Shuttle tiles tell tales

Gordon Small Charleston, SC — Wed, 22 Aug 2007 04:51:00 GMT

Alan, I hope you can pass this on. To my mind, there may be a relatively simple, and maybe inexpensive way to protect the entire underbody of the Shuttle, during launch. I find that the most simple way is usually the best.

It falls into the "that's a crazy idea" catageory. Maybe crazy, but if it works, it would make NASA's life easier.

This is not a joke. I'm serious. If you know someone at NASA that will take the time to talk to me, and at least listen, with an open mind. Have them e-mail me at the address I give here.

Shuttle tiles tell tales

David, Boise, ID — Wed, 22 Aug 2007 05:10:18 GMT

My question is, why can't they embed a gortex or Kevlar mesh netting into the foam as it is setting after being sprayed on the tank

Shuttle tiles tell tales

Thomas P., Manhattan, NY — Wed, 22 Aug 2007 08:34:55 GMT

The reason they don't embed any kind of mesh into the foam is likely because of weight. The tank is huge, and even seemingly simple additions add a lot of weight.

I know thats why they stopped painting the tank white; just that coat of paint alone cost several tons.

On another note, the post-flight photo of the damaged area looked pretty benign. It didn't look seared or otherwise damaged, even down to the skin.

Shuttle tiles tell tales

Damien, KL, Malaysia — Wed, 22 Aug 2007 09:06:33 GMT

Is it possible to to redesign the external tank, such that the insulation foam is applied on the inside skin of the external tank. This would eliminate the possibility of fragments of insulation foam breaking free from the outside of the tank and endangering the orbiter.

Shuttle tiles tell tales

Kyle SUlcebarger, Westerville, Ohio — Wed, 22 Aug 2007 10:48:17 GMT

There are always ways to reinforce the foam insulation, but remember the three most important factors of aircraft or spacecraft design are weight, weight, and weight.

Shuttle tiles tell tales

Dave — Wed, 22 Aug 2007 12:13:35 GMT

Duct tape

Shuttle tiles tell tales

James Viciana, Daytona, Florida — Wed, 22 Aug 2007 12:29:54 GMT

How about putting a sacrificial coating over the tiles so it, and not the tiles, would absorb the impact.

Shuttle tiles tell tales

CJ, Houston, Texas — Wed, 22 Aug 2007 12:35:39 GMT

Any time you add something to the foam, you change the insulation properties and the weight - both can affect many other things, like lift off speed, dynamics, etc. But all ideas are worth considering - with the right combination we can probably offset the extra weight and make it flyable.

Shuttle tiles tell tales

Ray, Boise Idaho — Wed, 22 Aug 2007 12:42:31 GMT

The use of the mesh has occured to me as well. It is light weight and can be mesh sized to limit the size of the piece that can be allowed to pass through the mesh.

I was in the packaging business at one time, and discovered that netting is a very inexpensive and almost error free means of packing some objects that had to be shipped on pallets or jigs.

There are net materials that can be shrunk in place and yield high strength grip on an object. Shrink in place would allow it to be applied after the foam is applied, inspected and set. It can be applied to 'high risk' areas selectively if it is not needed over the entire area of the tank.

Give the problem to a good packaging engineer and I guarantee that will solve it. There are good ones ouot there that like this kind of challenge.

By the way - has NASA checked to see if there are any commercial ventures tha twould like to put their logo on the tank. That would pay for the fix.

Shuttle tiles tell tales

David, Three Bridges, NJ — Wed, 22 Aug 2007 12:58:40 GMT

David's idea correlates with mine ... a physical barrier between shuttle and foam should eliminate the impactors. If it also serves the purpose of either eliminating foam chuncks, or at least minimizing their size, even better. Think shrink-wrap, or netting. Embedding it in the top layer of foam makes the most sense.

