Aces High Bulletin Board
General Forums => The O' Club => Topic started by: maxtor on February 07, 2003, 02:08:39 PM
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http://www.aviationnow.com/avnow/news/channel_awst_story.jsp?id=news/shuttle2_news.xml
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Gotta wonder why NASA was so quick to reject the idea that the foam debris may have damaged the wing.
ra
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Yea just finished reading that a while ago...leading edge problems...I'd love to see the pics that telescope took.
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The foam insulation is the consistency of styrofoam. Thats why. Only way it could have damaged the shuttle is if it was covered and encased in ice.
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Originally posted by ra
Gotta wonder why NASA was so quick to reject the idea that the foam debris may have damaged the wing.
ra
Doesn't sound like they've discounted that quite yet:
Columbia reentry accident investigators are also trying to determine if, as in the case of Challenger's accident 17 years ago, an undesirable materials characteristic noted on previous flights--in this case the STS-112 separation of external tank insulation foam debris--was misjudged by engineers as to its potential for harm, possibly by using analytical tools and information inadequate to truly identify and quantify the threat to the shuttle. As of late last week, NASA strongly asserted this was not the case, but intense analysis on that possibility continues.
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Originally posted by davidpt40
The foam insulation is the consistency of styrofoam. Thats why. Only way it could have damaged the shuttle is if it was covered and encased in ice.
Piece of styrofoam can kill you in a hurricane strength wind...the shuttle was 79 seconds into flight when the foam came off, far greater wind speed than a hurricane.
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Even in hurrican strength winds, I doubt styroforam has the momentum or kinetic energy to do much damage at all.
A brick sized piece of styrofoam weighing 2.5g compared to a brick sized...errr... brick weighing 2000g would have to be doing 800 times the speed of a brick to have the same momentum at any particular speed. Also, the foam deforms much more readily and as such can dissipate the energy of a collision.
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Dowding, you want me to post the picture of a piece of straw embedded in a Palm tree from a hurricane?
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If that straw hit that tree sideways nothing would have happened. I thought the styrofoam hit right after launch and the first few seconds the rocket isn't really going all that fast. So where did the foam come from? Is it part of the engine? Maybe I ought to read that link when I get the time.
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<>>
From 2 days ago:
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"It does not make sense that a piece of (foam) debris caused the loss of Columbia and its crew," Dittemore added. He reiterated Columbia tried to compensate for increased drag on its left wing in the seconds prior to its breakup, firing steering jets to right itself. But Dittemore said of Columbia, "It was doing well, but it was losing the battle." >>>
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A good link about the "Politically correct" foam they used:
http://www.foxnews.com/story/0,2933,77832,00.html
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I believe that could happen. The end of a piece of straw has absolutely tiny surface area. The pressure it would exert at extremely high velocities would break the surface of anything that had even a little give in it.
I doubt pieces of foam would have such a small surface area. I also believe hardened ceramic tiles are not very like palm trees at all.
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ra, the news is pretty much putting the spin on the foam not being looked at.
In an investigation, such as this, you work from the point of failure backwards to determine the probable cause and until that investigation is complete, everything is speculation.
NASA would be irresponsible to claim the foam block caused the failure until they have the data to prove it.
While the foam block appears to be responsible for the damage. What kind of damage did it do? How did it do the damage? Were there other factors that the foam impact exacerbated?
Solving this problem requires answering far more questions, if it is to serve to protect other astronauts from future problems.
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I disagree that it was foam insulation fromn the tank, but more likely a massive hunk of ice that fell from the bipod supporting the orbiters nose on the external tank. And those of us that live where it gets cold, know that ice is as hard as a rock.
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Yes, but Dowding, the leading edge of the shuttles wings are not ceramic. They are a carbon material with insulation behind them mounted in a manner that allows them to float a bit.
If the foam impact caused some level of structural failure of the seals between the carbon coverings, then wing failure could occur as heated plasma would quickly erode through the actual wing surface.
Would not take much of a leak for that to happen either.
