Images of Endeavour's Damaged Tiles

Roland Piquepaille writes "Neptec Design Group, a Canadian company and a NASA prime contractor for 25 space missions, was kind enough to send me exclusive images of Endeavour's damaged tiles during its last take-off. So here are some of these pictures" The pictures are pretty amazing and make the urgency of this whole thing much more amazing.

Comments

How long has this been happening?

[GodfatherofSoul]

This kind of damage MUST have been occurring throughout the history of the program. And, if it has been NASA would have been aware during the regular retiling of the Shuttle. My question is why wasn't the ice impact problem wasn't addressed long ago.

Re:How long has this been happening?

[arkham6]

Very good point. I remember back in the early 80's news reports of the shuttle coming back with 1/3rd of the tiles being gone due to faulty glue. Even when they didn't need to repalce the tiles so much, I'm sure they HAD to go over every inch with a fine tooth comb, and I'm sure that more than once they found some with holes from damage, either ice or micrometers. This whole "omg teh tiles have holes in them' thing is a reaction to the columbia disaster, and a way to show the media that 'yes, we are aware of the issue'.

Re:How long has this been happening?

[SomeGuyTyping]

They used to use different materials to manufacture and adhere the foam on the external tank, but environmentalist groups got their way and now we have a riskier space program.

Re:How long has this been happening?

[SomeGuyTyping]

from Wikipedia (http://en.wikipedia.org/wiki/Space_Shuttle_extern al_tank):

Development of the ETs thermal protection system has been problematic, and has proven a fatal weakness to shuttle mission safety. NASA has had difficulty preventing fragments of foam from detaching during flight, ever since a 1995 decision to remove chlorofluorocarbon-11 (CFC-14) from the composition of the foam in compliance with an Environmental Protection Agency ban on CFCs under section 610 of the Clean Air Act. In its place, a hydrochlorofluorocarbon known as HCFC 141b was certified for use and phased into the shuttle program. The "new" foam containing HCFC 141b was first used on the aft dome portion of ET-82 during the flight of STS-79 in 1996. Use of HCFC 141b was expanded to the ETs acreage, or larger portions of the tank, starting with ET-88, which flew on STS-86 in 1997.

Re:How long has this been happening?

[MarsDefenseMinister]

Turn in your geek card. It wasn't the 80's, and the shuttle wasn't coming back because it hadn't been to space. It was the Enterprise, it was the 70's, and it was during the development of the shuttle.

Re:How long has this been happening?

[igjeff]

Actually, some of the comments are that there is at least a perception that ice damage has increased since the return to flight after Columbia.

The thought is that since they've added an extra hour into the countdown after the external tank is fueled that there is a longer time for ice to build up, and then a great tendency for it to break off and smack the orbiter.

Oh, and for another tidbit. Ice, since its denser, and heavier than the insulating foam, is a bigger problem than the foam is when it breaks off. It takes a smaller chunk of ice to break off and smack the orbiter to cause an equivalent amount of damager to a larger chunk of foam.

Re:How long has this been happening?

[Hoi Polloi]

Is it possible to find a way to launch the shuttle with the belly facing AWAY from the main tank? That way any impacts from ice or foam would strike surfaces not critical for reentry.

Re:How long has this been happening?

[smooth wombat]

Sure. Just open the cargo bay doors, mount the tank to braces on the inside and you'll solve the problem.

Granted, you won't be able to carry any cargo but at least you won't have to worry about falling bits of foam striking surfaces critical for reentry.

Re:How long has this been happening?

[YrWrstNtmr]

Is it possible to find a way to launch the shuttle with the belly facing AWAY from the main tank?

Sure, if you redesign the entire thing. That tail sticking up kinda screws that idea.

That way any impacts from ice or foam would strike surfaces not critical for reentry.

'Non critical'. Like the windshields, flight controls, thinner skin of the body. Non critical stuff like that.

Re:How long has this been happening?

[Mr. Slippery]

environmentalist groups got their way and now we have a riskier space program.

This point about how the foam insulation process was changed has come up many times in discussions about the damage to Endeavor. And it's wrong.

It has its origin in one of Rush Limbaugh's lies. As it turns out, the foam that dealt Columbia the death blow was the old-style CFC foam. The problem was in the hand-spraying application method used on that area, which left gaps and voids in the foam.

Yes, when they first started using the CFC-free foam in 1997 there were some problems seen. Changes were quickly made to improve the adhesion.

There were also plenty of problems with the CFC foam - "popcorning" from trapped air bubbled was noted in 1995, while in 1992 Columbia was struck by a large piece of foam, ripping a 12cm gouge in the tiles. Both of these were before the switch to CFC-free foam.

Re:How long has this been happening?

[tgd]

But his overall point is quite correct -- every single shuttle mission came back with missing and damaged tiles.

Most of the shuttle is not under the same level of thermal load as the front edges of the wings during re-entry. Columbia got unlucky that the damage was at the worst possible spot.

Its a bad design, but the whole shuttle is an awful design. Most of the time it works, though.

IMO, this is a reaction to Columbia and a dramatically reduced interest in the shuttle program. For ten years launches barely got reported. Its nice (for the continuance of the shuttle program) for people to be talking about it.

Plus, for those who haven't seen a shuttle tile up close, they're not very big. Thats not a six inch gash in there.

Re:How long has this been happening?

[Hoi Polloi]

Or moving the tank up past the tail fin and protecting only vital areas such as the cabin. The windshield is already heavily reinforced to protect against small orbital debris. You have to think of unconventional alternatives sometimes.

Re:How long has this been happening?

[Moridineas]

Did you even read what you linked to?

Limbaugh says "there's a theory going around" and after explaining it says "a lot of people are beginning to think that the banning of Freon actually caused the shuttle accident, the Columbia shuttle accident, two flights ago. And I'm inclined to believe it when I hear this." This was on August 3rd, according to media matters. At this point the NASA report had not been released yet--it wouldn't be fully released for months! There was nothing to lie about!

Can someone really "lie" when they say "there's a theory I'm inclined to believe" ?

But I suppose it's just much easier to hysterically claim that Rush Limbaugh both originated the theory AND lied about it that to actually read your own link though!

Re:How long has this been happening?

[Hoi Polloi]

Seeing as they have figured out how to attach the braces without compromising the heat shields I would guess engineers could figure out a way to do it without eliminating the cargo bay.

Re:How long has this been happening?

[nahdude812]

Its a bad design, but the whole shuttle is an awful design.

Interesting perspective. Would you elaborate on what you would do differently that the hundreds of top-end engineers at NASA hadn't thought of? I'm guessing they want to know too.

Re:How long has this been happening?

[YrWrstNtmr]

Or moving the tank up past the tail fin and protecting only vital areas such as the cabin.

Again, you'd have to redesign the whole thing. The belly of the ship is like the frame on your car. The strongest part. You couldn't bolt the axles of your car to the roof, flip it over, and drive around. The roof would collapse. Similarly, you couldn't bolt the tank to the top skin of it, without major redesign.

The best way would be scrapping the side-by-side design altogether, and going with a stack. Which they are doing for the shuttle replacement vehicle. Like just about all previous designs. The delicate part (crew and cargo) is out in front of all the falling bits.

Re:How long has this been happening?

[j00r0m4nc3r]

I'm not saying I'm smarter than NASA scientists, but why don't they put some sort of protective layer on top of the tiles for launch, which later gets shed either in space or during re-entry?

Re:How long has this been happening?

[Hoi Polloi]

As you say, not worth the effort. Especially since the vehicle as a whole is so old that redesigning it would bring it forward many decades.

Re:How long has this been happening?

[tgd]

If you think that hundreds of engineers sitting down and designing it is how the Shuttle came into existance in the early 70's, you should go read up on some history of NASA.

The shuttle design (and the program) is one set of bad decisions after another made for corporate welfare and political reasons shoehorned through Congress based on a huge number of known lies (like the shuttle-launch-a-week they claimed they'd have). It was continued as a way of getting to the Space Station, even though the construction of it was delayed 15 years.

There were dramatically better designs considered during the 70s that would've been cheaper and more reliable, but wouldn't impact various Senator's home states as much. There were bad decisions made even after the Shuttle was picked (using aluminum skin not titanium, which is why the heat shield is needed anyway).

Seriously. Read some histories of the shuttle program. You'll learn why it happened and not the Apollo-based Mars mission, why the Saturn V (and future solid fuel boosted versions) were dropped in favor of a much more expensive per pound STS.

NASA has smart engineers. Thats why the design for the shuttle's replacement looks nothing like the shuttle. Its also a big reason why the Buran was killed in the USSR, and the Soviets/Russians dominated manned space flight for 25 years.

Re:How long has this been happening?

[iocat]

Dynasoar. I mean, Dynasoar. Neil Armstrong was chief test pilot before he bugged out for Apollo, and given his engineering background, he wouldn't have been on board if it wouldn't have worked. It was killed to concentrate resources on the nation's moon obsession (not that that's a bad thing, necessarily).

Re:How long has this been happening?

[icebrain]

It's more like the engineers got hamstrung by the Air Force and the beancounters. Original shuttle plans called for a fully-reuseable vehicle with a more robust thermal protection system. The beancounters promoted the half-disposable design we have now, claiming it would reduce costs, and contrived studies to show that it would be much more reliable than it actually turned out to be. They also screwed around with the budgeting, eventually causing even more cost overruns, delaying the development, and forcing compromises that made the vehicle less safe.

The Air Force wanted manned space capability, and offered to help pay for the development if they got some say in the design and were allowed use of the shuttles when built. The USAF insisted on a larger payload bay (60ft long, as opposed to NASA's 40ft plan), which obviously made the vehicle larger. They also wanted the ability to land at the launch site after a single polar orbit, requiring 1000+ miles of crossrange. This led to the heavier delta wing and higher reentry heating loads.

We wound up with a vehicle that was larger, more expensive, and less safe than we should have. The engineers did the best they could under the political mandates they were given.

Re:How long has this been happening?

[T-Bone-T]

Give the engineers better computers that they didn't have 30 years ago so they can create a much more sophisticated design?

Re:How long has this been happening?

[timeOday]

Maybe awesome for 1976 is awful for 2007.

Re:How long has this been happening?

[iocat]

Rush Linbaugh, inclined to believe an anti-EPA theory? I'm shocked, simply SHOCKED!

Re:How long has this been happening?

[emilng]

I really hope you're not a project manager or salesperson, though you sure sound like some that I've worked with before.
I would feel so sorry for the developers and engineers who would have to handle your projects.

"Why don't we create this project and give it a... I don't know... 2 week deadline, because summing it up in a sentence seemed easy enough"

Re:How long has this been happening?

[Anonymous Coward]

Because weight is a huge issue when launching a shuttle.

Re:How long has this been happening?

[Retric]

The problem with the shuttle is not any specific design decision it's the overall design goals which the "top-end engineers at NASA" had little to do with.

"The crucial factor in the size and shape of the Shuttle Orbiter was the requirement that it be able to accommodate the largest planned spy satellites, and have the cross-range recovery range to meet classified USAF mission's requirement for a one-around abort for a polar launch." The most obvious bad design decision was to send cargo up in a manned mission. Manned vehicles cost a lot more per pound sent to space than unmanned so mixing the two increases the cost of sending stuff to orbit with zero real gain. The other issue is the requirement for a polar orbit. (Think Russia) Getting people to space is hard but doable getting people to space and a polar orbit is a much harder task that is a waste of resources 99% of the time.

Second "Each Shuttle was designed for a projected lifespan of 100 launches or 10 years' operational life." However, Discovery was built in 1985 its last flight is scheduled for 2010.

If you want a cheep reusable rocket rebuild the shuttle with 5% its cargo capacity, a slow reentry, and skip the polar orbit concept and you get a much larger safety margin and a much less extreme operating environment and a lower cost per person to orbit.

Re:How long has this been happening?

[Gr8Apes]

The half-disposable design was a direct result of the military's insistence on increasing the payload carrying capacity by an order of magnitude combined with cutbacks in original funding targets. The increased size caused other design issues for re-entry and landing. It was also to have been replaced roughly 10 years ago.

Hence you have the bloated obsolete pig we use today.

Re:How long has this been happening?

[DreamCoder]

References? Oh wait, this isn't wikipedia...

Re:How long has this been happening?

[MarsDefenseMinister]

Both of the deadly shuttle accidents are directly attributable to the side-by-side nature of the orbiter and the fuel tanks and SRB's. This design should have been discarded. If the shuttle were stacked vertically, these particular failures would have been impossible.

Re:How long has this been happening?

[Anonymous Coward]

He certainly popularized that theory.

Re:How long has this been happening?

[jacksonj04]

On the subject of the cargo capacity - you do need some form of reusable vehicle with a large cargo hold.

A lot of stuff can be done with something like the ESA's ATV for supply delivery, or a similar automated 'barge' which could haul components to orbit for construction, and then use your proposed reusable rocket to get people up and down. Sounds good to me.

However, where the shuttle comes to the fore (And it's rare that it does) is having a flexible space which doesn't need a whole new launch vehicle to use. For example, entire science projects were bolted into the cargo bay and launched, and the shuttle is the only vehicle capable of recovery ie launching empty and carrying stuff back down.

I'll agree with you that of such a vehicle, only one or two are needed. TBH if an automated reusable bulk hauler can be developed, it would make life even easier still as then you can scrap the need for an integrated personnel/cargo vehicle and launch them separately, for return when convenient.

Or screw it all and build a space elevator.

Re:How long has this been happening?

[Ash Vince]

leftist crap You have one wierd idea of left wing politics if you actually believe that.

Does leftwing just mean anyone who is not a card carrying republican?

Re:How long has this been happening?

[Lumpy]

Hasnt the tile been redesigned for lighter weight? The white shuttle tile I have sitting on my desk is incredibly hard and I cant see even firing a high energy bullet at it doing that, It would pretty much explode. And yes it IS a shuttle tile, My brother back in the early 90's got me one when he was stationed at nasa for AirForce security on one of those "Sattelite? What sattelite? nothing to see here move along." missions. I keep it with my F-16 gun rounds on my desk to intimidate the Sales and Marketing people.

Re:How long has this been happening?

[FLAGGR]

A good start would be Richard Feynmans report on the challenger disaster (should be easy to get online.) He was no simple simon.

Re:How long has this been happening?

[Anonymous Coward]

where bullshit begets bullshit when posters hope that no one reads the fine print and instead spout hysterical leftist crap they hope everyone will just automatically believe

And that's different from Limbaugh because... oh wait, hysterical anti-EPA "theories" that have absolutely no basis in reality is hysterical rightist crap.

Re:How long has this been happening?

[Andrzej Sawicki]

Weight? Remember, this already is a protective layer. How many would you add to protect it (and those additional ones)?

Re:How long has this been happening?

[moosesocks]

Right on all accounts apart from the last one.

Buran was dropped due to a lack of funds because of the collapse of the Soviet Union, which left their space program strapped for cash.

Although Buran was essentially a copy of the Shuttle, the Soviet engineers were able to surmise its shortcomings and address those issues. For starters, it wasn't as vulnerable to the mess we had with Columbia, and are having again with Endeavour.

The crew compartment was supposedly reinforced and structurally isolated from the rest of the ship, suggesting that a Challenger or Columbia type disaster could have been potentially survivable.

Buran was launched piggybacked on an Energia booster (which is the closest thing Russia had to a Saturn V) -- economies of scale suggest that this would have been cheaper in the long-run, not to mention that it kept a large multi-purpose launch vehicle in Russia's "arsenal", something which the US currently lacks (not to mention that an Energia could have sent up huge portions of the ISS in one go, rather than expensively constructing it bit by bit as we are doing now.

Buran could fly and land automnously. The space shuttle gained this ability only recently, and to my knowledge, it's never been attempted. This combined with the continuation of the Soyuz program hypothetically allows the crew to stay aboard Mir/ISS, and return via a Soyuz capsule, while the Shuttle lands on its own in the case that it was damaged during takeoff, and would be risky to land.

I wouldn't be terribly surprised if NASA uses a similar strategy to get the crew of Endeavour home.

It still wasn't a great idea all in all, but it made a hell of a lot more sense than the Shuttle does. Kliper looks very promising at the moment, and may be a "best of both worlds" compromise between traditonal capsules and shuttle-type craft.

Re:How long has this been happening?

[mgabrys_sf]

re:"The crew compartment was supposedly reinforced and structurally isolated from the rest of the ship, suggesting that a Challenger or Columbia type disaster could have been potentially survivable."

The crew compartment on the Challenger broke away and tumbled all the way down with many of the crew members still alive but unconcious. It's the part where it slammed into the ocean that killed everyone. Was the BURAN crew component outfitted with parachutes?