Shuttle tiles tell tales

Joe, Galloway, NJ — Wed, 22 Aug 2007 13:11:16 GMT

It's about weight. Every pound of Gortex or Kevlar you apply to the tank is one less pound you can deliver to orbit. Even lightweight materials such as kevlar mesh would add up to thousands of pounds if covering all of the acerage foam (the large smooth areas around the tank where the foam is approx 1" thick). It's the little bumps, wedges, connections that move and flex that cause the larger pieces of foam to fall off (Bipod ramps on Columbia, Ice frost ramps on post Columbia). These pieces are the "dangerous" ones and trying to weave a mesh or cloth around a flexible joint or into a crevice is just going to cause another problem, the mesh or cloth will move, expand contract at different rates than the surrounding foam. You've just created another release mechinism.

Shuttle tiles tell tales

James Buchanan — Wed, 22 Aug 2007 13:36:44 GMT

All this handwringing over that gouge. The leading edge panels are the real worrisome hits. If anyone thinks those tiles are an issue, go Google up pictures of Atlantis after it landed from STS-27. Streaks of white from damaged tiles that resembled a shotgun blast across the underside.

The shuttles aren't perfect, but they're far from frail. Columbia's fatal hit was a pretty unique form of damage for the shuttles. As for other systemic headaches, its actually hard to recall a time the shuttle flew that something didn't go awry.

Put it this way, you're never going to have a ship fly that doesn't take some abuse from exiting and entering the atmosphere, even Orion will see its rough patches. The proof of concept for any vehicle is its ability to take damage and carry on. The shuttles are doing pretty well in that department, all things considered. There will always be room to improve, but this doesn't render a ship non-functional by any means.

Shuttle tiles tell tales

Jeff, Atlanta, GA — Wed, 22 Aug 2007 14:01:27 GMT

Why can't they just resume painting the external tank? I know it adds weight and cost, but even that little smooth shell would seem to go a long way toward keeping foam together.

I admit to having trouble understanding how the foam would just spontaneously peel off in chunks. Could it be being initiated by an object strike? It is under such violent loading that it would split?

Shuttle tiles tell tales

Mark A. Klonfas, New Paltz, N.Y. — Wed, 22 Aug 2007 14:05:09 GMT

Regarding the message above about "crazy, but simple' ideas to protect the shuttle underbody (and the wing leading edges); could some sort of felt-like pad be glued over these areas for liftoff? It could burn off during re-entry, but would protect the tiles from ice and foam chunks during liftoff.

Shuttle tiles tell tales

Frank, Dallas, TX — Wed, 22 Aug 2007 14:21:19 GMT

The way to avoid this kind of damage is to put the vehicle on the top of the rocket instead of alongside it.

Shuttle tiles tell tales

USA worker, Titusville, Fl — Wed, 22 Aug 2007 14:59:11 GMT

Weight. I work on the shuttle, and if you could be on the MLP looking up, you'd get the true sense of scale. For every pound of weight, you either have to increase the fuel load, or decrease the payload.

Shuttle tiles tell tales

lawerance chicago il — Wed, 22 Aug 2007 15:39:49 GMT

gortex will burn at the high temp.that nasa will need

Shuttle tiles tell tales

Dave Baker, Denver, CO — Wed, 22 Aug 2007 17:42:06 GMT

The reason there is insulation in the first place is because the shuttle sits in a humid environment prior to launch with super-cold propellants in the tank--causing ice to form on the skin of the tank.

Wouldn't it be nice if no insulation was needed so the external tank could be much LIGHTER and CHEAPER. All that's needed for that is a BIG inflated bag over the tank or entire shuttle prior to launch filled with DRY air or nitrogen. Prior to starting the SSME's the back is split down the middle and pulled out of the way with light weight specra cords.

No foam, light tank, more performance, less variables. Each pound of foam not flown is a pound of payload added.

Shuttle tiles tell tales

Pete Moss — Wed, 22 Aug 2007 18:01:19 GMT

How to save the Earth from an asteroid. Blow it up. Objection, now you will just have many small pieces that will impact the Earth. The small pieces will burn-up in Earth's atmosphere. Well, suppose the smaller pieces are still too big. Keep blowing them up into smaller pieces until they are small enough to burn up.

