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NASA Finds 4-5" Crack in Shuttle Insulation
PresidentKang writes "Spaceflight Now is reporting that a large crack has been found in an external tank foam of Space Shuttle Discovery on the launch pad. According to the article: "Engineers inspecting the shuttle Discovery's external tank following Sunday's launch scrub found a crack in the tank's foam insulation near a bracket holding a 17-inch oxygen feed line in place. Some engineers believe the crack must be repaired but senior managers say a variety of options are on the table, from fly as is to making repairs.""
"...but senior managers say a variety of options are on the table, from fly as is to making repairs."
I wonder what those managers would say if they had to fly the shuttle.
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Did they get posession charges or was there enough crack that they got booked for traffiking?
So now the real question becomes, which will launch first, DNF, Windows Vista, or the Shuttle? I say the Shuttle, it's cracks aren't nearly as big as Vista's (an M$ product) will be.
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Surely they should just get the thing working before they add extra features like that?
If we can put a man on the moon, why can't we shoot people for Apollo-related non-sequiturs?
I know the shuttle is at the end of life, but the follow on will still need insulated tanks. The early Atlas had no insulation and needed to be fueled in the final minutes of the countdown. Clearly a problem. But any means of making the insulation crack free, thus flexable, and still able to withstand the launch, thus stiff, would require significent added mass. Mayby an outer shell of carbon composite.
Not an engineering project or a business enterprise.
This type of thing is to be expected in political endeavors. Their purpose is never to satisfy the stated goals but to advance constituencies political agendas. For a political project failure is not only an option but often the most desirable one.
Fix it later? Aren't they running out of time before the July 4th launch? Wrap it in duct tape... that seems to work well for other insulated pipes installed at public institutions (at least from my observations).
Does anybody at NASA have a working memory? Don't they remember the results of the Challenger inquest, wherein plenty of evidence of engineers saying "DON'T LAUNCH! BAAAAD!" was ignored?
I fear we may very well get a "fourth to remember", and NOT in a good way! It is all very well for a bottlerocket to explode in flight, NOT A MANNED SHIP!
I fear that NASA is going to launch, come hell or high water, and damned be the consequences.
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If you can't take a little bloody nose, maybe its time to go home and crawl back under your bed. It's not safe out here. The galaxy is wonderous -- with treasures to satiate desires both subtle and gross -- but it's not for the timid..."
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On the one hand, shuttles flew forever shedding foam and it only became a real problem when a large enough piece tore off to actually damage the shuttle in flight significantly. Engineers accepted the risks with many reservations, because damage was never really that severe. Of course hindsight is 20-20 and this problem could have been rectified if the foam was located interior to the tank as opposed to externally. I think they were worried that if they tried that, there would be voids in the insulation that would allow heat to enter and cause problems, but that was a manufacturing issue which probably could have been resolved with a little ingenuity.
On the other hand, a 4-5 inch crack is nothing to sneeze at and with the aerodynamic forces that batter a shuttle on its way into LEO, any number of things could cause that crack to widen and eventually spilt, teraing off a really large section of foam. It has to be repaired; I don't see how NASA management can ignore this. If they do, and the shuttle is damaged or heaven forbid, destroyed, that's the end of the space program. And probably rightly so. Like to many things, NASA was created due to Cold War concerns, namely that the Russians were going to grab the "high ground" of space and show us up in technical endeavors, weakening our position on the world stage. Like other Cold War relics, it too either needs to change or be dismantled.
I'm a NASA booster (forgive the pun) -- my dream from childhood was to walk on the Moon. But I can say that I find it hard to trust the NASA I see now; it has become hamstrung by indecision, beaureaucracy, and lack of imaginative leadership (with apologies to Dan Goldin, Sean O'Keffe, and Mike Griffin). I wanted John Young to become NASA Administrator -- tough talking, smart, no-nonsense, and imaginative. He might have (and still could if he wanted the job) lit a fire under NASA and got them thinking straight. The problem is, NASA was not prepared for life after Apollo and it shows. The STS was a compromise (no engineer in the early 70's thought solid rocket boosters were a good idea) and a poor one at that.
I think a) NASA needs to be saved from itself and b) the American people have to learn what a truly great resource they have in their space program. Barring either of those, it will be up to private industry to carry the torch.
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Well they've fueled the Shuttle twice already, Tuesday will be the third. Thermal stress was indicted as a contributing factor in foam detaching. Everything probably would have been fine if they had launched the first time, I suspect their cloud distance tolerances are too tight these days compared to thermal stress from fuel cycling on the parts for later lift off.
I'm not saying NASA should have launched the first time, but with only a 30% chance of launch due to weather, why did they even fuel the bird up? Weather should have a least an 80% chance window I would think think to decrease the likelihood of one fueled up scrub after another leading to excessive thermal stress on tank components.