Re:How long has this been happening?

[fremsley471]

One word: Vandenberg. The 1000 miles range was necessary as the Air Force were s'posed to want to launch on the West Coast and that would leave the Shuttle over the Pacific with the next polar orbit and emergency landing opportunity. The lifting body (Dynasoar) plans were dead with this simple, and completely unfulfilled, decision.

Re:How long has this been happening?

[Lord Ender]

A more important question would be: Did Limbaugh issue a correction once the report was published? If he did not, he is clearly trying to intentionally mislead his listeners. This is only slightly different from lying, and is deserving of harsh criticism.

Re:How long has this been happening?

[The_Wilschon]

Unless you're the usual slashdot fuck - in which case - please die painfully, and nice and slow. Perhaps a fire, or a slow crushing. Fire ants are good to. Try to work them in somehow. Was this necessary? If I had modpoints right now....

Re:How long has this been happening?

[FLAGGR]

Wow, angry much?

Richard Feynmans report was pushed into the appendicies of the full report. Personally, I don't think it is dry, but to each his own.

Re:How long has this been happening?

[Lumpy]

and all of you need to say Thank you for that.

Hubble would have been far less effective if it was smaller, or simply not built if it had to be launched on a huge rocket or assembled in space.

Honestly the larger size fothe Shuttle has enabled far more missions than were thought possible.

Re:How long has this been happening?

[Anonymous Coward]

Limbaugh says "there's a theory going around" and after explaining it says "a lot of people are beginning to think that the banning of Freon actually caused the shuttle accident, the Columbia shuttle accident, two flights ago. And I'm inclined to believe it when I hear this." This was on August 3rd, according to media matters. At this point the NASA report had not been released yet--it wouldn't be fully released for months! There was nothing to lie about!

The problem with this is that there's so much "nudge-nudge, wink-wink" that goes on, that what is being communicated amounts to much more than what is literally being said. Rush knows what's being communicated, and doesn't stop anyone from drawing the conclusions that are implied. It's not like he made it clear that there might be alternative explanations for what's going on, and that we should hold off on drawing conclusions.

So maybe Rush is a frickin idiot who doesn't do his fricking research, and shouldn't be listened to, and people who listen to him are fricking idiots for doing so. Maybe this isn't technically a lie. But it is pretty clear that either (1) he is strongly implying that something is the outcome, not quite a misrepresentation but close to it, or (2) he is irresponsible and incompetent as a journalistic professional, or (3) both.

By the way, this isn't to pick on Rush in particular. I think this could happen with any commentator of any political persuasion. But one of the biggest problems with heavily politically biased media--currently generally conservative--is that this bias is unspoken and unacknowledged. Things are presented as being "fair and balanced" when they are far from it, without this being openly acknowledged. This is the "lie" that implicitly underlies all of this, and becomes instantiated in various ways, including Rush's discussion of Freon.

Re:How long has this been happening?

[Anonymous Coward]

Additionally, an extra protective layer also becomes a hazard when it comes off.

Re:How long has this been happening?

[Retric]

you do need some form of reusable vehicle with a large cargo hold.

Why? Generally speaking the important thing is cost per LB to orbit. Let's say you can move 20tuns of cargo to LEO at 1k / LB and a 90% success rate or 5k/LB at 95% success rate or 10k/LB at 98% success rate. Well the real cost of LEO of the first system is 1.1k/lb + 10% the value of the cargo which in the vast majority of unmanned systems is a lot cheaper than ~5k/lb to LEO we have today.

The real reason space is expensive is we don't send much stuff up. The real reason we don't send much stuff is we don't need a lot of junk in orbit. We already have GPS, Weather Satellites, Spy satellites, telescopes, telecommunication gear, etc but other than replacing what's every few years what's the next stage? Let's say you now have the capability to send 50,000 tons to orbit for 100$/lb what new things would you place up there?

PS: I can see the value of returning say 100 lb of samples from orbit but what could be worth spending millions returning from orbit that you can't just build here?

Re:How long has this been happening?

[nova96]

Buran could fly and land automnously. The space shuttle gained this ability only recently, and to my knowledge, it's never been attempted

One of my college professors actually worked on the guidance, navigation and control system for the shuttle program. From my conversations with him, the shuttle has always had an autoland capability, it was just the fact that none of the hot shot shuttle pilots wanted to be the first to not land manually.

Re:How long has this been happening?

[spasm]

Actually giving a shit about Rush Whatsisname's idiot opinions has the unfortunate effect of causing people to repeat those opinions in forums other than the US AM radio spectrum, if only to refute them, which means far far more people hear Rush's moronic ideas than would have otherwise been the case. If you want Rush to go away, don't listen to him and certainly don't *ever* repeat anything he said in another forum.

Re:How long has this been happening?

[geobeck]

...damage, either ice or micrometers.

Damn those scientists, out there poking the shuttle with their micrometers!

Re:How long has this been happening?

[kimvette]

It may have been a problem all along, but there has been a lot of wear and tear on the airframes. I'm sure that the fatigued has changed heat handling characteristics at stress points, and that can feasibly contribute to failure where tiles may be thin, broken, or otherwise faulty, whereas if the airframes were new or treated to restore its original integrity the heat handling characteristics would not be an unknown.

Just pointing out a possibility I haven't seen anyone in the media question. . .

Re:How long has this been happening?

[icebrain]

Hubble is believed to be based on the same "chassis" as the contemporary US spy satellites (KH-11, I think). Those were launched on the larger Titan vehicles, and Hubble could have been as well, had the choice of launch vehicle not been dictated politically. US policy up until Challenger dictated that all US satellite launches (including commercial ones) would shift to the shuttle, in an attempt to justify the program and boost the flight rate closer to that originally projected, and so Hubble was adapted specifically for shuttle launch. After the accident, the policy was changed to only allow payloads that required the shuttle's capabilities. Hubble was too far along to be modified for conventional rocket launch (because the payload mounts in the shuttle bay transfer the loads differently than a conventional mount), so it remained as a shuttle payload, as did the Galileo, Megellan, and Ulysses probes.

It's true that the shuttle made subsequent repair missions easier. But to say that only the shuttle could have launched the missions listed above isn't.

Re:How long has this been happening?

[belunar]

You realy cant count the Enterprise in this, it was a test orbiter that never left the atmosphere.

http://science.ksc.nasa.gov/shuttle/resources/orbi ters/enterprise.html "Following in the Enterprise's, the orbiter Columbia was created and it became the first Space Shuttle to fly into Earth orbit in 1981. "

When looking at missing/damaged tiles, the only shuttles that can be considered are the ones that acualy had to go through the ordeal of launch, reentry, and landing.

Tiles have gone missing during launch from the shuttle before and landed ok. The Columbia disaster happened due to the damage of the wing beyond the tiles. There was litteraly a hole in the leading edge of the wing.

Another thing to keep in mind is these tiles, while able to withstand great heat, are also fragile. http://science.ksc.nasa.gov/shuttle/technology/sts -newsref/sts_sys.html#sts-hrsi

I would be more worried finding the skin under the tile was damaged than finding the tiles were damaged. I think this is more PR of them showing they are trying to keep it safe and reactionary journalism than an acual problem.

With that said, I also reserve the right to be wrong.

Re:How long has this been happening?

[MarsDefenseMinister]

That's pretty much what I said WRT Enterprise.

And I agree that this damage isn't much to worry about. The structures underneath this particular section can actually take the heat if the skin is penetrated.

Re:How long has this been happening?

[Polar Star]

His point was correct. I think you were a little harsh. http://science.ksc.nasa.gov/shuttle/missions/sts-1 /mission-sts-1.html The first space shuttle Columbia STS-1 went up in 1981 and came back with 16 tiles lost and 148 damaged.

Re:How long has this been happening?

[Anonymous Coward]

Why is a dumb question Flamebait?

Re:How long has this been happening?

[rpbird]

You are correct sir! (Phil Hartman SNL flashback - god I miss that guy). I remember a few of the preliminary designs made public back then (I knew my old age would come in handy someday). There were several piggyback models using a liquid-fueled lift vehicle that, if one of them had been adopted, would have prevented both shuttle crashes. There were also follow-on heat protection schemes that never saw the light of day, like replacing the tiles with a "carbon-carbon blanket." Just the snafus involved in developing the shuttle's main engines could fill a book, because they used a "hurry-up" approach that ignored decades of sound development practices.

Re:How long has this been happening?

[Naito]

No, I'm afraid you're wrong. Columbia was lost about a third of it's tiles during delivery from Palmdale to KSC. That was probably the only time there was such severe tile LOSS.

During it's first flight Columbia came back from STS-1 with a large number of tiles missing, blown off due to shockwaves during launch, there are fairly famous pictures of large sections of tile missing on the OMS pods taken from within the orbiter while it was in space.

The most significant tile damage was on an Atlantis DOD flight, I forget the flight number, there were entire tiles missing and a huge number were damaged, visible pitting from the chase plane, so far far more severe than the current Endeavour damage.

Enterprise didn't even have tiles, it was all mockup panels.

I think you need to give hime your geek card =D

Re:How long has this been happening?

[Sir Holo]

but why don't they put some sort of protective layer on top of the tiles for launch, which later gets shed...?

Well, then they would need a protective coating for that protective layer.

Then it might be necessary to put a shielding layer over that, and finally maybe shrink-wrap over the whole thing, just to "keep it nice."

Re:How long has this been happening?

[jafac]

Yes;
The Air Force bears much of the blame.

They wanted to be able to launch NRO payloads, and with the Keyhole platform, that meant the larger cargo bay, and "high-inclination" orbits, (ie. Vandenberg. . . ie "cross-range capability"). Well, Thiokol never delivered on the SRB's that would have given the cross-range capability, so that was the first thing to get shitcanned. So the Air Force was already screwed there, and for much of the 1980's could not launch NRO payloads into high-inclination orbits.

Then Challenger happened, and the Air Force whined to congress - because now they couldn't launch NRO payloads AT ALL. So they got the EELV program (Atlas/Titan/Delta - where Atlas and Titan were mainly recycled ICBM's - and now, Atlas is a totally new platform based on the old design.) - after that, the Shuttle really needed a new purpose in life, and got one, in the way of the ISS. Say what you will about it - I'm not a big fan of it myself - I think it shows a lack of vision, and was really driven as a means of pork-continuation. Though, we did learn a lot about international collaboration on a really huge, really complex project. That has to be worth something.

In the aftermath of Columbia - I'm not sure that recycling Shuttle technology and hardware is the best approach to getting a new generation of launch vehicles. But given the likely funding profiles, who knows if even THAT will succeed?

Re:How long has this been happening?

[jafac]

The Vandenberg capability was based on Thiokol being able to deliver a more powerful SRB. They failed. That's why they built a launch facility, hell, even a VAB, and a widened road to haul the shuttle from the airstrip to the VAB, and they built an SRB reprocessing facility, including a new pier for the recovery ship.

Vandenberg was ramped up to process Shuttle flights - they previously didn't even have ANY manned spaceflight capability at all. They built all that out. And Thiokol blew it.

Re:How long has this been happening?

[jafac]

I thought that it would be good to have the foam on the tank shed right at launch - maybe attached to the ground by cables.

that way, the foam (and ice) never gets to a high velocity, and there's an immediate weight savings.

SpaceX does this with A thermal blanket that sheds on liftoff.
(unfortunately, the thing did get hung-up on the ill-fated first launch. Mr. Musk assures us that it had nothing to do with the crash, however).

Re:How long has this been happening?

[Mr. Slippery]

Can someone really "lie" when they say "there's a theory I'm inclined to believe"?

Gee, I don't know. If I were to say, "There's a theory I'm inclined to believe that Moridineas sodomizes puppies by the light of burning American flags", would I really be "lying"? Would I be lying if I said "a lot of people" beleived it?

If I wrote that as a serious allegation, you'd probably sue me for libel, and IMHO have a strong case. (Let me be clear: I have no knowledge that Moridineas engages in any cruelty to animals, or burns anything.)

This was on August 3rd, according to media matters. At this point the NASA report had not been released yet--it wouldn't be fully released for months!

Note the date on the page. This is August 3, 2005; Media Matters is calling him on it only a few days later. The Columbia Accident Investigation Board released its report in 2003.

Re:How long has this been happening?

[coaxial]

Heh. Turn in your geek card. This also occured on STS-1.

http://history.nasa.gov/sts25th/history.html :

Though the payload bay doors were opened without incident, their successful operation provided a clear view of the craft's Orbital Maneuvering System (OMS) pods, which showed signs of heat-shield tile damage. Mission Control counted 15 tiles missing from the OMS pods, which contained the vehicles in-orbit thrusters. Houston determined that the missing tiles would not present any problem, but mission controllers did not know if there was extensive tile damage on the orbiter's underside, an area more sensitive to reentry heating.

http://www.nasa.gov/mission_pages/shuttle/shuttlem issions/archives/sts-1.html :

Major systems tested successfully on first flight of Space Transportation System. Orbiter sustained tile damage on launch and from overpressure wave created by the solid rocket boosters. Subsequent modifications to the water sound suppression system eliminated the problem. A total of sixteen tiles were lost and 148 tiles were damaged.

And of course the photographic evidence. It's a famous photo. Which led to speculation of a "zipper effect," where if a hole developed in the tile protection system, that all the other tiles would be ripped off.

Tile loss was incredibly common on the shuttle through out the early missions. We're talking through at least 86. It wasn't whether tiles were going to comeoff, but how many and where? They never came off in sufficenent numbers to cause extensive damage, nor in any places that endagered the orbiter, but they came off all the time.

Re:How long has this been happening?

[petermgreen]

This kind of damage MUST have been occurring throughout the history of the program. And, if it has been NASA would have been aware during the regular retiling of the Shuttle. My question is why wasn't the ice impact problem wasn't addressed long ago.
because the craft survived so the condition of the tiles was obviously sufficiantly good.

the REAL problem is there haven't been enough shuttle crashes to get decent data because of the relatively small total number of shuttle flights and no other spacecraft in service is anything like the shuttle in design.

You can't have large safety margins on everything on a spacecraft because if you did it would never fly so you have to judge what is important and what isn't. One source of such information is past accidents but with the total flight/accident count so low (iirc it is two fatal accidents on two hundred and something missions) this is far from accurate.

The reason the chance of dieing on a modern plane flight or train journey is so low is because there have been sufficiant accidents in the past to have good statistical information on what components are likely to fail in a catastrophic way and therefore need to be overengineered, have backup systems or at least be inspected regularlly.

Re:How long has this been happening?

[AK Marc]

Can someone really "lie" when they say "there's a theory I'm inclined to believe" ?

Yes. He's "inclined to believe" because he doesn't believe. He doesn't believe because there are no facts to support the conclusion. The official report, released before his statements, directly contradicts the anti-environmentalists. Rush takes the "environmentalists killed honorable astronauts" stance because that's the entertainment that he's paid to provide. And yes, he is an entertainer and nothing else, no different from a stand-up comedian, other than he doesn't stand up often. But he says things that he knows to be false, or he says things in a manner designed to mislead. Either way, he's a liar. There are many books on that subject. Even at least one with that title.

Re:How long has this been happening?

[Anonymous Coward]

The little known fact is that there is barely any difference between the ozone depleting effects of chlorofluorocarbons and hydrochlorofluorocarbons. Both will form free radicals in the upper atmosphere that will produce a chain reaction of ozone degradation of ~50000:1 ozone:cfc/hcfc.

Essentially any halogenated hydrocarbon will have the same effect, rgardless of the degree of halogenation. But hey, what do chemists know? Obviously politicians and environmentalists know everything!

I am an environmentalist myself (though not active or militant) and I have already given up on the future of humanity on earth. Knowing what I know as a chemist I know that there is no sense in fighting it, it is a lost cause, we are way past the point of no return. So future generations be damned, I have no kids myself and would prefer to keep my sanity than to fight for a lost cause.

Re:How long has this been happening?

[iamlucky13]

There is no solution that wins across the board because each design has different strengths and weaknesses.

Buran was generally similar to the shuttle, and yes it did have some similar vulnerabilities as a result. The payload sits in a side-stack configuration, leaving it exposed to potential debris (no foam, but possibly ice) falling off the core stage or a core stage explosion. Also, their hypergolic fuel was very corrosive and more of an explosive hazard on the pad (as evidenced by the SS-18 program) than the SRB's on ours.