Shuttle tiles tell tales

Joel Farbman, Huntsville, AL — Wed, 22 Aug 2007 18:49:55 GMT

You have to keep in mind that any "simple" fixes require enormous amounts of testing and might alter much more than is apparent to you and me. I am sure the engineers involved did look at many many solutions that could get the job done and still allow the shuttle to be light enough to get the required payloads (space station modules, etc) to orbit. Hey, this really IS rocket science.

Shuttle tiles tell tales

Chris McCoy — Wed, 22 Aug 2007 19:57:06 GMT

I've seen the shuttle's tank close up. A shrink netting with 2" squares to cover and heat-shrink to the tank would perhaps weigh 300lbs. As the netting shrank, the holes would contract to about an inch. I don't know why they haven't considered this solution yet. There are about 50 different polymers out there that they make this netting out of and many are for low temp shipping environments on refrigerated trucks. They would be perfect for liftoff to tank separation. Nothing larger than an inch square could come off the tank!

Shuttle tiles tell tales

John Brandau Pearland, Texas — Wed, 22 Aug 2007 21:22:23 GMT

Nobody remembers the early flights of the shuttles. Tiles on the underside would fall off during re-entry and there were no burnups upon re-entry. So,a small gash should pose no real threat when returning to Earth.

Shuttle tiles tell tales

Thomas Ashby, Calgary — Wed, 22 Aug 2007 23:35:14 GMT

They can make bullet proof book bags for kids but can't make the shuttle worry free....

Shuttle tiles tell tales

Kenneth Luedtke — Thu, 23 Aug 2007 01:02:18 GMT

I would think that any kind of netting would act like a wire cheese slicer on the foam as it shrank to fit.

Add to that the different materials would have different expansion rates.

Then due to the stress and g-forces while climbing to orbit could cause what would start as small "lines-cracks" and lead to more foam coming off the tank.

Just a thought.

Shuttle tiles tell tales

James Buchanan, Laurel, MD — Thu, 23 Aug 2007 16:57:31 GMT

Painting the foam was not about securing the foam from falling off. It never was. The foam shedding became worse after a shift in the formula over environmental concerns.

At this point, I'd say snag a few hundred illegals to go plant trees for carbon credits and go back to the original foam.

Shuttle tiles tell tales

Frank Glover, Rochester, NY — Thu, 23 Aug 2007 21:39:15 GMT

Thomas: I think the weight of external tank paint was on the order of 300 pounds, but the point is still the same. It's 300 lb. that didn't have to be carried along..

Pete: You still have the kinetic energy of a great many small pieces that will get converted into a great deal of heat in the upper atmosphere. (if you've seen how bright one small meteor can be, imagine enough mass doing the same thing, to pose a radiant energy threat below...) If it was massive enough to pose a danger, it will *still* pose a different danger as a gigaton shower of gravel. (just as ocean vs. land impacts give you a different, but still large set of unplesant results)

If you're going to use explosives of any kind (even nuclear), you want to catch the sucker early enough to *deflect* all of it to a path that misses Earth entirely...

Shuttle tiles tell tales

Thomas Ashby, Calgary — Fri, 24 Aug 2007 01:29:44 GMT

It seems to me that this foam dilemma has only reached the public conscience since the Columbia disaster. Just what was going on in all the years of the shuttle prior to that??? The visual technology of lift off has only become first rate in the past 6 years or so and you just have to wonder what the public was never made aware of until something big happened. Did many astronauts fly since the beginning not knowing exactly what was happening at and during liftoff? Did anyone actually know??