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Didn't know that. Is the foam a new addition to the shuttle set-up? Either way, I'm sure the guys at NASA would have looked into the potential damage caused by insulation and ice hitting part of the shuttle.
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Well, whatever it is- it didn't necessarily have to damage any of the tiles to cause catastrophic wing failure on re-entry.
It just needed to make a lil gap between the tiles to do the whole thing in, cuz you basically got yourself a welding torch coming in a small gap that will melt the wing from the inside out.
-SW
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The foam was changed to another compound to meet environmentalists concerns.
Foam breaks loose in every launch and has hit the shuttle before. The shuttle also loses tiles and has managed to always land safely. However, those tiles are always above the black bottom tiles.
I do not know of a shuttle that has lost a black botton tile.
I think something caused a disruption/distortion of the leading edge of the left wing, which is not ceramic and that distortion lead to the eventual failure. Whether the foam caused it or not is yet to be proven.
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all it (something shattered against bottom of left wing at takeoff) had to do is knock it (tile) alittle loose or crack it or that particular tile be installed incorrectly....
doubt the exact cause will ever be determined
nothing is perfect in an imperfect world
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True. But it's hard to believe the shuttle is that fragile. It has to do a good impression of a controlled meteorite - that's a tough act. The technology has been tested to near destruction (and unfortunately, past it) over the years.
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I doubt pieces of foam would have such a small surface area. I also believe hardened ceramic tiles are not very like palm trees at all.
Give'm hell dowding!
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It's actually pretty fragile if you take it out of its operating envelope. Most flying craft are.
The shuttle was not designed for direct impact of any type. The air frame is tough enough to stand the repeated G-forces of launch and re-entry, but the covering is pretty flimsy.
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Yeah, that was quite an obvious statement. But it was meant to be. ;)
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""I also believe hardened ceramic tiles are not very like palm trees at all.""
the tiles on the shuttle are not "hardened" like floor tiles , they are a ceramic "foam" and not very strong, the tiles are not structural , they are to insulate the ship from the high temps on re-entery.
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I get the impression people think the foam on the space shuttle has the same weight/density as packing foam...
There's insulation foam out there hard as a rock, and if you peg someone with it, there's a good chance you'll knock them out.
-SW
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SeaWulfe, the source I read said that the insulation that hit the shuttle had the same density as styrofoam.
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The foam insulation is the consistency of styrofoam. Thats why. Only way it could have damaged the shuttle is if it was covered and encased in ice.
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saw an interview a couple days ago where they where holding a peice of the 'foam'. it looked alot more like a piece of cynder-block than styrofoam. they had a couple peices in their hand and tapped them together. made a clanking sound that was a lot more like 2 bricks hitting each other than a mushy sound of styrofoam
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Originally posted by ra
Gotta wonder why NASA was so quick to reject the idea that the foam debris may have damaged the wing.
ra
There are a number of reasons why NASA wants to reject the idea of wing damage from foam. One reason is that there have been many similar incidents of foam damage prior to last weekend and none have resulted in structural breakdown. Also there are a number of new theories that NASA is investigating that aren't "media friendly" (not easy to explain in lay terms).
I work with the re-entry simulations team at the Air Force Research Labs at Hanscom AFB. Up until yesterday we were modeling enemy missile signatures. Yesterday we got word to drop everything and help support the investigation. The theory that we're looking into is that there was a piece of space debris lodged into the body of the shuttle (normally harmless). There is also data suggesting that there was a local ionospheric sprite that occurred shortly before the shuttle broke up (also, normally harmless). However, there is radar data suggesting that this sprite may have traveled up the plasma trail left by the debris and struck the shuttle.
Our job is to simulate the plasma sheath around the shuttle to determine if it would have been conductive enough to carry the sprite. We're also going to try to model a perfect wake radar cross section to compare it with last weekend and previous flights.
It may yield results... it may be a dead end.
Believe me; NASA is pulling out all the stops on this one. Don't believe everything that the science correspondent of your local news station says. There are a lot of really good people working this and the problem will be solved.
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But the shuttles lose tiles all the time.