Other architectures aren't unilaterally better. They're better by specific criteria...and worse by others. Some of the advantages of the shuttle is that it's a versatile work platform (performed 3 Hubble service missions), it can return large cargos from orbit (multiple spacelab missions and a few satellite retrievals), it doesn't require a separate launch and rendezvous for missions requiring cargo and crew together, and it has much more control during landing. Only the SST and the Buran have/had these capabilities. Even the Kliper, if it ever does get built, will only have a similarly controlled landing. NASA has had several similar proposals, but none got funding.

It's hard to fairly compare the Soyuz or other capsules to the shuttle for these reasons. Heck, an entire Soyuz (actually, two of them by mass, but together they would be too long) with its 3 man crew could be lofted by the shuttle...along with it's own 7 crew.

The Space Shuttle's inability to be landed remotely was actually a safety feature reflecting the intent to only launch it manned. Since the landing gear can not be retracted in flight (same for the Buran, as far as I know), the controls for lowering them are operated manually so a computer bug can not trigger them. The "upgrade" to allow automatic control was a cable that connects the computer to the landing gear relays. Lastly, I want to note that launching larger segments of the station by Energia would not be trivial due to their modular nature. Of course, this is partially a result of function but largely a result of their being designed around available launchers.

Re:How long has this been happening?

[Moridineas]

The official report, released before his statements, directly contradicts the anti-environmentalists. This is a theory that originates from one of AK Marc's LIES.

Get your facts straight, or at least if you can't do that, READ MY POST--the report was released almost a month later according to Wikipedia--August 26.

I do not understand the sheer hypocrisy you exhibit here. You go ballistic someone you disagree with you has intentionally lied, all the while spreading further lies (by your standard of lie) yourself!

Re:How long has this been happening?

[dbIII]

The bit that I really cannot understand of the design is why the shuttle is attached to the side of some enormous rockets instead of on top. The bending moment must be huge and the aerodynamics of getting such a structure into the air complex.

Re:How long has this been happening?

[dbIII]

It has its origin in one of Rush Limbaugh's lies.

Surely he wouldn't lie about how people died just to say bad things about environmentalists? Oh, he does that sort of thing does he? That would utter contempt for those that died. Funny how people who wrap themselves up in the flag at any opporunity are those that would use it to polish their shoes to make themselves look better.

Re:How long has this been happening?

[Phaedra]

Just a small correction. According to my copy of "Rockets of the World" by Peter Alway and http://www.astronautix.com/lvs/energia.htm and http://www.buran-energia.com/energia/energia-desc. php, Energia used LOX/Kerosene strap on boosters and a LOX/LH2 core. No toxic, hypergolic fuels (though they were considered early in the design).

Re:How long has this been happening?

[shadowbearer]

I've read the published book on the challenger disaster. It's about as dry as the Ken Starr report.
 

 

  What, did you expect it to be entertaining? You don't expand on your principal bit of evidence, much.

SB

Re:How long has this been happening?

[shadowbearer]

  Not to mention the decades and money we spent on making vertical stacks work. Then we mothballed them.

  Most definitely NOT intelligent design ;)

SB

Re:How long has this been happening?

[Gr8Apes]

Rockets can carry larger payloads than the Shuttle. The new Delta can carry over 50K pounds, about the same as the Space Shuttle. Compare that to the Saturn V's 106,000 pounds.

So no, the Hubble could have been launched on another platform. As for the repair, that could have been done with the original shuttle design, as they certainly didn't carry a 50K payload for repairs.

Re:How long has this been happening?

[mgabrys_sf]

Development of entire program as mentioned by the non-responder full-of-shit parent, not one incident fucktard.

As for writing - reports don't even qualify as GOOD WRITING fucktard version 2.0. I'd like oh - I don't know - something that smacks of reportage. Not tax-code filings.

Re:How long has this been happening?

[Anonymous Coward]

Hmm...thanks. Looks like wikipedia probably needs updating. It doesn't actually say hypergolic, but it does say toxic, explosive, and refers to the SS-18, which is hypergolic-propelled.

Your book there doesn't happen to say how they deal with the cold fuel without any foam, does it? Maybe a double walled tank? I can't imagine they are able to just ignore the ice and boiling issues.

Re:How long has this been happening?

[splutty]

The main engines of the shuttle itself provide both extra steering capabilities as extra lift power. The enormous tank the shuttle is mounted on is the actual fuel tank for the shuttle's main engines.

Re:How long has this been happening?

[dmhayden]

But his overall point is quite correct -- every single shuttle mission came back with missing and damaged tiles.

Every mission except the one that didn't make it back.... Damaged tiles are potentially fatal, so they're trying to fix them. That makes sense to me.

Re:How long has this been happening?

[Anonymous Coward]

The phrase "order of magnitude" means a tenfold increase. Increasing the size of the cargo space by 40 feet to 60 feet is a far cry from increasing it from 40 feet to 400 feet.

Re:How long has this been happening?

[zerkon]

By NRO do you mean the National Reconnaissance Office? Which I don't think has anything to do with the AF right? (I don't really know but I am curious)

Re:How long has this been happening?

[eh2o]

Disputing use of the word "lie" is just semantic bickering, it dodges the real issue over what he said.

Consider this; a rumor is "going around", and there is absolutely *zero* factual evidence to support it (and, absurdly enough, later investigation finds the exact converse to be true), and yet he is "inclined to believe" that it is true. Interesting, that. Inclined to believe on what basis? Was this rumor leaked from a secret source inside NASA that he trusts? Nope, its just "going around".

Ultimately he doesn't say what his reason is, but it is implied in the subtext if you read carefully -- if the rumor were true it would make the EPA look "stupid" for having banned freon. Limbaugh is "inclined to believe" the rumor because it supports his position on the EPA.

Now technically he didn't lie about anything, and no one is going to jail for being "inclined to believe" a baseless assertion. On the other hand, we can hardly award him for his outstanding journalism. Just like all the other loose nuts his approach to fact-finding is totally anti-scientific. His conclusion on the EPA is foregone; he does no real investigation, and no fact-checking -- he simply trumpets anything he can find that supports his theory. I don't care if his theory about the EPA is right or wrong because even if he is right, it is by coincidence alone as his methods are so flawed as to make his entire effort meaningless.

Re:How long has this been happening?

[guardian-ct]

Incredibly hard, yes. Unbreakable, no. I suspect if you actually shot that tile with a bullet, the tile would fracture. According to what I've read about the tiles, they're very good at protecting from heat, very hard, and very light. Materials with those characteristics (in the 1970-80s) are also very brittle.

For more information, including how to figure out which tile you have:
http://www-pao.ksc.nasa.gov/kscpao/nasafact/tps.ht m

Endeavour:

[kaleco]

"it's just a flesh wound"

Re:Endeavour:

[superstick58]

"I've had worse!"

Re:Endeavour:

[ashitaka]

"No it isn't!, Your wings come off!"

Riding the TGV to hell.

Re:Endeavour:

[solitas]

Here are the first hi-resolution shots of the damage and some cool ones of the station and shuttle and miscellaneous:
    http://www.nasa.gov/mission_pages/shuttle/shuttlem issions/sts118/multimedia/fd3/Image_Gallery_Collec tion_archive_3.html (page 3 at time of posting).

Err on the side of caution...don't you think?

[TripMaster Monkey]

On NPR this morning, I heard that NASA was actually debating whether or not to even address this, as they did not want to go to all the trouble and spoil the shuttle's schedule.

This sounded especially insane to me...if NASA loses another shuttle because of this same tile-damage problem, and because they couldn't be bothered to take the time to fix the problem when they could have, it will be the end of NASA.

Re:Err on the side of caution...don't you think?

[datan]

maybe we should leave the rocket scientist stuff to real rocket scientists...

Re:Err on the side of caution...don't you think?

[grommit]

You do realize that the Shuttle has landed many times before the Columbia disaster with whole tiles missing. This most likely is a non-issue although I'm glad NASA is treating it seriously. Besides, these tiles are on the belly of the orbiter. The damaged RCC panels on Columbia were on the leading edge of a wing where there are greater temperatures on reentry.

I don't think you realize the inherent danger in attempting to fix these either.

Re:Err on the side of caution...don't you think?

[Anonymous Coward]

They could lose an astronaut doing the EVA to fix this. There are trade offs involved here and you don't seem to know any of them.

Re:Err on the side of caution...don't you think?

[balthan]

That worked so well for Columbia.

Re:Err on the side of caution...don't you think?

[russ1337]

>>>... maybe we should leave the rocket scientist stuff to real rocket scientists...

I dunno. I think the Slashdot crowd would make for interesting space program management.

Couldn't be much worse....

Re:Err on the side of caution...don't you think?

[TripMaster Monkey]

They could have lost astronauts during the EVA to fix the Hubble, but they went and fixed it just the same.

So, are you saying preventative maintenance to help raise the odds of all the astronauts coming home safely is less important than a telescope?

Re:Err on the side of caution...don't you think?

[Anonymous Coward]

It always amuses me how the masses sitting on the sidelines always feel they can do better then the trained professionals. I'm assuming you've already done the calculations between risk of the loss of them doing a spacewalk vs tile damage, where the tile is positioned, and taken into account the fact before Columbia that tiles fell off without incident. I could be wrong, but I'm just as qualified as you are. So is the guy I bought a hotdog from yesturday for that matter.

This would be like my mom telling me she can do computer support better then me. She's a smart lady, but her KNOWLEDGE level when it comes to Computers is low.

Re:Err on the side of caution...don't you think?

[Anonymous Coward]

The previous shuttles all had similar tile damage and in most cases it was significantly worse. Columbia had a tile problem on the wing tip which is why it broke up during reentry. Under the belly of the shuttle is a safer place for the damage in this regard.

Re:Err on the side of caution...don't you think?

[Anonymous Coward]

So, are you saying preventative maintenance to help raise the odds of all the astronauts coming home safely is less important than a telescope?

While many of us Terrans would say 'no', I'm sure most of the astronauts would actually answer 'yes'.

Re:Err on the side of caution...don't you think?

[everphilski]

They are in the wind tunnel doing test studies on a similar gouge crafted from the laser data taken on Monday. The Shuttle people know what they are doing. You have to remember, this gouge was downgraded from the size stated earlier this week, its only about the size of a business card, half the size that was being reported on Monday and less a quarter of the size that was thought to have dealt Columbia in.

You also have to consider position. This is at the very rear of the vehicle. Reentry heating evironments are most severe near the stagnation point at the front of the vehicle. Towards the back you can actually get some recirculation that provides some cooling. It may not be worth the risk/reward to go and patch it, based on locale. I guarantee you if this was on the front of the orbiter, it would be a whole different story.

Re:Err on the side of caution...don't you think?

[couchslug]

"it will be the end of NASA."

Good. Space exploration is more important than a few casualties. If we must lose a Shuttle to dump that idiotic program, than that's what it takes. It's time we got rid of the desire to shove humans out in front of unmanned systems, but people are stupid so it may take a bloody nose.

NASA can turn into something else, because the people running it have the wrong priorities.
We don't need meat in space right now because it is a drag on techno-evolution.
Manned systems must have slow development cycles which cripples their ability to evolve quickly. We can RAPIDLY improve unmanned systems, evolve technology quickly, then entertain ourselves with meat in space at leisure.
If we were results-oriented instead of entertainment-oriented we'd go slower and as a result, get there with quality systems.

Re:Err on the side of caution...don't you think?

[Anonymous Coward]

You missed why the NASA folks thought it might be a good idea to skip the repairs.

"as they did not want to go to all the trouble and spoil the shuttle's schedule"

Re:Err on the side of caution...don't you think?

[YGingras]

Can't they plug the hole with some kind of high-tech epoxy goo? I'm sure that avoiding the extra air turbulence that this hole will generate can't hurt.

Re:Err on the side of caution...don't you think?

[pragma_x]

I think the Slashdot crowd would make for interesting space program management.

Poll: Preferred Shuttle Heat-Shield Repair Technology

• NASA developed tile repair goo
• Spare heat-shield tiles
• Switch to ablative shielding instead
• Inanimate carbon rod
• Modulated tachyon pulse
• Whatever Cowboy Neil had for lunch

Re:Err on the side of caution...don't you think?

[catbutt]

I'm sure they have consistant ways of calculating costs vs benefits vs safety, that are better than your simplistic, knee-jerk intuition.

If we viewed it as all black and white, and safety trumped everything, we'd never go into space, right? But even if only calculating safety, it may well be that in this case, the best decision is to not fix it. Since this has happened many times before on the shuttle belly, they've done the math, and they have calculated that the risk is minimal to non-existant. Meanwhile the risk of an EVA is greater.

But apparently you've made more a accurate risk-assessment based on eyeballing some photos?

Re:Err on the side of caution...don't you think?

[Stormcrow309]

As a trained project manager,I have to take issue with this statement. I do think that NASA suffers from management who makes risk calculations with too much consideration of 'the schedule' verses the risk of life. However, NASA has done a valid risk mitigation step by examining the shuttle after takeoff and trying to determine what to do. Most sensible people can do the risk management required by asking a few questions. What is the risks? What are the chance of those risks being realized? How can we mitigate those risks? Those analysis steps are done by engineers, but it comes down to the manager who has to give the go/no-go decision. 10% risk of catastrophic failure? Ok, what are the other options?

Stuff like this requires more significant then six sigma quality (3.4 defects per million). The CMS puts a 0% error rate requirement on certain measures for hospital quality. Does someone presenting heart attack symptoms get an aspirin within the first 24 hours of being in a hospital? Do they get a beta blocker within 24 hours? 0 variations are allowed to meet their quality goal. Six sigma level quality would have 1 variance out of large hospital's annual patient level of patients presenting heart attach symptoms, which is unacceptable by the standard. Set a risk measure and goal for shuttle tiles, for example - 0% risk of a tile related catastrophic failure upon re-entry. Then make the engineers plan for how they will achieve it. If the engineers fail at achieving this, causing a catastrophic failure, start license removal procedures on the engineer that signed off on it, followed by criminal charges.

Re:Err on the side of caution...don't you think?

[markov_chain]

it will be the end of NASA.

Or the end of the space shuttle, which wouldn't be such a bad thing.

Re:Err on the side of caution...don't you think?

[ChrisA90278]

"I heard that NASA was actually debating whether or not to even address this,"

There is some small risk if it is left un-repaired but. But a reapair carries considerable risk (1) Simply going outside puts the astronaut at risk of all kinds possible accidents. (2) The repair attempt could go wrong and cause more damage (3) the repair method is untested and may not even work

Way risk the above if they know that many shuttles have landed with this type of damage and not had problems.

That said one reason to try it is to test the repair technique.

Re:Err on the side of caution...don't you think?

[jc42]

Can't they plug the hole with some kind of high-tech epoxy goo?

There have already been a few cartoons published showing a couple of guys in space suits next to the shuttle, unwinding a big roll of duct tape.

Re:Err on the side of caution...don't you think?

[Goaway]

Maybe, you know, just maybe, it's not a good idea to stuff crap that will expand and burn in the cracks between the heat shield tiles?

Re:Err on the side of caution...don't you think?

[jafac]

I still feel strongly that they should attempt a repair, in this case.

First and foremost - if there is a small chance of catastrophic loss of vehicle, then measures should be taken to prevent that.

But Secondly - and possibly more importantly; how many more shuttle flights will there be? What if there is more serious damage on the next flight? And we still have never tested the repair techniques?

I think that this damage is a perfect opportunity for NASA to do what it does best: testing new aerospace technologies - and in this case, repair of shuttle heat-shield damage. The repair job will be a great opportunity to learn new EVA skills and techniques. After the shuttle is safely down, the repair job can be studied, and evaluated for how it held up during re-entry, and I think that is valuable science that wouldn't otherwise be done.

To *not* repair this damage, is short-sighted in two ways: It's hoping that the damage to Endeavor isn't fatal, and it's hoping that the next mission to get damaged, also does not require repairs, and if it does, that we will get the repair right the first time, when we've never ever done anything remotely like it before.

Re:Err on the side of caution...don't you think?

[Anonymous Coward]

They could have lost astronauts during the EVA to fix the Hubble, but they went and fixed it just the same. So, are you saying preventative maintenance to help raise the odds of all the astronauts coming home safely is less important than a telescope?

I have never seen a finer example of a strawman argument than this.

Re:Err on the side of caution...don't you think?

[ashitaka]

End of space shuttle = end of ISS.

Russia doesn't have the resources to maintain, stock and continually orbit boost the ISS. Maybe they should boost it to a higher orbit once the Shuttle's orbit altitude limitation is no longer an issue.

Re:Err on the side of caution...don't you think?

[Toonol]

Set a risk measure and goal for shuttle tiles, for example - 0% risk of a tile related catastrophic failure upon re-entry. Then make the engineers plan for how they will achieve it. If the engineers fail at achieving this, causing a catastrophic failure, start license removal procedures on the engineer that signed off on it, followed by criminal charges.