Shuttle tiles tell tales

James Wakulchyk, Calgary, AB — Sat, 25 Aug 2007 01:42:17 GMT

Actually the weight of the white paint was in the order of 3000 lbs! There is one important point that are mentioned again and again. Weight, weight, weight, weight, weight, weight, etc. etc. Repeat this word about a hundred times. Then you get an idea of the single most important issue when designing an aircraft or space system. Even a few pounds adversaly affects the performance of the system as a whole. The idea of a felt for example, would weigh thousands of pounds, and completely destroy the aerodynamics of the shuttle. That would be like wrapping blankets around the wing of a normal airplane and expecting it to fly the same. May as well rip the wings right off while you are at it.

All of the other above mentioned potential fixes, though well meaning, were beat to death by the NASA engineers already, such as mesh, etc. For various and very good reasons, they were all rejected. The original design, flaws and all, is still by far the best system.

I have to agree on the statement that the little bit of damage was completely overblown by sensationalist journalists looking for a story. In the past, the Shuttle had re-entered with whole patches of tiles missing, with no adverse effect. The Columbia disaster, however, was a hole ripped clean through the wing, and it was truly massive, on one of the hottest parts during re-entry. This allowed extremely hot gas to melt the aluminum structure inside like a blowtorch on foil. A far cry from a damaged or missing tile.

Shuttle tiles tell tales

James Buchanan, Laurel, MD — Sat, 25 Aug 2007 18:14:00 GMT

They've known about foam shedding since Columbia launched the first time. It was a matter monitored to some degree ever since that first landing. You will note that even though the ultradetailed images weren't available for Columbia's fatal flight, NASA was well aware something happened the instant it happened.

All of the astronauts that have flown on the shuttle have been aware of it from STS-2 on up. STS-1 actually shed tiles and suffered actual damage to part of its aft assembly as a result of accoustical overloading during its launch. This resulted in the first of many improvements to the launch set up (water pooled below the shuttle to absorb the shock of air compression that resulted in the damage to STS-1) and as more understanding of the problem has evolved over the course of the vehicles life has come in, improvements and changes have occurred. Challenger and Columbia represent the only two times in over a hundred launches that catastrophic failures have occurred in an extremely complex machine. Statistically, that ain't bad. Given that of the million things that could go wrong, only two things have managed to happen. No worse than a tail fin flying off a 737 or an engine turbine fracturing in midflight on a 727.

Complex machines will break. There's never been an "if", it is always "when". Mercury, Gemini, Apollo, even Skylab, all had things go awry that could have, and sometimes did, result in astronaut deaths.

This is nothing new in the world of engineering, its simply a tragedy you accept as a reality, you mourn the lost, and you move on.

Shuttle tiles tell tales

Gabe, Point Reyes Station, CA. — Sun, 26 Aug 2007 01:20:00 GMT

James,
While I agree that things have gone wrong on all of the different spaceflight types (Grissom's hatch on Mercury, Armstrong and the stuck thruster on the Agena during Gemini, Apollo 13, and the stuck solar panel on Skylab), the only Americans who died in any of these missions were on Apollo 1, and I don't consider that an engineering failure - it was actually a failure of design (the inward opening hatch and pure oxygen testing) and imagination (nobody thought anything bad could happen during a plugs - out test). Of all of the engineering feats NASA has accomplished over the years, Apollo stands out with a perfect safety record in terms of the booster itself - not one was ever lost to failure during launch.

Shuttle tiles tell tales

Thomas Ashby, Calgary — Sun, 26 Aug 2007 22:40:15 GMT

James B. Sure, just mourn the loss and move on till the next big thing. Dude, they have had the Canadarm for some 24 years now. They could have had a survelliance system a LONG TIME ago..but didn't. Please explain this peculiarity of human nature to wait for things to happen before any remedy is made?

Shuttle tiles tell tales

Frank Glover — Tue, 28 Aug 2007 00:28:33 GMT

Okay, after actually searching now (the 300 lb. figure was from memory), I'm seeing figures from 600 to 1100 lb. on ET paint weight...

http://www.aerospaceweb.org/question/spacecraft/q0285.shtml

http://www.sciencedaily.com/releases/1999/08/990816193701.htm

http://www.airliners.net/discussions/military/read.main/71382/

http://scienceblog.com/community/older/1999/C/199902325.html

But still agreed on the improvement to system performance. ANY flying machine needs to be as structurally light as safely and practically possible.