Also while many may see July 4th as a feel-good day to launch (National pride and all that) if anything goes wrong there are religious types both Christian and Muslim that will see it as a sign validating whatever their view of the world is.
Letter To Iran
When I was studying at Fermilab, Osheroff [link to:http://en.wikipedia.org/wiki/Douglas_D._Osherof f] gave a lecture about the Space Shuttle Columbia. He was selected to head up the review panel, and I'm pretty sure that I remember hearing that the foam was almost certainly the cause of the explosion.
Seems like an unwise decision to let it run without repairing it even if it is unlikely that anything will happen, no?
Mission control: "Astronaut this is mission contol. We have a problem. Over."
Astronaut: "Mission control this is Astronaut. What is the problem. Over."
Mission control: "Astronaut we're looking at the live biosigns from your transmitter and have come across a concern. Did your mother drop you as a child? Over."
Astronaut: "I don't believe so. Why? Over."
Mission control: "Because..."
*general snickering from mission control*
Mission control: "Because there's a big crack in your butt! Over and out."
I'll be your candy shop of infinite deliciousity if you'll be my discotheque of endless rump-shaking.
Wellll....
..but that isn't the connection he was going for I think. The connection would be God giving the Americans a bloody nose on the day that is their nation's pride day. The significance of it wouldn't be the religious properties of the day, but the secular one.
7 is heavenly perfection, and July is the 7th month.
4 is earthly perfection, and it's the 4th day.
NASA commited itself to solving the foam problem but when it turned out to be difficult they decided they didn't have to solve it. So they found evidence that the problem wasn't solved. How could this be in any way surprising?
Because in Florida (I live here) it doesn't matter what the weather report says, there's always a 50% chance of rain. I gave up listening to the weather reports long ago.
The only time they are right is when they say 'It's raining right now' or 'It's sunny outside.' We don't even need dark clouds for rain, lightning, or both. Sunny showers are not that uncommon.
In short, 30% is just as good as 80% here.
Oh, and btw, if the weather report says 'in 12 hours, a hurricane will hit your town' you can safely sit at home and eat popcorn. It's not going to hit you.
"If you make people think they're thinking, they'll love you; But if you really make them think, they'll hate you." - DM
I remember some anecdote about Gandhi. Someone asked him how come his stance on something is now the exact opposite of what it was last week. Gandhi said something like, "because this week I know better."
Now I'm no Gandhi, but I can think of a lot of situations when learning something new made me reverse my stance on something. In fact, I consider it to be what every sane human does all the time. Only zealots have one absolute truth and stick to it for ever, no matter what. A scientist (either theoretical or engineer) should have no such things by definition. If you learn some new fact, or do another calculation, or run another simulation, or whatever, and it contradicts what you previously believed, yes, as an engineer I'd _expect_ you to be ready and willing to change your mind about it. Maybe you'll run some extra tests, do more calculations or whatever first, that's ok, but you shouldn't ever have the last week's stance as something set in stone and unchangeable for any reason.
So, well, I won't argue a your point B for lack of enough data, but point A leaves me scratching my head in disbelief. So someone decided that those engineers aren't trustworthy... because they changed their mind? Seems like a pretty weird attitude. I definitely expected that at NASA even management would be a bit more open-minded than that. They're pretty much one continuous experiment and using experimental equipment, so it's exactly the kind of thing that should be _expected_.
We're not talking stuff like designing a bike, where you can just do it all by the book and know the same today as you knew last week. We're talking crazy experimental stuff that noone else has done before, and a lot of it is tried for the first time. Someone calculated that this valve should be perfectly safe, or that foam can't break this time, but essentially it's the first time anyone actually put that valve or that new foam on a rocket and blast it into space. There's a lot of stuff that could act differently than in the simulation, or than in whatever lab tests were done.
So, yes, stuff like someone doing some new calculations and deciding, "teh oops, this thing is gonna blow up" are the kind of thing I'd _expect_.
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Here are the slides and video from the talk. It was one of the good ones.
The problem with religious fanatics (and anyone who takes Revelations seriously is a fanatic), is that they will use any evidence as a validation of their delusions. It would be pointless to worry about such people.
Just last night there was a program broadcast on DayStar (a christian tv station) in which a preacher and his obviously strung-out-on-drugs assistant were showing clippings from newspapers, then reading passages from the bible, and crying with joy as they showed this proof that "the rapture" is near.
And yes, I watch that station because it makes me laugh more than comedy central. Good stuff.
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GP makes sense, but is not right. Note: I'm not an authority on the Shuttle program by any means, but this is just basic science. What I'm saying below is even more true for the hydrogen, but I used the oxygen as an example. There are two basic reasons it would be quite cold.
1. To make Liquid Oxygen at room temperature does require extremely low temperatures. But they aren't keeping it THAT cold, because it would be prohibitively difficult.