That's blatantly ridiculous for a number of reasons obvious to any reader. In fact, any engineer that signs off on a statement that there's a 0% chance of risk is incompetent. (Although, maybe he'll get promoted to project manager that way...)

Re:Err on the side of caution...don't you think?

[amokk]

Why would you bother explaining this to him? I bet you he's one of those people who goes on the internet, calls other people 'sheeple' and immediately starts posting pseudo-intellectual discussion on any forum/blog that would have him. He will not be able to understand the concept that NASA isn't run by a bunch of idiots and that people who know what they are doing have already taken all of his useless observations into account and dismissed them.

We can only hope that nothing that is remotely important in this world will ever be touched by a slashdotter.

Re:Err on the side of caution...don't you think?

[Richard W.M. Jones]

I think that this damage is a perfect opportunity for NASA to do what it does best: testing new aerospace technologies - and in this case, repair of shuttle heat-shield damage. The repair job will be a great opportunity to learn new EVA skills and techniques. After the shuttle is safely down, the repair job can be studied, and evaluated for how it held up during re-entry, and I think that is valuable science that wouldn't otherwise be done.

The problem is that the repair itself is likely to cause loss of vehicle. The tiles are incredibly delicate, and an astronaut housed in a bulky, heavy spacesuit, mounted on the end of a remote-controlled arm in weightlessness of space, does not have fine, careful control. He (or she) might easily put a boot or shoulder into the other tiles, resulting in even worse damage.

Rich.

Re:Err on the side of caution...don't you think?

[tftp]

(1) Simply going outside puts the astronaut at risk of all kinds possible accidents.

Then he has a wrong job. Astronaut's work is to fly the spacecraft and do spacewalks. It's risky, but otherwise why do we even bother to send them up?

(2) The repair attempt could go wrong and cause more damage

The repair can be attempted on a test set of tiles, pre-damaged in various ways and not needed for the landing (such as tiles for this test glued to non-critical or already protected areas.)

(3) the repair method is untested and may not even work

This is equivalent to your (2), namely that the repair may go wrong. The technique should have been safely tested. But now NASA may need to test on a live setup, where failures are dangerous.

Re:Err on the side of caution...don't you think?

[GodfatherofSoul]

This is what happens when you hire people to "run NASA like a business." Corporate Dilberts cut corners to save costs and cut time. Scientists and engineers don't (and shouldn't) operate with that mentality.

Re:Err on the side of caution...don't you think?

[Wormholio]

You do realize that the Shuttle has landed many times before the Columbia disaster with whole tiles missing...

I don't think you realize the inherent danger in attempting to fix these either.

While they are now minimizing the supposed danger of the damage, they may also be passing up an opportunity. Several methods have been worked out to try to repair damaged tiles. They could try one of these, to see how well it works.

Also, while the damage now seems to not be life-threatening, leaving the broken tile the way it is would likely lead to more extensive repair and refitting when it's back on the ground.

This of course has to be weighed against the risk of the repair EVA, and the resources available (air, water, fuel, food) for extending the mission for this. The fact that the shuttle can now get take power from the ISS helps somewhat in this regard, but someone who knows far more than me about the details has to balance all the the pros vs the cons.

Re:Err on the side of caution...don't you think?

[mozzis]

I think that, given the design we have, the easiest way to address this problem would be to make it less dangerous to do the repairs. Why is it so inherently risky to do an EVA? What changes to equipment and/or procedures would make EVA safer?

Re:Err on the side of caution...don't you think?

[Stormcrow309]

0% was a toss-out number, until you are on the variation shuttle.

Re:Err on the side of caution...don't you think?

[Lumpy]

greater tempreatures AND pressure differentials. at the leading edges the pressure differential from outside the wing to the inside is HUGE a gap will cause the heat to be sucked into the wing area. Basically the problem happened because everything that could have gone wrong and caused the failure, happened. It was bad damage, and was at a location that enhanced the problem during reentry.

Honestly it could be fixed with a loss of payload capacity, put in an emergency ablative system in place, a set of mixture tanks and nozzles that when temperatures rise to dangerous levels fire and fill both wings with rapidly expanding foam that acts as an ablative firestop AND insulation to the rest of the structure. You might lose 15% of the wing but it will be structurally safe enough to get you to the ground. I believe they even looked at such a solution as well as the newer fireproof coatings used on buildings to protect the metal during an intense blaze(another ablative fire protection put as paint) to be applied inside the entire win structure.

Problem is, reducing the payload capacity is not an option.

Re:Err on the side of caution...don't you think?

[bluephone]

agreed, that this is smaller than thought, and potentially less dangerous. I think the biggest reason they're even contemplating a repair is the fact that there's a small portion of the divot that is exposing the nomex felt under the tiles, meaning that would be the only protection for the aluminum frame. However, it's such a small portion of frame that is potentially exposed, hence all the testing. I think the felt exposure is all of three square centimeters.

Re:Err on the side of caution...don't you think?

[YGingras]

Don't get me wrong, I don't mean your regular kind of mix and spread goo, I mean the kind of high tech stuff that NASA must have invented and probably use to glue the tiles in the first place.

Re:Err on the side of caution...don't you think?

[David7]

The tiles are not incredibly delicate. They are as hard as a ceramic dinner plate but as light as a styrofoam plate.

When I was in 7th grade, some NASA PR people came to my school and did a demonstration. They took a propane blowtorch and heated a tile to the point that it glowed red. Then they walked over to a student and handed the tile to him. In the time it took to walk a few steps, the tile had cooled to room temperature.

The tile was then passed from student to student. As I said above, it was as hard as ceramic and as light as styrofoam. Even if an astronaut hit a tile deliberately with a sharp instrument, it is unlikely they could damage it.

The Achille's heel of the tile system was always the adhesive holding them to the orbiter. They seem to have dramatically improved this.

Re:Err on the side of caution...don't you think?

[MrNougat]

First and foremost - if there is a small chance of catastrophic loss of vehicle, then measures should be taken to prevent that.

Better keep the thing on the ground then, because firing the gigantic controlled explosion it goes up on certainly counts as a chance of catastrophic loss.

Re:Err on the side of caution...don't you think?

[Richard W.M. Jones]

The tile was then passed from student to student. As I said above, it was as hard as ceramic and as light as styrofoam. Even if an astronaut hit a tile deliberately with a sharp instrument, it is unlikely they could damage it.

I'm not sure what your teacher was showing you, but the Shuttle tiles are quite definitely fragile. See these articles:

If by any chance you do need to contact the tile with your hands, we would require only gentle hand reaction alone. We want you to distribute the load over several fingers or the backs of the fingers. Source

[The tile is] a rather soft piece of material. You can easily scratch it with your fingernail. It has ... a very thin layer of fiberglass on the outside. It's a fabulous insulator and NASA gave it to us to use as an insulator for an experiment we were doing. We were working at high temperatures and needed an extremely good insulator. So I had this tile sitting on my desk and it was a curiosity all along. And then it became much more meaningful when I realized that, gee, it wouldn't be very difficult at all to damage this. I could probably, with my finger, break through it. Source

The only known technology in the early 1970s with the required thermal and weight characteristics was also so fragile, due to the very low density, that one could easily crush a TPS tile by hand. Source

Rich.

Re:Err on the side of caution...don't you think?

[Megaport]

As a trained project manager,I have to take issue with this statement.

And as an engineer who is used to talking to project managers, my response to these requirements would be, "Cost, Time, Quality: Please select any two."

-M

Re:Err on the side of caution...don't you think?

[mmullings]

Does anyone know if it is possible to fly the shuttle remotely from ground control, or via computer? Just wondering if they could leave the astronauts on the ISS and return the shuttle empty...if it makes it, great, fix it up and send it back for a pickup mission. If it comes apart during re-entry, well, NO ONE DIED!

Re:Err on the side of caution...don't you think?

[Stormcrow309]

As a project manager dealing with human lives (health care), I would say Cost & Quality.

Re:Err on the side of caution...don't you think?

[toolie]

First and foremost - if there is a small chance of catastrophic loss of vehicle, then measures should be taken to prevent that.

But Secondly - and possibly more importantly; how many more shuttle flights will there be? What if there is more serious damage on the next flight? And we still have never tested the repair techniques? They already determined that this is a non-catastrophic problem.

They are now focusing the studies on determining how much repair work will be required before the next launch. That is the driving factor on deciding whether or not to repair right now. Some of the preliminary studies are showing that repairing may cause *MORE* damage to the orbiter and that is what they are figuring out now.

You can't just jump in and repair something like this without knowing all the ramifications.

Re:Err on the side of caution...don't you think?

[ah.clem]

This would be like my mom telling me she can do computer support better then me. She's a smart lady, but her KNOWLEDGE level when it comes to Computers is low.

Sounds like she'd be perfect for the job. Does she live in India?

ah.clem

Re:Err on the side of caution...don't you think?

[FailedTheTuringTest]

NASA has tried to develop a "patch kit", but has not been able to find anything that can easily be applied in vacuum and adhere well without damaging the surrounding tiles, insulates well, and is durable enough to survive re-entry. It's a tricky combination of requirements.

See the Columbia Loss FAQ web site.

Re:Err on the side of caution...don't you think?

[GrayNimic]

Read the NASA stuff, watch the NASA mission status briefings. The whole point of *doing* a repair would be to not "spoil the shuttle's schedule." This damage is not considered to be a crew-safety risk, the only risk is concern over potential damage requiring a longer turn-around time on the ground.

Re:Err on the side of caution...don't you think?

[GrayNimic]

First and foremost - if there is a small chance of catastrophic loss of vehicle, then measures should be taken to prevent that.

You say this, then go on to say that they should purposefully increase the risk of catastrophic loss for no reason other than experimentation. An EVA is considered on of the riskiest things done on-orbit (though that risk is confined to the EVA astronauts), and having an astronaut work on the heatshield creates an opportunity to further damage it. The current damage is not considered a crew risk, mearly a schedule risk (that if damage were to occur during entry, repairs could substantially increase the turn-around time before Endeavour could be flown again - and preliminary simulations indicate no such damage is likely).

They've expressed a policy of on-orbit tests being under controlled circumstances -- in the payload bay, on pre-damaged tiles -- with minimal risk to damaging the shuttle itself. Sounds like a reasonable policy to me ....

Re:Err on the side of caution...don't you think?

[StikyPad]

The problem is that "repairing" the tiles is not without risk. Adjacent areas could suffer *more* damage as the astronauts clumsily try to spread the goo in zero g. There are probably other issues as well. I'm guessing the repair substance (goo) could end up causing more friction and heating than a relatively minor hole, especially since, as it stands now, the crater is tapered gently toward the tail end, which, if there has to be a crater, is how you would want it to be shaped. If there was zero risk of fscking things up worse by attempting a repair, then sure, it would be stupid not to do it. I'm sure there are people much better trained than you and I working on the risk assessment, but getting the risk to zero will never be possible.

Re:Err on the side of caution...don't you think?

[hypnagogue]

Does someone presenting heart attack symptoms get an aspirin within the first 24 hours of being in a hospital? Do they get a beta blocker within 24 hours? 0 variations are allowed to meet their quality goal.

It's insanity like this that is the evidence that medicare is doomed. I recently went to the hospital presenting heart attack symptoms. Received aspirin, received beta-blockers. Subsequently went into cardiogenic shock followed by syncope, and followed a bit later by asystole. Yes, indeed -- they killed me.

I wasn't having a heart attack -- I was suffering from simultaneous symptoms of a gall bladder attack and sick sinus syndrome. Which, the doctors could have diagnosed if they hadn't been so quick to administer inappropriate emergency medicine, per some moron checklist.

When a project manager gets to decide mandatory medical procedures, the patients die. On schedule, and on budget.

Re:Err on the side of caution...don't you think?

[jafac]

That's my point.

Maybe we need to learn how to do this.

Maybe the conclusion is - we need to abandon the "fragile heat-tile" design, as soon as is possible. But if that is not the case, then it is obvious that this technology can not be fielded without some method of practical on-orbit repair. We're either spacefaring, or we're burning money for no reason.

Re:Err on the side of caution...don't you think?

[jafac]

How much risk was there throughout the entirety of the Gemini program?

The whole program's purpose was to learn how to perform EVA activities, and rendevous in space. Many risky launches and maneuvers, and in at least one case, a vehicle got out of control.

Yet, they did it, and learned what they needed to know in order to proceed to Apollo, and the moon.

And here we are, flying the shuttle half-assed. With only SOME of the skills and technology necessary to actually fly the thing, only on a good day, when everything goes well. The risk of the EVA and repair attempt on this ship, is probably less than the risk of the EVA and repair attempt on the next damaged ship - if the next damaged ship is *really* damaged, and we don't have the bugs worked out of our repair skills yet.

Re:Err on the side of caution...don't you think?

[jafac]

Um, in the history of space exploration, has an astronaut ever been "lost" during EVA?

Oh yeah, I forgot, 2001, A Space Odyssey. My bad.

Of course I know the risks. I'm not an idiot. I'm not saying that NASA has to go out and do it, and screw the risks. I'm saying that they need to consider that it's important to prove the repair concept at some point, before they NEED it. If it's too risky, then it's too risky - but you know, they've been thinking about this stuff since Columbia - or probably before. Someone's got to be thinking about how to remove risk from these kinds of EVAs.

Re:Err on the side of caution...don't you think?

[Stormcrow309]

I am sorry for your confusion. The CMS sets the standard, not a project manager. Expect more if Healthcare gets nationalized or if you are Medicare, since those quality scores determine where the CMS recommends where Medicare patients go. This puts a significant financial incentive to doing such for the hospital. In addition, it is safer, legally to do what the CMS recommends and have a patient die then it is to have a patient die because the hospital didn't. This is why Healthcare Law and Ethics Class sucked.

When politicians and government officials decided mandatory procedures, the patients die.

By the way, I would talk to a cardiologist about that. The beta blocker can cause cardiogenic shock and that could cause significant heart damage.

Re:Err on the side of caution...don't you think?

[coaxial]

You do realize that the attempt to repair may actually cause more damage than do nothing right? That's been the knock against the repair kit from the very beginning. Anyway, the shuttle has had damage to its titles before and nothing happened, so its not like this ammount of damage in this location is unpreceidented.

Re:Err on the side of caution...don't you think?

[initialE]

Trained professionals are getting people killed on a semi-regular basis. Perhaps we may not do better, but there's not alot of worse that you can go to than that.

Re:Err on the side of caution...don't you think?

[skeeter333]

TripMonkey, I have been watching all of the mission management briefings since launch, and find NPR's report of doubtful credibility. Several NASA centers are off working on characterizing the problem and NASA has the results of several simulations and a very neat 3D formed plastic model of the damage to work with http://news.yahoo.com/photos/ss/events/sc/010605sh uttlenasa/im:/070813/ids_photos_ts/r2562607963.jpg . The concern of course is that there is risk to the spacewalking astronaut that would perform the repair (from orbital debris, or equipment malfunction), and a risk for further damage to the TPS from just messing with it. So as always, it's a risk tradeoff: is the risk of attempting to fix it greater than the risk of not fixing it?

If all fluid dynamics simulations and arcjet testing data shows that there is likely no re-entry risk to crew safety, but a chance of a maintenance problem in readying Endeavour for the next flight, it is however somewhat ironic that a risk to the spacewalking astronaut which would repair the area in question would be acceptable to protect the schedule of missions to follow...

Re:Err on the side of caution...don't you think?

[shellbeach]

This sounded especially insane to me...if NASA loses another shuttle because of this same tile-damage problem, and because they couldn't be bothered to take the time to fix the problem when they could have, it will be the end of NASA. Oh, come on, don't you remember what the letters in NASA actually stand for?

Re:Err on the side of caution...don't you think?

[Zeussy]

Back in the Gemini days, there were not millions if not billions of flecks of paint and other debris in orbit that could kill an astronaut in EVA. We have done a good job of polluting our local space.

The damage to the heatshield is a small crator, with most of those 2 tiles still intact. If you check the anomalies log for the first Shuttle mission STS-1 Columbia lost 16 tiles and damaged 148 others and successfully landed. I think damage to a couple of minor tiles the shuttle can easily cope with.

As others have stated, the Shuttle wasn't NASA design choice, more a political pencil pushers lust. They have done very well Imho, astronauts know the there are risks, known and unknown, they accept them and risk their lives to go into space. Its their choice to fly on the shuttle and they are not forced, its a tragedy that lives are lost but if they died doing what they love and what is so horrific about that?