Thomas:
"They can make bullet proof book bags for kids but can't make the shuttle worry free...."

Like the "If we can put a man on the Moon, why can't we...?" argument, isn't that really an apples to oranges comparison? One doesn't imply all that much about the ability to do the other.

(And those who say the above don't mention that we haven't put a Man on the Moon...LATELY.)

Shuttle tiles tell tales

Thomas Ashby, Calgary — Thu, 30 Aug 2007 04:58:23 GMT

It was a joke Frank..sorry

Shuttle tiles tell tales

Bill Wooster Fairfax Virginia — Wed, 03 Oct 2007 13:31:17 GMT

I realilize the concern here is weight. But were talking about human lifes also. With all those great minds you have at NASA you'd think that you would be using a solid shield on the belly of the shuttle. So nothing can damage it. NOTHING!!!!!!! How about using some common sence here instead of a MBA.

Shuttle tiles tell tales

Nigel Williams — Thu, 04 Oct 2007 23:33:26 GMT

Re the ice issue on the main tank: What about simply hanging a plastic shroud over the area where the ice is forming while they are tanking, and keep the area between the shroud and the tank foam gently inflated with a flow of dry nitrogen. That way no atmospheric moisture will be available to lead to ice formation within the foam. Remove the shroud at T-20 or so while still maintaining the N flow over the area until when the white room pulls away – and most of the problem will be solved.

Shuttle tiles tell tales

John Vanatta Jr., Baxter Springs, Ka. — Sun, 21 Oct 2007 17:47:51 GMT

A chain is only as strong as its weakest link.
The manufacture of the Shuttle and its launch vehicle must be processed as carefully as is humanly possible. Take for instance the bracket assembly itself.

Here we find a connection of items that are not parralel to each other. Therefore the integrity of the so called 'cork' insulation and the aerodynamic flow of the body lines need to be very carefully maintained as this is a very important link in the chain.

Shuttle Program Manager Wayne Hale said the cracking in the cork most likely is connected to the manufacturing process.

I would like to assure Mr Hale and you my fellow concerned persons that it is not the cork insulation preparation that is faulty but the handling of said material.

This material, which is refered to as cork in order to avoid lengthy and trade secret description is actually a highly compressed and delicate material made up of many different elements and can be damaged beyond acceptable limits by touching it with the tip of ones little finger. If memory serves there are only 2-5 NM of air per square inch in its composition. It is machined and contoured to fit.
To manipulate such delicately prefabbed insulation into position without challenging its geometric integrity is akin to handling dust in the wind and is considered an artistic challenge of very demanding hand eye coordination. The tiniest mishap during handling can lead to a total loss of the item. It will suffer a chink or a void or a 'crack'.

I know, i machine the delicate and dustlike stuff (to my detriment) which is highly challenging to ones respiratory well being. It does not leave my shop with any disrepencies. None.

I have been working with Aerospace systems my entire life. Somewhere along the line the insulation is being mishandled suffering chinks or voids and or 'cracks' that accumulate air and ice and then are subjected to the force of leaving the earths atmosphere. That's not rocket science.

Perhaps Mr Hale is referring to the 'manufacture' of the 'vehicle' itself because i know that the manufacture of the items are held to near impossible tolerances and is shipped as per print.

When i have a mishap during manufacture of an item, and it happens as we are only human, said item is thrown away and a new one is made. Regardless of expected delivery time or cost.

We, the American blue collar craftsmen, dont think of the process in terms of time or dollars but consider it a mission. We know that peoples lives are at stake and we approach the challenge accordingly.

I mean no disrepect to any i only wish to clarify that the failure is not to be found anywhere outside of the Quality Control System at NASA.