..<br /><br />You know they do have a wind tunnel at Langley where they can test the process's......<br /><br /><img src="/images/icons/smile.gif" /><br />
 
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mattblack

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Haywood, your post about the foam and the EPA was very good. In fact, I was researching for a near-identical post.<br /><br />Well done!! <div class="Discussion_UserSignature"> <p> </p><p>One Percent of Federal Funding For Space: America <strong><em><u>CAN</u></em></strong> Afford it!!  LEO is a <strong><em>Prison</em></strong> -- It's time for a <em><strong>JAILBREAK</strong></em>!!</p> </div>
 
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drwayne

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Note that SG has pointed out in a couple of threads that the foam that came off and hit Columbia was the "old" foam.<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>
 
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thinice

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It used Ripor. The entire hydrogen tank rotated in a huge lathe, two carriages moved alogn the tank: the first one sprayed the isolation, the second with a cutter cut it to the required diameter.
 
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anotheridiot

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I definitely thought a net would take care of this, or an outer aluminum shell over the tank. I am surprised that the area hasnt been problematic before. they make a wing at the leading edge of the cavities but the turbulence between the cable and 17" pipe has to be immense. I guess it is just a clean up issue, but why leave the cable and pipe exposed in that area. if the whole area was filled with foam into a rectangle, the turbulance would fall in the area, the cable brackets would act more as a stiffener for the foam.<br /><br />Also, is there a "chicken wire" reinforcement within the foam? If it were concrete there would be a rebar and 4 x 4 steel reinforcing the whole thing. With the foam being so thick some reinforcement would hold it together.<br /><br />Also, are they just too big to admit they had a good tank before and should go back to it. Even though the foam falling off seems like more of a pretreatment situation than the foam itself.
 
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anotheridiot

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What about Russia? I know their shuttle never did anything but what was their plan?<br /><br />I thought they started out considering to strap the shuttle to a rocket to get her into orbit, but it was too expensive and they could reuse not only the shuttle but the tank and boosters also. I am starting to think that if Atlantis needs to go rescue the crew, they should just strap her to a rocket and go. <br /><br />I know this isnt supposed to be about the money, but a billion dollars in upgrades to save a few million for a rocket seems to be better money wise and safety wise.
 
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tomnackid

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"Then the environmentalists got it into their heads that NASA would be better off, and the planet would too, if they forced them to be better corporate citizens by "going green". <br />And look what happened. <br />A giant step backward that ultimately doomed a Shuttle, 7 brave explorers and...I'm dreading saying this, the entire manned space program for the next 5. "<br /><br />------------------------------------<br /><br />Actually it was a piece of the old "environmentally unfriendly" CFC foam that damaged Columbia. The CFC foam is still allowed for applications where there is no viable substitute. <br /><br />I have only done a little bit of research but the only ones who seem to be crowing about the "environmentalists destroying the shuttle" are people from the Ayn Rand institute and other ultra libertarian organizations. They haven't shown any data as far as I can find that the newer foam is more dangerous (just the assumption that if its environmentally friendly it must be inferior I guess). All the data that I have heard about (this comes from the manufacturer and from NASA so take it with a grain of salt) shows that the new foam is as good or better than the original. <br /><br />One would think that if it were simply a matter of changing back to the old foam formula NASA would do it! They are allowed to use the CFC foam and it is a simple, low cost redesign. This indicates to me at least that the composition of the foam is not to blame, its the fact that the foam is there, or rather that the orbiter is in the path of the foam that is the real problem. This is an inherent design flaw the was present from the very beginning. The best and easiest solution is probably to take the weight penalty and beef up all the parts of the shuttle heat shield that are vulnerable to falling foam. After all the weight of the orbiter has gone down significantly over the years and I think its worth bringing back a few hundred pounds to keep them flying safely. Also, maybe NASA can stri
 
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