Re:Err on the side of caution...don't you think?

[David7]

I'm not sure what your teacher was showing you, but the Shuttle tiles are quite definitely fragile. See these articles: Please read what I wrote. The tile was provided by NASA PR people, not a teacher. I actually held it. You have only provided links to other people's testimony. Testimony that I obviously disagree with.

...but the Shuttle tiles are quite definitely fragile Before you make an assertion that contradicts a primary source, you should have better backup for your assertion than a random assortment of links to web pages. The web is not a reliable source.

"Amazing urgency"

[mwvdlee]

What does that mean?

Re:"Amazing urgency"

[operagost]

I'm amazed you don't know.

The pictures are pretty amazing and make the urgency of this whole thing much more amazing.

File it under "The Redundancy Department of Redundancy" and move on!

Re:"Amazing urgency"

[ig88]

It means CmdrTaco is semi-retarded.

Is it so urgent?

[FishWithAHammer]

Perhaps I'm missing something (and I'm sure I am), but perhaps this is something of a blessing?

Leave Endeavour in orbit. Compared to the big-mother boosters, the shuttle itself does not require a lot of fuel, and given the smaller size of the next-generation craft we're looking at, I could see a use for a "space truck" the size of Endeavour, even after the shuttle program does out the door.

Just send up something else to bring them home.

Re:Is it so urgent?

[Brane2]

There is "only" one problem with that suggestion: Shuttle can't stay indefinitely in orbit.
IIRC it is rated for week or two at the most.

Re:Is it so urgent?

[Amazetbm]

The shuttle isn't made to stay in orbit indefinitely. It has to come down at some point. I wonder if they ever retrofitted any shuttle with a system that would allow them to pilot it remotely?

Re:Is it so urgent?

[icebrain]

As of now, the shuttle is capable of a fully automatic landing--except for the part about lowering the landing gear. NASA came up with a rube goldberg-looking method to do that, involving running a couple cables to various places, loading a special flight software version, and sending a certain command at a given time (or something like that). I've read the entire procedure before on usenet; can't access it here at work though.

Re:Is it so urgent?

[Boilermaker84]

It is a resource issue. This mission is 14 days with some additional days in reserve for bad weather issues with landing. That limitation is mostly a crew environment issue (need to generate water and oxygen, have food on hand, etc.)

The vehicle could stay up longer in an unmanned configuration, but still has limited fuel resources to run the OMS. The shuttle just isn't designed to go anywhere but orbit and back.

Re:Is it so urgent?

[Himring]

I could see a use for a "space truck"

The Space Shuttles are more like "space tubes."

Re:Is it so urgent?

[everphilski]

More like a month or two, disconnected from ISS, though it would not be fun. If shit hit the fan, the backup plan is to fast-track the next orbiter for a rescue mission. Or at least that is my understanding.

Re:Is it so urgent?

[Amazetbm]

Okay. Because I know the Russians had a system like that on their shuttle....then they ran out of cash.

Re:Is it so urgent?

[YrWrstNtmr]

The reason for the landing gear part is because that is a 1 shot deal. The Shuttle must be going less than 300kts when the gear is deployed. And there is no 'retract'. Once the gear is deployed, that's it. It can only be raised in ground operations. And you cannot reenter with the gear down. And after reentry, above 300kts you might tear the gear off. If the computer burps at the wrong time, scratch one shuttle.
For just about every other problem, there is a workaround. Fire the reentry rockets at the wrong time? Not great, but you can land at a different runway.

Other than that, it could be completely guided from the ground.

The Russians flew theirs unmanned, and it only flew the once, because the crew module and software wasn't finished.

Re:Is it so urgent?

[FatAlb3rt]

The reason for the landing gear part is because that is a 1 shot deal. Entry is a one-shot deal too. Post-deorbit burn, you're coming in whether you like it or not. There's some politics involved too. Flight software defines events as Major Modes - it'd be very simple to not allow the DeployLandingGear command to be issued outside the Approach and Land phase (MM305?). The politics come in by way of the astronaut office - by requiring a person to push the button, the astronauts are now assured of a job.

Re:Is it so urgent?

[Chris Burke]

I could see a use for a "space truck" the size of Endeavour, even after the shuttle program does out the door.

Oh sure, but you know how it is. As soon as your buddies find out you have a space truck they'll want you to help move their space sofas into their new space condo.

Re:Is it so urgent?

[petermgreen]

I could see a use for a "space truck" the size of Endeavour, even after the shuttle program does out the door.
the problem is despite the sci-fi scenes of space stations keeping stuff in space permanently is really only usefull for doing experiments inside it. By the time a craft get's to orbit it is almost out of fuel and so it is basically stuck in that orbit until it uses the atnosphere to burn off it's velocity and come into land.

Re:Is it so urgent?

[DerekLyons]

The vehicle could stay up longer in an unmanned configuration, but still has limited fuel resources to run the OMS. The shuttle just isn't designed to go anywhere but orbit and back.

The critical path item that controls longetivity on orbit is the cryogenics for the fuel cells - when that runs out, everything on the shuttle dies. (The shuttle has no batteries to speak of. [1]) Even with the fuel cells supplemented by power drawn from the station [2] and everything possible powered down, the cryogenics will run out somewhere around (IIRC) the 30 day mark. (Depending on how deeply and how early you power down the shuttle.)
 
The normal endurance for a solo shuttle is around 14 days maximum. They key parameters to endurance in a 'lifeboat' scenario are a) you've already 'burned' 4 days worth of cryogenics (roughly) just getting to the station, b) how soon and how deeply you power down the Shuttle [3] and c) keeping Shuttle life support operational as long as possible to avoid drawing on the station's supplies (while maintaining enough reserve to deorbit the damaged shuttle).
 
[1] Even with today's batteries, let alone those of the era the shuttle was designed, it simply is not possible for the shuttle to carry a big enough battery pack to be useful.
 
[2] The station cannot fully power the shuttle - neither the shuttle or station power distribution system is sized for it. (When the shuttle is drawing full external power, it comes in via umbilicals near the tail and distributed via buses located in the walls of the cargo bays.)
 
[3] There are limits to what you can and cannot turn off depending on your ultimate goal. And some things (like the heaters to the RCS system) simply cannot be turned off at all without irreversibly damaging the components. (The shuttle, like most spacecraft, is biased 'cold' (if it were completely passive) because it is much, much, easier and lighter to heat something than to cool it.)

Re:Is it so urgent?

[dbIII]

Leave Endeavour in orbit.

While it was never intended to stay that may actually be possible. It would have a bit of fuel onboard for re-entry (the atmosphere does most most of the work but there must be some fuel for burns to reduce the velocity) so there may be enough to keep it up in LEO for long enough to work out how to turn it into an ISS module and keep the entire thing up or for progress rockets to bring up more fuel. As for bringing them home - the Russians have that organised and I believe it is the same as their Mir evacuation plan from a long time ago.

Re:Is it so urgent?

[alienmole]

The politics come in by way of the astronaut office - by requiring a person to push the button, the astronauts are now assured of a job.

Now I have this image of a group of suited-up astronauts floating outside the ISS, picketing it...

Re:Roland

[Mannerism]

Nay, 'tis not to be. Like Lance before him, he too shall continue to plague the Earth's surface.

Exclusive images?

[jdhutchins]

I wouldn't call those too exclusive.... look at the "3D Video of Endeavour Tile Damage" video on this page: http://www.nasa.gov/mission_pages/shuttle/main/ind ex.html

Re:Exclusive images?

[MobyDisk]

When did NASA start using RealVideo? I thought they used to use standard formats. Yay, my tax dollars at work undermining standards to prop-up proprietary formats.

Exclusive? Yeah right...

[ExE122]

I bet those are pictures of Roland's bathroom floor.

--
Capitalism: When it uses the carrot, it's called democracy. When it uses the stick, its called facism.

My question

[j-min]

When is NASA not going to have damaged tiles during a shuttle launch? I haven't been following the story until now but it just seems silly to send some of our best minds into space in these antiquated shuttles.

Is there expected to be as much danger for this shuttle mission as there was for Columbia?

How big is each tile?

[Ayanami Rei]

It's only two tiles that are damaged, but how big are they in the first place?
They're not done running simulations for the effect on re-entry, but that non-smooth edge between the two damaged tiles in the gouge would worry me no matter the outcome with that much more friction and eddying.

Re:How big is each tile?

[ArcadeX]

Saw a demonstration once where they took a blowtorch to one of the tiles, it was little more than a few inches on a side.

Re:How big is each tile?

[bitfarmer]

I doubt it matters how big the tiles are. The thermodynamic stress of reentry is unbelievably huge -- once plasma gets beneath the exterior there's almost nothing to stop it from going wherever it wants to go, including shearing adjacent tiles, the 'zipper' effect. All you need is a small hole probably like this one to get a chain reaction started.

Damage like this has probably been happening of most, if not all, launches since the beginning of the program. You can bet if Richard Feynman were alive today, he'd be standing on top of a table right now somewhere screaming about NASA playing 'Russian Roulette' or some such thing.

Re:How big is each tile?

[jridley]

If they're typical tiles and they haven't drastically changed things from the demo they have down in Florida that I looked at 10 years ago, they're 3 or 4 inches on a side. The NPR story this morning said the gouge was 3" long.

It looks borderline to me. I think they've successfully landed with much bigger gouges or missing tiles in the past, but it probably depends on WHERE the gouge is. If it's in a flat part of the belly, it's probably not a problem. If it's near a leading edge, more of a problem.

Re:How big is each tile?

[wytcld]

it probably depends on WHERE the gouge is

Where, and what the turbulence pattern will be there, and how much heat will be directed right to that small spot of bare metal skin. Then there's the question of whether they have good enough computer models to predict that to any accuracy; or whether minute changes in angle-of-approach and so forth render the chances essentially random. Since they have a patch kit, they'll be fools not to use it - unless the patch could itself deform into a funnel channeling the fire of re-entry to that spot.

Re:How big is each tile?

[ZOMFF]

6 inch by 6 inch but can very in size depending on location on the shuttle.

Re:How big is each tile?

[ACDChook]

Now obviously I have no qualifications in this area, and I can't say to be totally knowledgeable of hypersonic aerodynamic heating principles. But it occurs to me that some eddying could, depending on the exact airflow in the damaged area, help to lower temperature in the gouge. After all, if there was some eddying, it would mean airflow breaking down and circulating much more slowly within the damaged spot, so the friction would be less in that particular area.

Re:How big is each tile?

[jridley]

From what I understand, all the patch procedures stand a significant chance of causing direct damage to surrounding tiles. Also they may leave a bump and that may cause the tile to be completely ripped out. Also there's a danger involved with any EVA.

I don't think they'd be "fools" not to use it in any case at all; it depends on what the chances are.

You're not a fool to get out of bed and drive to work in the morning even though it increases your chance of getting killed. But you'd be a fool to decide one day to swim across the atlantic without training, because that VASTLY increases your chances of getting killed.

Direct link to the images.

[roman_mir]

Image 1
Thermal Image
Image 2
Image 3
Image extracted from a video made by Neptec LCS

Re:Direct link to the images.

[pragma_x]

The thermal images you linked have to be the scariest of the the set. The center of the gash is clearly not insulated as it's a dramatically different temperature than the exposed tile material around it. IMO, it illustrates how bad the situation is better than the optical images we've all become familiar with thus far.

I'm convinced. Attempting to land this orbiter without repair would be like attempting the same with the windows open.

Re:Direct link to the images.

[TheMadcapZ]

That "thermal" image is in a scale of inches. The depth of the gash is a little over an inch.
You really should know what your looking at before you become convinced of something.

Re:Direct link to the images.

[Dashing Leech]

That's absolutely correct. It's not thermal. If you look at the article or go to the source images on Neptec's site (and caption info), you'll notice it says it's a false-color depth image, meaning the color indicates it's depth below the surface according to the scale on the side. The damage is about 1.2 inches deep and a little bigger than your thumb in diameter.

This isn't really an issue of insulation. It's the disturbance of laminar flow. The laminar boundary layer is actually quite a good insulator itself, especially at Mach 20. The main issue is how much the hole disturbs the boundary layer and what localized heating might result. This small of a hole in diameter, even though it's mostly through the tile, should be mostly negligible. But NASA is treating it VERY seriously and is doing simulations as well as has an arc-jet facility to test on an exact duplicate of the damage. (It's a 3D model of the hole, if you check the video, and is easily reproduced on the ground. It has even been printed out with a 3D printer.)

Remember that Columbia damage was on the Reinforced Carbon-Carbon (RCC) panels on the leading edge of the wing, not the tiles on the belly. The leading edge is one of the hottest and most critical points where that damage occurred. This damage is generally low risk, and EVA is always risky to some degree, but this might be a great opportunity to test repair procedures. When people talk about whether NASA is making decisions based on schedule for this damage, it's not about ignoring risks for the sake of schedule. Risk wins, easily. The schedule issue is that if the damage is not a risk at all, is it prudent to fix it anyway to test procedures and have an actual flow repair to analyze upon return. Remember, EVA and extending flights adds risk to the crew too, but can be beneficial and reduce risk both for this flight and future flights.

Re:Direct link to the images.

[pragma_x]

Quoth the GP: "Thermal Image [blogsforcompanies.com]"

Depth-map or not, I still stand by my sentiment; an inch can be a lot at re-entry speeds. Other slashdotters have noted that this is in a "colder" area of the heat shield during re-entry, so there's not much to worry about were it left alone. I'm doubtful that's a risk worth taking.

Re:Roland

[BladeMelbourne]

The Slashdot spam, Hawaiian shirt and queer glasses means Roland will never be in space. I like the idea of a Roland sacrifice though ;-)

The solution.

[Anonymous Coward]

They should get Xzibit and Chamillionaire into space ASAP so that beat-up ride can be pimped.

Re:The solution.

[east coast]

We'z gonna fix yo bucket! What we haz right here is a crack in da tile instead of crack in da vile.

Word! Pass dat pipe, homie.

Re:The solution.

[mikelieman]

They should get a quart of refractory cement and a trowel ( or a plastic glove, to just smear it on... )

Re:The solution.

[Anonymous Coward]

...Fuck you. Seriously.

must be expensive images

[Anonymous Coward]

judging by the amount of space on that site dedicated to advertising
sad.

Re:must be expensive images

[Zibblsnrt]

I'd figure anything that attracted Slashdot's attention would quickly become somewhat more expensive to host, yes.

Yikes.

[noSignal]

It seems like every launch in recent memory has resulted in some sort of damage to the shuttle. I wonder if this is a new development (maybe ageing fleet?) or if it used to happen on every launch but nasa pays a whole lot more attention to "minor" damage now after Columbia. NASA seems to think that this is not a big deal. From nasa.gov:

Mission Management Team Update
Mission managers have determined that damage to a small section of Endeavour's heat shield poses no threat to crew safety or mission operations. However, they are discussing options for possible repair work that would ensure preparations on the ground for Endeavour's next flight will go more smoothly. The damage occurred during the climb to orbit on Aug. 8. I hope so.

It can actually stay at the ISS a lot longer now.

[Anonymous Coward]

The last shuttle mission (and this one) installed equipment that allows the Shuttle to draw electrical power from the ISS's solar arrays and electrical grid, rather than being limited to the Fuel Cell consumables on the Shuttle itself (which is where the aprox 2 week number on orbit endurance comes from).

A good public debate

[cryfreedomlove]

I like the fact that our society is open enough that this information and this debate is public. There are many governments in this world today who would not allow this information to be released and would make the decision based on cloaked objectives and goals. The USA has its problems (e.g. the stupidity of Iraq) but it sets us apart that this is happening in the open. Nobody is going to get arrested for debating or questioning this intense and sensitive topic.

Re:A good public debate

[Anonymous Coward]

Thank you for your comment. It has been analyzed and approved by the NSA and the CIA. A copy of your comment (and your voting record) will be kept on backup indefinately at our Langley VA storage facility.

Re:A good public debate

[Anonymous Coward]

Thank you for informing us that the USA is the best country in the world. You may now continue singing the national anthem. God bless.

Re:A good public debate

[Potor]

all your comment implies is really how unimportant this damage probably is.

bad tiles?

[thatskinnyguy]

This had to have been happening the past 30 years if they have gone with the same materials and it didn't become a problem until 2003 when Columbia disintegrated on re-entry. What changed between 1977 and 2003? Did they change manufacturers of the tiles? Or is this series of gaping holes after each liftoff a fluke?

I've never heard of the Russians having problems like this. Of course their Soyuz workhorse is a totally different and more efficient design.

Re:bad tiles?