It doesn't need to be that cold, because under pressure the temperature where it stays liquid goes up. You can keep a strong tank of O at room temperature and it will still be liquid. So they likely keep it cold to reduce the pressures they have to maintain somewhat, but it's not required.
2. Whenever you reduce the pressure on a gas (or especially when a liquid becomes a gas) this is a very endothermic (heat absorbing) process. So a home oxygen tank IN USE is cold, but one being stored isn't. (Random metal at room temp will FEEL cold, but the tank isn't _especially_ cold)
When you pour the liquid oxygen into a large temperature tank - even if you do it really fast and in a sealed way - any room left in the tank instantly becomes filled with much higher-pressure gaseous Oxygen. This expansion makes it very cold. And there is a lot of room in the tank when you START filling, even if by the end you filled it all.
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Thanks very much for that response. I was going to write something very similar as soon as I returned from lunch. Had the GP even looked at the article in question, he would've seen that in the first paragraph Tufte mentions that this bullet-point presentation culture was witnessed and commented on by Feynman after Challenger. Since then, however, PowerPoint has worked it's way onto just about every single corporate/office/government/whatever desk in the world. It's not particularly a problem with the software itself (and hence not MS's fault at all), but rather the way in which people use the software for purposes that it's not well suited.
This guy's the limit!
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"Oh, and btw, if the weather report says 'in 12 hours, a hurricane will hit your town' you can safely sit at home and eat popcorn. It's not going to hit you"
Unless they also say "the levvies will hold", in which case, you know you're in trouble
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That issue is addressed in the essay as well (the link above is only a 3 or 4 page excerpt from the 30 page essay). Tufte makes mention of how many students are being taught to prepare a 7 or 8 slide presentation on a topic. Of those slides, there are maybe 10 words or so on each of them. Total time to sit down and silently read through the slides: under 30 seconds. Total time that the student spent preparing the presentation: 1 week.
This guy's the limit!
Either way, the STS needs to go. It's 30-year-old technology, is not truly reusable, and can't do anything at all out of LEO.
We can do far, far better. End the Shuttle program, put the orbiters into museums, and put its operating budget into R&D for a new spacecraft.
+++ATH0
Sorry to piggyback on a joke. This is the actual status, copied from NASA's shuttle page
It sounds like "crack" isn't a very descriptive term. A small piece broke off, probably due to the weather-related causes. They're trying to decide if they need to erect a platform to do a hands-on inspection.
On the source page there's a picture that took me a minute to figure out, so I'll explain it. The solid orange to the left is the main body of the external tank. The round orange vertical item in the center of the picture is the LOX feed line. The big metal piece is probably part of the tripod mount. Just below and to the right of the mount is one of the brackets that holds the LOX line in place, covered in foam. Looking closely, you can see a little triangle of white where the little chunk (about 4 long) of foam spalled off. I assume the T-shaped feature to the right of that is the so-called ice/frost ramp, which they're concerned may be at risk for falling off in flight. It's much clearer in the high res picture linked on that page.
At first glance, it doesn't look like a concern at all, but obviously NASA wants to make sure of that. If anybody has serious reservations, they'll setup a platform to get somebody who knows what to look for up close to it and look for evidence that this may increase chances that the ice/frost ramp or other pieces of foam may fall (smaller cracks, loosening of the frost ramp, etc).
For comparison, this piece of foam is estimated at 0.0057 pounds and may be as large as a cellphone. The piece that struck Columbia's wing weighed an estimated 1.67 pounds and was described as "briefcase-sized"
(Also, the joke is 2nd Tuesday of next week. Your rendition makes about as much sense as a screen door on a battleship)Soyuz has an ablative heat shield. It's probably made of some sort of ceramic, formed into 8 layers called "blankets" (I think they're only flexible enough to allow for expansion and contraction of the spacecraft, not like a quilt). The capsule is single use, so the heat shield only needs to survive one re-entry, and the exposed surface area is small, reducing overall weight. The ablation (burning away of small particles) carries heat away from the capsule. A similar system has been used on pretty much every entry system except for the shuttles, even the Mars rovers. The Russians did use a system nearly identical to the space shuttles for their Buran shuttle, which was abandoned after one flight due to budget problems.
The weight and maintenance of an ablative heat shield were prohibitive in a very large reusable system like the shuttle. Instead, the leading wing edges and nose of the shuttle are protected by reinforced carbon-carbon tiles, the underside by ceramic tiles that are in some ways similar to aerogel, and other sensitive areas by a heat resistant cloth. The carbon-carbon is the most effective and actually pretty strong, but about 6 times more dense than the other options. Read more.
In short, no the Russians haven't had fatal problems with their thermal protection, but it's not feasible for a vehicle like the shuttle.