[icebrain]

More efficient by what standards? Price? For just bringing up a couple of crewmembers, Soyuz probably is. But if your mission involves delivering lots of cargo, it might not be.

Re:bad tiles?

[Volante3192]

Never heard of tiles coming off the Mercury, Gemini or Apollo capsules either.

There's something to be said for that whole 'protecting the heat shield on launch' design. Don't get me wrong, I love the shuttle, and I'm sure they meant very well when it was designed (hell, I'd've gone for it) but now that they've been stuck with it the flaws really start to stand out. Clipper ship in space is right; beautiful lines...but who uses clipper ships anymore?

Re:bad tiles?

[iminplaya]

I think the Russians are making more cargo deliveries also. Without a pilot, besides. At this point, I would also consider their way of doing it more efficient, and reliable. Their space truck is a Chevy. Ours is a Ford. For people, they use a compact. If it wasn't for them, we probably would have had to abandon the space station a long time ago.

Re:bad tiles?

[Robonaut]

Mercury*, Gemini, Apollo, and Soyuz all use(d) ablative heatshields that burn off as they reenter. The ceramic tiles (and carbon-carbon) are the most common material used in reusable heat shields like those on the shuttle (also a number of next gen spacecraft (X-Series and the Kistler K-1). There were numerous concerns with the heatsheilds on previous spacecraft including concerns over John Glenn's Mercury flight (they kept the orbital maneuvering unit connected to the craft to hold the heatshield on) and Apollo 13, where there were concerns that the cold temperatures (the heaters were turned off after the explosion) may have cracked the heat shield. *The first two Mercury flights were suborbital and did not require the same type of heatshield because of lower temperatures.

Re:bad tiles?

[Anonymous Coward]

Never heard of tiles coming off the Mercury, Gemini or Apollo capsules either.

Maybe that would be because those didn't use tiles? Mercury, Gemini and Apollo used ablative heat shields. The space shuttle uses an almost pure thermal soak heat sheild. They are two totally different mechanisms, and comparing the two is just stupid.

Re:bad tiles?

[YrWrstNtmr]

Soyuz = VW Beetle (880kg)
Progress = pickup truck (2,500kg)
Shuttle = tractor trailer (25,000+ kg)

Different vehicles for different uses.

Re:bad tiles?

[WhatAmIDoingHere]

But the problem is that our tractor trailer is designed to do neither cargo nor crew well. If we had a vehicle to transport crew safely and a remotely piloted vehicle to transport only cargo it would be safer for the people and cheaper for the cargo.

Re:bad tiles?

[iminplaya]

The VW and pickup truck have proven to be very reliable, part of what makes them efficient. If our tractor trailers ran as badly as the shuttle, the country would be brought to its knees in a week. It doesn't matter how much weight you can carry if you can't make the deliveries. The shuttle was supposed to be able to launch 12-15 times a year. What are we getting? Twice? If we're lucky? Too bad we didn't keep the Saturn V operational.

Re:bad tiles?

[FailedTheTuringTest]

Yes, it has been happening for the past 30 years. That's partly why Columbia came down in pieces: NASA had gotten accustomed to repairing a little bit of minor damage after each flight, so it was considered routine. Unfortunately Columbia's damage was worse than earlier flights, and in a location where it couldn't be seen.

That was the problem

[ipjohnson]

the rocket scientist weren't allowed to do there jobs before smart ass.

Re:That was the problem

[Anonymous Coward]

The rocket scientists weren't allowed to do where jobs before smart ass?

Re:That was the problem

[shadowbearer]

  Pretty much. ;(

SB

Without a scale...

[argStyopa]

Without a scale to compare to, the gouge looks HUGE and devastating.

I've heard on the radio that they are discussing a roughly 3" scrape....which, if scaled to the longest axis, is objectively pretty small, but when considered against the turbulence, heat, and pressure that those belly tiles are faced with? It looks huge and devastating again.

Those astronauts have balls of steel if they ride that thing down again.

Re:Without a scale...

[Volante3192]

Astronauts have balls of steel to begin with. Two sets. You're sitting, surrounded by just how much in explosive fuel? Blasted into one of the most uninhabitable climates for human survival. (Ranks up there with volcano caldera and bottom of ocean...) Then set on a 100 mile free fall course to the Earth, the same trip many meteors take, and burn up well before hitting the ground most of the time.

And yet I so want to do it for myself...

Re:Without a scale...

[iminplaya]

Those astronauts have balls of steel if they ride that thing down again.

Considering the make up the present crew, I believe "nerves of steel" would be a bit more appropriate.

Re:Without a scale...

[cyphercell]

Astronauts have balls of steel to begin with. Two sets. You're sitting, surrounded by just how much in explosive fuel?

Smart and Brave, hell the thought of sitting on two sets of steel balls both confuses me and puts fear in my heart.

Of course I'm sure when they're old their sacks hand down to their ankles.

Re:Without a scale...

[192939495969798999]

Don't forget the stomach of steel too... can you imagine what it feels like to be permanently suspended in the "barfy" state that most upside-down roller coasters do for just an instant?

Re:Without a scale...

[rhainman]

They'd have bigger balls of steel if they just stayed in orbit forever.

Re:Without a scale...

[dstone]

Without a scale to compare to, the gouge looks HUGE and devastating. But there is a scale on the right of the thermal images. It suggests the depth of the deepest part of the gouge is more than an inch. Then with the oblique angled shots, you can start to estimate the overall size. So it is probably several inches across, like they're saying in other media. They might be deriving an eyeball estimate like I am, though.

So, HUGE damage? No.
Devastating? Could be, leave that to the rocket scientists.
Astronauts with balls of steel? Yes.

Re:Without a scale...

[freeze128]

Those astronauts have balls of steel if they ride that thing down again.

Well, What's the alternative? Either ride the shuttle back home, or ride the ISS back home.

One of them actually HAS landing gear...

Re:Without a scale...

[rhadamanthus]

Oh for the love of....

Each tile is 6x6 inches. The damage is about 3 inches long. Length however, does not matter - it's all about depth. In this case, the tile is 1.14 inches thick, and it is believed that the damage is through the entire width, exposing the filler bar/RTV adhesive under the tile edge. This implies no ceramic insulation for the aluminum skin. Before more slashdot armchair NASA engineers make ridiculous claims, understand that fluid flow into a cavity of this geometry will choke, lowering the heat rate. Also, this damage is conveniently under an aluminum structural assembly, giving the vehicle significantly more dissipative capacity. I think you'll see this thing cleared for reentry.

Re:Without a scale...

[Lumpy]

Astronauts have balls of steel to begin with. Two sets.

you are incorrect. Those specifications have been revised since Mercury and are no longer used

Astronauts, male or female are outfitted with titanium coated aluminum balls. These are far lighter and cause less problems on launch and reentry. NASA is currently testing new carbon fiber composite balls but initial tests from volunteers have reported problems of ichyness and unnatural feel.

The titanium coated aluminum balls have been standard issue since Apollo 14.

Re:Without a scale...

[Anonymous Coward]

Not to mention, the shuttle is a blunt body re-entry design to begin with. Air trapped against the belly is relatively static compared to it's 17000 mph velocity.

Somebody above claimed with the drag against this hole's edges would "zipper" all the other tiles off, but between the low amount of circulation close to the hull during re-entry heating and the fact that the worst wind shear occurs after the worst heating when the shuttle has reached the thicker parts of the atmosphere and pitched the nose down to glide, I'm sure there's pretty much zero threat of that. NASA has no doubt performed sheer and pull tests on the adhesive of these tiles and taken that data into account analyzing this.

Personally, I think they will repair it anyways. They've mentioned the heating may be enough to warrant more costly and lengthy repairs to the skin and possibly frame after landing. They have the new power hookup from the station, so they don't need to run the fuel cells down to stay at the station longer. Working underneath the shuttle is considered risky, but they did it before when they EVA tested their repair epoxy and the boom on STS-114. They'd probably also don't mind testing the epoxy on real damage and a real re-entry, since they have the chance.

Re:Without a scale...

[StikyPad]

I'd do it too. Aside from a launchpad fire a la Apollo I, any other type of failure would almost definitely be a quick and painless death. We risk a slow and agonizing death every day no matter what we do, typically for a much smaller reward. The experience and memories of a successful trip to LEO would be a well worth the risk (to me, at least). And if you have to go, you might as well go out in style. In that light, I don't think it takes a particularly large set to go into orbit; I think it would take profound cowardice to stay on earth, given the choice. I guess there's arguments to be made about caring for loved ones, but a nice insurance policy would help, and I'd rather be remembered as someone who tried and failed than never have tried.

Re:NRA

[cbreaker]

We finally really did it.

wrong

[everphilski]

Oh, and for another tidbit. Ice, since its denser, and heavier than the insulating foam, is a bigger problem than the foam is when it breaks off. It takes a smaller chunk of ice to break off and smack the orbiter to cause an equivalent amount of damager to a larger chunk of foam.

Foam does more damage than ice. Ice is dense and keeps its velocity high, which translates to a low velocity relative to the shuttle. Foam on the other hand is much less dense and slows down very quickly, translating to high velocities relative to the shuttle.

Remember, kinetic energy = 0.5 * mass * V^2. Velocity is what kills, not mass.

Re:wrong

[igjeff]

Ok, I'll buy that as being possible.

Only parroting comments I heard from folks while watching NASA TV (I've been playing with multicast on our network and NASA TV is a nice good stream to multicast around). Perhaps I should've clarified that statement as also being comments that I had heard from relatively authoritative sources...I don't mean to make any claims of absolutely truth on it.

There were also some references (if I remember correctly) to the velocity of whatever substance impacting the orbiter was a result of the delta-v of the shuttle, rather than the delta-v of the chunks of whatever. Some indications that this is the reason that foam impacts in the first minute or so after launch were the most problematic because that's when the delta-v of the shuttle is highest, apparently.

I'm no expert, here, just passing on comments I've heard watching this stream...whether its all legit or not, I'll let you decide.

Re:wrong

[everphilski]

That's not to say that ice does not cause damage; just that the physics of the flow field cause the foam to be more damaging contrary to intuition. It is pretty much consensus that a suitcase-sized piece of foam did Columbia in, and most sources I've heard this week are citing foam although I have heard ice thrown around.

Re:wrong

[Anonymous Coward]

it is contrary to intuition, and it is wrong.
ice has larger momentum, since its mass is higher. the difference in speed is not enough to compensate for that.

Re:wrong

[Thuktun]

Foam does more damage than ice. Ice is dense and keeps its velocity high, which translates to a low velocity relative to the shuttle. Foam on the other hand is much less dense and slows down very quickly, translating to high velocities relative to the shuttle. This argument makes no sense to me.

Ignoring air resistance, which won't be much different for similarly-shaped pieces, once detached from the shuttle, pieces of ice and foam would accelerate towards the ground at the same rate. The shuttle continues to accelerate upwards at the same rate relative to the two. Ice has higher density and would thereby accumulate consequently higher momentum and greater kinetic energy than the foam. Since ice is also much harder and would deform less, it would clearly be the more significant impactor.

Re:wrong

[jswigart]

Sure, if you ignore the most significant part of the equation(air resistance).

Re:wrong

[everphilski]

Ignoring air resistance, which won't be much different for similarly-shaped pieces, once detached from the shuttle, pieces of ice and foam would accelerate towards the ground at the same rate.

You can't ignore air resistance at low altitudes (the impact happened in the first 2 minutes) at supersonic speeds! Acceleration due to gravity is negligible due to the timeframe, we are talking fractions of a second. So for similarly shaped pieces, the drag force will be similar. The lighter piece, foam being much lighter than ice, will slow down very quickly. Now we approach the shuttle which has not slowed down. We have a large speed differential between the foam and the shuttle, whereas between the ice and the shuttle, there is very little speed difference.

Re:wrong

[FailedTheTuringTest]

The Columbia Accident Investigation Board report is unambiguous on this: "a breach in the Thermal Protection System on the leading edge of the left wing, caused by a piece of insulating foam which separated from the left bipod ramp section of the External Tank at 81.7 seconds after launch, and struck the wing in the vicinity of the lower half of Reinforced Carbon-Carbon panel number 8." In Elsewhere, I've seen the size of the foam estimated as 50 cm x 40 cm x 15 cm. The report also says that NASA's decision-making and management processes were broken. (The CAIB report is quite readable and interesting, and has lots of photos -- have a look if you're at all interested in the shuttle.)

Re:wrong

[burtosis]

What I don't see right away is how the energy balance works here. Lets say both pieces are the same shape (and keep the same orientation through the fall) so the drag FORCE is the same. Now lets say the distance to the target (perhaps the wing edge) is also the same.

Energy not only equals .5 x m x v^2 it also equals FORCE x distance.

Therefore if you have the same distance and the same force, you wind up with exactly the same kinetic energy at impact thought the speeds and impact times differ.

My $0.002 (given that I have not actually checed this issue out thouroughly) is that it may be more of a matter of when and where the foam breaks off from vs. the likely places for ice to form.

Re:wrong

[yknott]

You are correct in saying the force would be the same. However, due to the difference in densities, equal forces result in different accelerations. Force= mass * acceleration , thus acceleration = Force/mass. If you have 1/2 the mass, you will have twice the acceleration. This acceleration is negative, i.e against gravity. This goes back to what everphilski was saying. The foam slows down more, i.e the delta velocity between the shuttle and the foam > delta velocity between the shuttle and the ice. This is where the kinetic energy comes into play.

Re:wrong

[burtosis]

Actually the parent incorrectly thought the KE (kenetic energy to those skilled in the art) would be different for two densities when in fact they are the same.

If you were to go on to read my post you would notice this:

Therefore if you have the same distance and the same force, you wind up with exactly the same kinetic energy at impact thought the speeds and impact times differ.

Thus the impact velocity is different only because KE is identical in all cases and the different mass forces different accelerations and thus constrains the impact velocity.

The units of energy are Ft-lbs for the reason work is defined as force x distance.

THIS IS INSANITY!

[Anonymous Coward]

Anyone can see that this damage is all the way to the bottom of the tile! The tile is effectively gone! There is NO WAY that is going to withstand re-entry! Anyone with half of a brain can plainly see that this is FATAL DAMAGE! The same go-fever that has killed crews on Apollo, Columbia, AND Challenger is now going to kill Endeavor. This is infuriating! It's stupid! It's misguided! It's plainly insane!

This will be the last flight. It's over, NASA is insane and no longer qualified to fly to space. If this is not the final nail in the coffin of the shuttle program, then our government as a whole has failed us. We need to immediately ground the shuttle, defund NASA entirely, scrap the whole thing, and give control to private industry. Leave the launching to the Europeans, they're the only ones who seem to be able to get it right.

If Richard Feynman were alive today...

[Ayanami Rei]

... he'd be standing on top of a table right now screaming about something, NASA shuttle in space or not. He was a pretty intense kind of guy who could get away with standing on tables, soap boxes, and other tall things.

Re:If Richard Feynman were alive today...

[bitfarmer]

... he'd be standing on top of a table right now screaming about something, NASA shuttle in space or not. He was a pretty intense kind of guy who could get away with standing on tables, soap boxes, and other tall things.

True. He was a passionate guy who cared about things like that. He also had startling insight and an annoying habit of being right most of the time.

Cloaked objectives and goals

[Anonymous Coward]

Speaking of which, why don't you come out in the open and state specifically which Asian communist space-race competitor you are making a jab at?

Re:Cloaked objectives and goals

[_Sprocket_]

Speaking of which, why don't you come out in the open and state specifically which Asian communist space-race competitor you are making a jab at? Its not commentary on an Asian communist space-race competitor. It's a commentary on an extraterrestrial space program. It's just that the Scientologists get really aggressive when you criticize their church.

More information

[AkumaReloaded]

More information on the size and use of the anti-heat tiles or High-temperature reusable surface insulation (HRSI) can be found in this article on wikipedia: http://en.wikipedia.org/wiki/Space_shuttle_thermal _protection_system

It seems they are not that big, and I do not think one or 2 damaged tiles whould have a massive effect on the safety of the shuttle. However if someone leaked that tiles were damaged (no matter how few tiles) and NASA did not act on it, the public would be outraged. So perhaps NASA thinks its best to mention this in public and fix it, even if it doesnt have to be fixed at all. Or what if the chance is 1 in a million that it has any effect, NASA doesnt act and the thing crashed, people would be outraged as well. Better safe than sorry.

Neptec's own website, too

[SuperBanana]

look at the "3D Video of Endeavour Tile Damage" video on this page [of nasa's website]

Or on Neptec's own website.

Why can't slashdot accept stories that directly link to the content, instead of forcing us to go through Roland's inane commentary?

Re:Neptec's own website, too

[Fifty Points]

Bold tag is bold

*Yawn*

[Anonymous Coward]

Those are some dinky little low resolution pics. Here's one of Endeavor with the Earth as backdrop, today's NASA "Image of the day". Yesterday's is spacewalking astronaut Rick Mastracchio fixing something outside the space station. Here it is taking off, and here's another liftoff pic. These are all of the present mission that's still up there inspecting tiles. Here is the "Image of the day" gallery. These are bigassed, high resolution pictures, most of them breathtaking.

-mcgrew

Re:[AC]THIS IS INSANITY!

[everphilski]

Leave the launching to the Europeans, they're the only ones who seem to be able to get it right.

Whens the last time the Europeans have launched humans into space? *crickets* ...

Delicate tiles

[electromaggot]

What's interesting is how delicate the tiles are. I saw a presentation by a NASA guy some time ago and I was allowed to hold the tiles. They're extremely light, almost feeling like their core is some kind of foam. The black ceramic layer on top is surprisingly thin.

I asked the presenter specifically about how delicate they felt. He then "flicked"/snapped the tile with his finger/fingernail, which put a sizeable dent into the tile, easily cracking the brittle black layer, and you could see the white foam underneath.

Therefore, it's no surprise to me to see this kind of damage. It probably wasn't even impacted with what could be considered excessive force.

Makes you wonder what kind of tile damage shuttles had -- all those successfully landed shuttle missions -- before such close scrutiny.

Re:Delicate tiles

[AaronLawrence]

Is there anything better these days? Could they substitute something else? I'm guessing not, because otherwise they probably would have done it. Interesting to think that state of the art material from 30 years ago is still state of the art.

Re:Delicate tiles

[Anonymous Coward]

My friend's father worked at Lockheed in the late 80's, and gave us a tour of their fabrication and testing facility. I got to see the ovens where those tiles are baked (and the sister Enterprise ship for simulations). I asked about the material, because on the shuttle it looks like armor but indivdually it looks like you described; flimsy foam with a piece of glass on one side. Yup, they're mighty delecate things, those tiles, because that's what they are - foam to glue them into place and glass to shield against heat. Well, technically it's more like a ceramic glaze than a piece of glass. Not much of a difference, IMO.

He went on to explain that the surface of the shuttle, even the bottom, doesn't need much protection from impact because it's near impossible to protect the shuttle from, say, micro asteriods traveling so fast they punch a hole in any material known to mankind. It's space travel, it's not safe.

In re-entry you don't really have to worry about hitting any particles or birds or anything. The wake that's made pushes everything away from the shuttle, and anything that's stupid enough not to get out of the way is vaporized in that plasma wake. So the tiles don't have to protect against impact, just heat. That flimsy material is flimsy because it's the only stuff that can handle the heat without being a) too heavy, and b) warping so far out of shape the whole shuttle becomes deformed. It may look and feel flimsy, but what other material do you know of that can withstand so much friction and super-heated air and not peel away or disintegrate?

I've seen a couple of comments about using metal, like titainium. Neat. Each tile would have to be super small. And replaceable. Even the special can-withstand-thousands-of-degree ceramic tiles are tiles because there is some warping. If the bottom of the shuttle was solid it'd lose it's ability to fly right away. If the tiles are too small, it not only costs a whole lot more to service and maintain it runs a higher risk of losing pieces in a cascade failure.

Flight check! Meaning: wiggle 100,000 little pieces of shield to make sure their tight and don't tear off and break the ones around it. Um, yeah.

The fact that tiles break off or get impact damage is part of the design that is a tiled, ceramic surface. It's routine, and my friend's dad said that the typical re-entry loss of tiles was (IIRC) around 10%, especially around the nose. The real problem is, as some have pointed out, the leading edge of the wings. Gotta have wings for when you want to stop falling down and keep falling sideways, and wings gotta have a leading edge and not be too flexible nor too ridged, and that leading edge has to be as if not more hardcore than the nose in terms of withstanding abuse. Kinda stuck in the paradigme of making a vehicle that is both space ship and air ship.

Yeah, there's better ways to do it now. That was, what, almost 20 years ago that I saw a design made almost 30 years ago. But, in truth, it's really a good design to have held up better than any fleet of cars and planes. I think only trains and boats have a better track record, plus the shuttle has a much rougher road to get thru.

The disaster wasn't so much that a tile got broken. Tiles get broken all the time. The problem is *which* tile got broken, because that one broke in such a way and in such a place that plasma entered the wing, weakening the support for the wing, which caused the shuttle to experience *major* turbulance (as opposed to the minor, or expected turbulance of re-entry), and the resulting loss of yaw and pitch ripped the whole thing apart.

nothing changed

[everphilski]

Probability of a critical hit doomed Columbia, and it has been protocol to check for damage before re-entry ever since. The media then keeps tabs on Nasa TV and the press conferences and blows it into a huge deal, regardless of severity.

Its like Jim Lovell's wife said in Apollo 13 (rough, sorry, its been awhile): "No one was interested in his transmission, but now that they are up there and in trouble the world is interested?" ... "Get off my lawn! If they have a problem with it they can take it up with Jim when he gets back!"

Roland Piquepaille?

[LordSnooty]

Blimey, he's done well for himself. All those /. links to his blog did some good.

Portrait

[njfuzzy]

Okay, this is a silly thing to point out, but it is driving me crazy. Why on earth does Roland P.'s portrait on ZDNet have obviously drawn-in yellow glasses???

Re:Portrait

[Radon360]

When I saw those ugly yellow frames along with the yellow shirt and plastered comb-over, the first thought that crossed my mind was he's gunning for a role in one of those Vytorin commercials (you know, where they compare a person with a goofy wardrobe with some entree). The question is, what dish would they match him up with? A banana split?

Re:Portrait

[Anonymous Coward]

That's not him. That's a stock photo of an anonymous person with the glasses drawn on afterwards.

He does this to preserve his anonymity so he can walk down the street without being mobbed by adoring fans.

Re:Portrait

[vertigoCiel]

They're not drawn in, they're just extremely bright. Take a look on the left side of the picture, where the earpiece recedes - you can see they're actually on his head. I don't think anyone would take the time in to photoshop those ridiculous things on him.

Repair Kit?

[Darth Muffin]

As part of reinstating the Shuttle fleet, didn't NASA put a repair kit onboard for just this type of thing? If they say it's not a big deal I'd have to believe them, it's probably a very common occurrence. However, how hard can it be to go EVA and trowel in some space-spackle just to cover their butts?

Re:Repair Kit?

[WombatControl]

As part of reinstating the Shuttle fleet, didn't NASA put a repair kit onboard for just this type of thing? If they say it's not a big deal I'd have to believe them, it's probably a very common occurrence. However, how hard can it be to go EVA and trowel in some space-spackle just to cover their butts?

It involves an astronaut going EVA, attached to a long boom. They then have to apply the material to the gouge, without knocking holes in the rest of the Shuttle tiles. The boom tends to move around a bit, and the underside of the Shuttle is surprisingly easy to damage. If the poor guy doing the EVA smacks into the bottom of the Shuttle, it could cause even more damage. So it's about as hard as applying glue to a crack on a delicate porcelain vase while danging from a rope 200 feet in the air. It's not impossible, but it's very difficult.

Re:Repair Kit?

[Robonaut]

NASA wants to make sure that attempting to repair the tiles is actually the best option. Up until post-Columbia, astronauts did not travel "under" the shuttle. There is a non-insignificant risk that the astronaut, robotic arm, or tools could impact the tiles and cause even more serious damage. When you factor in the inherent danger (although fairly minimal) in an EVA, add to it that there will be no visual on the space walker from the shuttle, the risks may not be worth it to fix what might be benign and superficial damage.

The folks at NASA understand the risks and they have already stated that foregoing a repair is only a risk to the shuttle that might require repairs on the ground.

Ol' Bricks and Wings

[Paulrothrock]

It's sad that we have to do this on EVERY launch when we had developed a perfectly good system where the heat shield was covered for the entire time it wasn't in use.

What, precisely, was wrong with the capsule system that necessitated the development of something that can *gasp* glide to a landing? How have we saved money by building a reusable craft when it costs a billion dollars a launch?

Re:Ol' Bricks and Wings

[geekoid]

"...was wrong with the capsule system that necessitated the development of something that can *gasp* glide to a landing? "

Size, risk, recovery costs. Well, when you calculate the cost of a single use capsule that can make deliveries to the Space Station, launch satellite, used to repair satellites, THEN you can do a cost analysis. Saying we have or have not 'lost' money compared to some non-existent thing, or that using a capsule wouldn't have cost more lives is a logical fallacy.

Re:Ol' Bricks and Wings

[scharkalvin]

At the time of its' design, the Space Shuttle made a lot of sense. The original concept called for full horizontal takeoff and landing with ALL parts being reusable. Due to cost over runs we ended up with the system we currently have. The original idea was to have an air breathing booster taking off from a runway which would fly up to the top of the stratosphere at which point it would switch to rocket power and climb up to a sub-orbital arc and release the orbiter. The 'booster-naults' would then guide the winged booster back to a safe landing at the 'cape while the shuttle would climb on its' own rocket power into orbit like now. The shuttle would need less rocket power to do this and the fuel tanks would have been self contained instead of external. Engine development on the shuttle would have been cheaper and the entire system would have been a lot more reliable. The problem was the cost of developing TWO space craft at the same time. The current shuttle made use of existing solid rocket technology (up scaled versions of the boosters used by the Delta rocket), and upscaled Apollo engines.

Re:Ol' Bricks and Wings

[Anonymous Coward]

A truly reusable space ship would be awesome. The shuttle was advertised as being one but it isn't.

Shuttle was supposed to take off like an airplane and land like an airplane. Then they had problems getting the design to work, so it wound up taking off like a rocket and landing like a glider made from bricks. It takes a really damn long runway to land a shuttle and you better hope you don't lose two tires on the same landing gear (I've heard it's pretty common to lose one tire, under the stress of landing; two would wreck the shuttle but wouldn't kill all the people on board).

The DC/X (lookitup on wikipedia) took off like a rocket and landed like a rocket, vertically on its tail. That design was safer: instead of plummeting at REALLY HIGH mach speeds, it controlled its speed and landed relatively slowly. Had that design been scaled up to a DC-1 we would have a much safer replacement for the shuttle.

The shuttle is an insanely complicated and expensive way to deliver a really large payload to low earth orbit. What we really need is a space "pickup truck" that can deliver a small payload to orbit, and do it over and over cheaply.

With airplanes, the most expensive thing is the fuel costs. With the shuttle the expensive thing is the "standing army" of people who have to service it between flights. We need something reusable that is designed to require less labor to service.

Re:Ol' Bricks and Wings

[MattHawk]

Even capsule design isn't a necessity to safeguard the heat shield from debris from the boosters. Mounting the reentry vehicle on top, rather than to the side, of the boosters would also have made the entire issue moot. It would still leave it vulnerable to bird strikes, but I don't believe the shuttle is moving fast enough to be significantly damaged by birds until it is well above the altitude you would find them. Of course, it's not a matter of "Just Stick It On Top", there'd be more redesign issues than that, but it's an example of another design paradigm that could have potentially proven superior to the one chosen.

Re:[AC]wrong

[everphilski]

It isn't momentum, again, it is kinetic energy that causes damage, KE = 0.5 * m * V^2. The velocity, squared, overcomes the density difference in short order. Again, go do some research on Columbia. It is consensus that foam did the damage.

April 10, 2007

[C10H14N2]

http://en.wikipedia.org/wiki/Soyuz_TMA-10

Re:April 10, 2007

[everphilski]

Charles Siymoni purchased a ticket on the Soyuz, which is lauched by the Russians.

Re:April 10, 2007

[goodmanj]

That's one small step for accuracy, one giant leap for annoying pedantry.

I didn't know

[Sunrise2600]

I didn't know that the spaceship was made out of styrofoam.

But is there a free standard?

[tepples]

When did NASA start using RealVideo? I thought they used to use standard formats. Is there a video codec that is nontrivial (not verbatim RGB), royalty-free (not MPEG-2 or MPEG-4), and recognized by a standards body (not Theora)?

Re:But is there a free standard?

[MobyDisk]

Is there a video codec that is nontrivial (not verbatim RGB), royalty-free (not MPEG-2 or MPEG-4), and recognized by a standards body (not Theora)? No, there are not. Therefore, they should choose a closed, proprietary, non-uniquitous piece of commercial nagware. If you can't do it perfectly, you might as well use the crappiest possible solution.

MPEG or MPEG-4 would be just fine since there are plenty of free, open, and reference implementations.
Flash video would be reasonable alternative because although it is closed, it's ubiquitous.

Re:[AC]wrong

[geekoid]

Don't try to explain physics to these dorks, they won't get it. Most of them consider /. the intellectual part of their day, right between belittling users and arguing if Batman could REALLY beat up Superman.

... and built by the lowest bidder (original?)

[argent]

OK, what's the original quote, and was it Shepard or Glenn? Or was this just too good a line for any of the Right Stuff mob to pass up?

"When reporters asked Shepard what he thought about as he sat atop the Redstone rocket, waiting for liftoff, he had replied, 'The fact that every part of this ship was built by the low bidder.'"

"I felt about as good as anybody would, sitting in a capsule on top of a rocket that were both built by the lowest bidder." (Senator John Glenn, Colonel USMC, Retired)

"It's a very sobering feeling to be up in space and realize that one's safety factor was determined by the lowest bidder on a government contract." -- Alan Shepard.

Re:... and built by the lowest bidder (original?)

[Volante3192]

...wasn't that Buscemi's character from Armageddon?

Re:... and built by the lowest bidder (original?)

[argent]

Ah yes, a character in a film released in 1998 is the source to a quote made in the early '60s. :)

If you have a time machine, I'd like to go back and pick up some stuff I left back in Australia before my parents got rid of it when they moved, and the Apple II Forth code that I lost when someone stole my backpack. Thanks much!

Re:... and built by the lowest bidder (original?)

[vertigoCiel]

Amost- he said that right before he lifted off, "I wasnt scared, but I was up there looking around, and suddenly I realized I was sitting on top of a rocket built by the lowest bidder." - Alan Shepard

Re:... and built by the lowest bidder (original?)

[argent]

That seems to be a more complete version, but googling for that I've found it attributed to Alan Shepard, Michael Collins, John Glenn, John Glenn quoting Alan Shepard, and a NASA tour guide named Mary Glenn quoting Shepard... which could have been the source of the John Glenn reference because the paragraph with the quote only contains her last name.

Where are you quoting from?

Re:... and built by the lowest bidder (original?)

[vertigoCiel]

I'm quoting from this Space.com article, which is Mary Glenn quoting Alan Shepard. I don't have a source for this, but when I was at Space Camp I was told it was Shepard who said this - and c'mon, Space Camp has to be on top of this, right?

Re:... and built by the lowest bidder (original?)

[Chris Burke]

I don't have a source for this, but when I was at Space Camp I was told it was Shepard who said this - and c'mon, Space Camp has to be on top of this, right?

Did they send you a bill for breaking their space station?

I know, lamest reference ever.

pfft...

[VMaN]

That'll buff right out.....

Re:[AC]wrong

[everphilski]

"if they ever fight, triangle wins, triangle man" -they might be giants

Columbia:

[Anonymous Coward]

"I've had worse"

Re:Roland

[Anonymous Coward]

Maybe they can patch it with Roland. His sacrifice will be noted. But the purpose of the tiles is to keep hot air out of the shuttle.

Russia is a European country.

[C10H14N2]

The vast majority of the Russian population is west of the Urals, making them Europeans by definition. Most of those European Russians are Slavic, which is by definition also European. So, you're right, a European purchased a ticket on a European-built spacecraft, launched in Central Asia by the Europeans who were the first to put a man in orbit, were the first to launch a space station and still hold the record for longest orbital habitation, which of course proves that only Americans can succeed at spaceflight.

Re:Russia is a European country.

[toQDuj]

not to mention the first to put a sattelite into orbit and a living creature into orbit. It's a real shame their moonrocket didn't launch properly.

Re:Russia is a European country.

[everphilski]

If you consider russians european, sure. the majority of russians do not.

Re:Russia is a European country.

[Anonymous Coward]

Rubbish. They're Antarcticans. Everyone knows that.

When can we decide what to read

[houghi]

Oh dear:

Roland Piquepaille writes We can mod comments up and down, but when can we start to do the same for submitters and/or editors?

e.g. people can now mod me down as troll or off topic, but I can not do the same to the above.

Re:When can we decide what to read

[toQDuj]

apparently I haven't been around long enough. What's the history behind this guy's infamy?

B.

Re:When can we decide what to read

[gkhan1]

I haven't been around to long either, but mostly it's because way back every third article that came through was from his blog and it was usually the same editor who posted them (can't remember which one). Often, the link was to his blog instead of the original article, i.e. it was him linking to something else in the way that most blogs work. This gave him a stellar google rank and people was accusing him of spamming slashdot to get more revenue to his site (and there was even some accusations that the slashdot editor actually was him).

I see it like this: if it's a good story, why complain. If it's a terrible story, complain about that instead.

Re:When can we decide what to read

[Fizzl]

The stories were/are always total bulshit. He has no clue about what he is writing about. He just spews out shit that sounds interesting but has no substance.
This particular article was interesting. He has just pictures and just couple of words but still manages to write bullshit. Namely, the pictures are nothing exclusive as pointed out elsewhere in the comments here.

Re:[AC]wrong

[E 99]

Well, it's not the kinetic energy of the projectile, it's the amount of kinetic energy that is transferred from the projectile to the tiles, which means things like hardness and elasticity play a part as well. Also, a whole lot depends on the size and shape of the ice. A thin sheet of ice is likely to get accelerated by air speed nearly as much as foam.

The same tile gash is here on earth too!

[Anonymous Coward]

They laser scanned? the tile damage and reproduced an exact copy of the damaged tile using some sort of CAM rig for study in a matter of 2-3 minutes.

Regardless of what one may think about what should be done they certainly have a lot of capability in terms of investigating the problem.

Looking to history the gash is nothing compared to many previous successful landings having much more damage (including whole tiles missing)

Re:[AC]THIS IS INSANITY!

[fiannaFailMan]

Whens the last time the Europeans have launched humans into space? *crickets* ...

Not sure about the last time, but the first European in space was a guy called Yuri Gagarin.

Right.

[C10H14N2]

They could consider themselves Brazilians but it wouldn't change the fact that they are primarily geographically, ethnically and linguistically quite certainly Europeans.

But yes, I grok what Bely was getting at, so can we move on?

Re:[AC]wrong

[dAzED1]

velocity might overcome the density difference in short order, but there's also the fact that foam will break off in large chunks, spreading out the area of impact (lessening the surface impact danger, increasing structural failure danger), whereas ice (can) break off in small chunks.

Even still, I've got other fish to fry today than trying to do a 3 factor comparison of that nature, especially when NASA scientists already did it and as you said, came to the conclusion that foam did it. ;)

solve the old fashioned way with a snowball fight

[viking80]

Lets solve this the old fashioned way with a snowball fight. Everyone on the 'foam is the cause' over to the left tile castle, and start throwing the foam balls. Everyone on the 'ice is the cause' over to the right tile castle, and start throwing the snow balls.

Re:AAPL to LOSE 20% by end of trading TODAY !!

[Anonymous Coward]

LIAR

One Word

[Hoi Polloi]

Spackle

Re:Roland

[MrNaz]

Or maybe it'll get patched on the second tuesday of the month.

Re:solve the old fashioned way with a snowball fig

[Orange Crush]

Lets solve this the old fashioned way with a snowball fight. Everyone on the 'foam is the cause' over to the left tile castle, and start throwing the foam balls. Everyone on the 'ice is the cause' over to the right tile castle, and start throwing the snow balls.

I'll play that game, as long as the entire castle is moving through the air at fairly low altitude and hypersonic speeds.

Actually, no I won't. But I'll still bet you foam hits harder than ice in those conditions.

"flying brickyard"

[flinxmeister]

I remember as a kid seeing the pictures of the early shuttle missions where many, many tiles were missing. IIRC, it was called the "flying brickyard". Can't seem to find any of those pictures now.

But it seems like our shuttle program is suddenly pansified. I mean c'mon...there's a difference between blowing a hole in the wing and a few flaky tiles.

Re:"flying brickyard"

[geekoid]

Yes, but since the disaster they MUST publicly scrutinized everything.

Don't forget Newton's Second Law: F=ma.

[Mr Z]

Don't forget Newton's Second Law: F=ma. It has strong implications on what happens when there's aerodynamic drag.

Air resistance is a force that's proportional to terms like drag coefficient, cross sectional area, and (the square of) relative velocity. It is not dependent on mass. Two objects that have the same profile, drag coefficient and so on will experience the same amount of force due to air resistance. Because they see the same amount of force, the one with less mass will experience more acceleration.

You can't ignore air resistance, since it's a much larger force than gravitational acceleration at these speeds. So, sure, the gravitational acceleration seen by two comparable chunks (one foam, one ice) will be pretty much the same, but it's far from the dominant term. In the context of ice and/or foam falling off the orbiter's fuel tanks, the foam develops a high velocity relative to the orbiter much more quickly than ice, because the ice accelerates much more slowly given the same force due to its greater mass.

--Joe

Roland the Plogger's "exclusive pictures".

[Animats]

Most of Roland the Plogger's "exclusive pictures" can be seen on the Neptec web site and other NASA-related sites. Someone commented on Roland's site, "Exclusive? Other than the fact that I've seen them on every news channel in the USA?"

The Neptec site is more useful, because it has the scaling info, showing how deeply the tile is damaged. The hole is through to the orbiter's skin underneath.

Re:[AC]wrong

[Anonymous Coward]

Noooooooo!!!!

I first heard that song about four years ago.

I finally quit hearing it in my head about a week ago and now this...

Particle man, particle man...

EAT IT ROLAND

[Anonymous Coward]

and your little dog, too!!!

throw some JBWeld on it and call it a day

[ArTT Vandelay]

and maybe a little duct tape for good measure

Where's the space?

[Anonymous Coward]

Somehow I feel that NASA's (wo)manned missions are long dead. Nowadays they spend more money and time examining their own machinery than examining the space.

Re:Where's the space?

[east coast]

Nowadays they spend more money and time examining their own machinery than examining the space.

While I'm sure the holes in the tiles of the shuttle is not part of NASA's plan I think it's actually a very useful part of the mission.

We need to get beyond this whole concept of sending up the best and the brightest and throwing gobs of money at the program. We need to get to the point where we will have establishments (most likely lunar at first) where we're going to have real workers and not just high end engineers.

The idea of doing maintenance in space is going to be part of this future colonization. Being able to know how to do real work in this environment is going to bring us much closer to those goals. If we're yanking people out of a space station or colony every time the slightest maintenance needs done we're going to be paying big bucks with little return.

The lessons learned with the tiles on the shuttle and the heavy maintenance schedule of the Mir are going to take us a long way in establishing real working environments instead of just clean room type experiments.

Re:Where's the space?

[PingPongBoy]

We need to get beyond this whole concept of sending up the best and the brightest and throwing gobs of money at the program. We need to get to the point where we will have establishments (most likely lunar at first) where we're going to have real workers and not just high end engineers

The definition of alien has come full circle.

The next step is to be able to send more people and keep them longer out there. They all have to be smart, principled, dedicated, and team players. Perhaps the education system is what needs to be prodded to turn out better people at all levels so that there's no shortage of people to do the heavy lifting. An education system that strives to produce an average grade at B- or C+ levels has got to be missing something.

Several of my professors mentioned that their target average was 70%, which is enough people passing to be a success but the average person wouldn't be spectacular. It's understandable to set a high bar so that it is a meaningful challenge, but it's also perceived that the teaching cuts corners in terms of quality so that some students fall behind while teaching workload is reduced. When one thinks back, there were a lot of poor presentations in the classroom.

I consider myself to be fairly smart, and I learned many things on my own to get good marks. These days it's not so hard to find all the knowledge required for a degree in sources close at hand - books and Internet - rather than in school. Perhaps the best and brightest should be motivated to view school as a secondary source of education and given the chance to earn their qualifications in a more compressed and streamlined path. School involves a huge amount of repetition and inefficiency that may well weaken student's views of themselves as it teaches tolerance for lower performance.

In space, a person needs to be able to operate independently as well as together. School makes people go in lockstep as much as possible due to economic restrictions. There's not enough personal guidance, and that may be the biggest factor in helping people succeed in all the typical careers. If a nation is powerful enough to defy gravity, it should educate people to have the qualities desired in astronauts.

The reasoning of NASA engineers?

[spirellis]

I don't specialize in fluid or thermodynamics but this is my opinion, and any support/rebuttal is welcome!

A quick check on re-entry temperature variation on this site: http://www.columbiassacrifice.com/$D_temperature.h tm shows the area around the hole endures about 10 minutes of 1500 deg F heat, and Google tells me aluminum melts at 1220 deg F. On the surface (pun intended), this would seem cause for concern.

If NASA engineers feel these tiles can re-enter without repair, their reasons could be:

1) This area of the shuttle does not have to contend with the extreme heat that is experienced at the nose or other leading edge surfaces so the "hot air" isn't hot enough to melt the aluminum in the belly, and
2) The hole must be small enough that hot air flow may "skip" over it on re-entry. If the hot air can indeed passes right over it, then the danger to the aluminum inside is probably not very great.

If the engineers ran a "simplified" mathematical simulation assuming the hole was just the "average" well-formed hole, the above rationale would make sense.

I think the more important concern to focus on (which I'm sure NASA must have considered), is that this hole is very asymmetric. The photos provide terrific evidence. One side the gash slopes gently into the "hole" (I presume where the depth sensor reads 1.2 inches, since the tiles are only 1 inch thick), and on the other side, you have a quarter ping-pong ball cut-out as well as a 90-degree lip of half-tile above the hole. In this instance, I think the direction of travel of these tiles on re-entry matters a great deal... I think the first scenario below may be most cause for concern.

1) If the "up" orientation of the tile lettering is the shuttle's forward direction, I would imagine the hot air flow will not be turbulent upon entering the gash, and will actually follow the gentle slope downwards towards and into the hole, melting what is inside. What hot air doesn't make it into the hole will smack into the 90-degree lip and the quarter ping-pong ball cut-out, causing excess heat at those edges and/or loosening that tile from its backing, causing it to fall off (though not too likely since that lip represents only a small portion of that tile, and it is buttressed by the other tiles "behind" it).

2) On the other hand, if the forward direction was reversed, the hot air flow would become turbulent upon meeting the quarter ping-pong ball cut-out. If the dimensions of that cut-out are sufficiently disruptive, the turbulent hot air could "lick" the hole, melting whatever is inside, what doesn't go into the hole will glide off the sloped ceramic gouge on the other side. With the turbulent air, there will be a negative air pressure around that tile, but the force shouldn't be enough to rip the tile from its backing.

If the shuttle direction is that of option #1, let's hope that hole is small enough that as litte hot air gets in as possible.

My point is this: A hole is not just a hole unless it looks the same from all sides...

Re:The reasoning of NASA engineers?

[geekoid]

They have landed the shuttle with missing tiles before.

I will let you ponder what that means.

Re:The reasoning of NASA engineers?

[danlock4]

missing tile != small gouge in tile

I think the depth of the gouge is more significant than the size of a missing tile or tiles.

Just food for thought...

Re:solve the old fashioned way with a snowball fig

[viking80]

Since the snowball fight is not sufficient to convince you, as it was to my 5 year old son, I'll do the physics:

From http://spaceflight1.nasa.gov/shuttle/reference/bas ics
It actually goes supersonic at about A1=8500 m, and hypersonic at A2=50km altitude. aerodynamic load at A2 is similar to 140km/hr at sea level.

The force on a foamball or snowball will be the same. The foamball will impact with a higher speed, but the iceball will spend more time in the airstream, gaining much more momentum, so what is worse?
Since v=2as, F=ra, E=1/2mv^2 where v is impact velocity, a is acceleration and s is distance it is falling before impacting. F is aerodynamic force and equals density r, times acceleration (For a unit size piece). E is impact energy.
Solving for Energy E=2rF^2s^2. Only density is a variable. The rest is constant, so we revrite as

Impact energy E=kr, where k is a constant, and r is density. So ice is worse than foam.

Exclusive eh?

[Anonymous Coward]

I think I saw these photos on "Am I hot or not"

Columbia:

[Anonymous Coward]

"Went right through the meat"

Re:[AC]wrong

[cayenne8]

"Particle man, particle man..."

If that is bothering you, then, just 'make a little bird house in your soul'...

:-)

You spelled 'vial' wrong, genius

[Anonymous Coward]

only on /.

Re:solve the old fashioned way with a snowball fig

[david.given]

E=1/2mv^2 ... Solving for Energy E=2rF^2s^2.

Are you sure about that? I can't see any way for the m to get cancelled out.

When I figure it out, I get:

density r = m (assuming unit volume, as you are), acceleration a = F/r, therefore a = F/m;

impact velocity v = 2as, therefore v = 2FVs / m;

impact energy E = 1/2 m v^2, therefore E = 2 F^2 s^2 V^2 m^-1.

F, s and V are all constant, as you point out, which makes the only factor the inverse of the mass. Which makes intuitive sense; energy scales with the square of the velocity, and a light object will be moving faster than a heavy object.

I'm not sure whether adding in the 3g shuttle launch acceleration would make a difference to this.

f-ed

[Anonymous Coward]

f-ed fo'sho!

Rush? Truth?

[Anonymous Coward]

"Pills" Limbaugh wouldn't know the truth if it was written on his fat forehead in cheez whiz.

Alls I needs is

[syrrys]

My trusty rocket-boots and a big ol bucket o' paper mache. I'll fix 'er fer free. Just lemme keep anything I find out there. The guy two trailers down from me is always bragging about the time he got hit in the head by space junk. I want my whole front dirt covered with it!

The humans are the cheap side...

[Anonymous Coward]

It's the shuttle loss to be worried about; we have more people than we need. Shuttles, however, are irreplaceable.

That sounds harsh, perhaps, but it's true. Once you get past the emotional aspect of it, if we lose this shuttle, the fleet is lost, and we'll be out of the manned space business for 10 years.

Re:solve the old fashioned way with a snowball fig

[shellbeach]

density r = m (assuming unit volume, as you are), acceleration a = F/r, therefore a = F/m;
impact velocity v = 2as, therefore v = 2FVs / m;
impact energy E = 1/2 m v^2, therefore E = 2 F^2 s^2 V^2 m^-1.
F, s and V are all constant, as you point out, which makes the only factor the inverse of the mass. Which makes intuitive sense; energy scales with the square of the velocity, and a light object will be moving faster than a heavy object.
I'm not sure whether adding in the 3g shuttle launch acceleration would make a difference to this. Can we please just go back to the snowball fight? At least it was funny ...

time for a new aproach?

[razpones]

How about putting those tiles, (or others of better quality), all over the space ship?, it seems as if you put them on the top side as well as the under side there is an option at re entry to flip to the undamaged side (and its more likely to be undamaged since that side won't get ice projectiles from the main tanks). Just a thought.

NASA and the USA....

[Twoshane]

Hmmmm the USA has a brain damaged scumbag junkie for a president. It's corporations rob the world. It's military are just low paid gun toting hacks for the corporations. It's media are stupid enough to work for the bucks and not the principles. And it's shuttle is an over priced piece of junk. The Next American Space Race will be with a bottle, a rocket and a box of matches. Duhhhhhhhhh. Most Americans in chatrooms are just wankers anyway.

patch

[whitroth]

My wife, an engineer who worked for 17 years at the Cape, on both Station and Shuttle, and is *very* familiar with the tiles, says that she thinks they should stick some stuff in there. What worries her is that it's at the joint.

                mark

I saw a tile demo once...

[LanMan04]

When I was a little kid (9 or so), I had to opportunity to go to Space Camp at the Cape Canaveral facility, where we got to participate in this great shuttle tile demo.

The demonstrator had a tile held in place by a little jig/stand, and had a hand-held blowtorch going full-blast on one side of the tile (I forget if it was propane (3600F) or MAPP (5300F), but it was hot, regardless). Us kids were invited one by one to touch the other side of the tile with our hand, which was room-temperature (or maybe *slightly* warm) to the touch. I do remember they guy saying not to *push* on the tile at all, just feel it, so maybe they do break really easily. Or maybe this was an older type of tile than the ones they use now? Just thought I'd mention it.

Objection Your Honor

[Anonymous Coward]

"Of course their Soyuz workhorse is a totally different and more efficient design."

Objection your honor. While clearly the Soyux is totally different, "efficient design" is made without facts in evidence, nor is the witness qualified to make such a remark.

I move the statement be marked "talking out of his ass".

Re:Roland

[Anonymous Coward]

I have definetely read this somewhere yesterday, before that asshole posted it to slashdot. though of course I can find it now since all the link whoring buried what I think was an earlier source deep inside the internet where google will never find it.