I'm not going to pass judgement and say anyone is right or wrong, but I will let th experts work this one out.
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ra, the news is pretty much putting the spin on the foam not being looked at.
The quote I pasted was from one of their spokesmen. He was stearing reporters away from the idea that the foam could be the cause. It would have been more clear if he had just said 'we aren't ruling anything out'.
ra
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I know ra. NASA started out with telling news folks they weren't ruling anything out, but the news hounds keep pushing.
I am surprised the news relations guys for NASA have not started walking out and tossing grenades into the idiots.
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NASA has access to grenades???
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The tragic thing is this prolly could have been prevented just as challenger could have been prevented. NASA had on thier managment hats again. Report I read some where yes the insullation has broken off before and cause minor damage but it would have cost more and been more dangerous to send a man over the side to check then if we just brought them down normally. Besides there was no way to fix it if it had been broken. Cost efective has no place in something as dangerous and unforgiving as space exploration. The lives of seven of the best this planet has to offer what price is that worth? I cant count that high maybe NASA managment can.
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Roger that Icemaw. I think NASAs main problem is that they are on a budget, and space exploration is not the main priority of the U.S. Sometimes it pays off to take calculated risks. Nasa knew there were a 30inch by 14inch gash in the tiles on the left wing two days before re-entry. But would it have been worth it to send another shuttle up (something never done before), to fix a problem (that had never caused a problem on re-entry before) in an environment where shuttle repair had never taken place before? That emergency repair flight would have perhaps cost NASA the equivalent of 10 or so shuttle launches, and the project managers would have come under intense scruitiny because shuttles land with missing tiles all the time.
But NASA screwed up and got the entire space crew killed, for the THIRD time (apollo 1, challenger, and Columbia).
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Someone on Foxnews computed the speed at which the foam would have struck the wing at, since the foam only travelled a few feet, and both objects were being propelled at the same speed, etc etc (insert fancy physics talk)...anyways...according to these scientists, they computed that the foam would have hit the wing at a speed of 66 mph or so, given the distance and such from when it sheared off, to impacting the wing.
Now, I guess the other question is, would a 65 mph piece of 2 inch foam jolt loose a heat tile or other part?
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I have read 2 articals on NASA sending out a crewman to see the damage and also sending up another shuttle (Atlantis is ready to fly again). They said for safety reason 1 no jet packs on board or no robotic arm to use either they could not send a crewman out.
They said operating 2 shuttles so close together would be highly dangerous.
Columbia was not equiped to go to the space station and doc there nor did it have the fuel to get there. NASA does not have a shuttle repair plan.
NASA is also very picky about the weather if iceing conditions existed then they wouldnt have launch. I do know the stuff in the tanks can cause iceing to take place.
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I think NASA is deemphasising the foam strike so that they can try to gather as much evidence and thouroughly examine as much as possible before theorizing.
Some of the problems of the tile repair scenario:
The shuttle bottom surface has nothing to hang on to.
You would need some sort of scaffolding so that a spacewalker could exert the necessary forces for the repair.
All the tiles are specifically designed for each placement.
You would have to develop some sort of bondo that would fill the void of a missing tile with most of the integrity of the original equipment.
If a bondo could be developed, does it cure in vacuum?
Perhaps you whittle a new tile out of a chunk of stuff on board. Does the adhesive work in space?
Does it cure in +/- 300F?
Does the repair cure in time, before the crew oxygen depletes?
Need to get a little ROV for flying around the shuttle to do reentry inspections.
If it had been known Columbia was damaged, would you send up a second shuttle to help, and risk launch damage on that one as well?
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Nasa knew there were a 30inch by 14inch gash in the tiles on the left wing two days before re-entry.
Where did you get this information?
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Originally posted by davidpt40
Nasa knew there were a 30inch by 14inch gash in the tiles on the left wing two days before re-entry.
That's simply not true. Where are you getting your news from? I was watching one of the NASA news conferences just 2 days ago and they were showing pictures of the underside of the left wing during the launch. The pictures were taken before and after the debris hit the wing. There was no diference in the under side of the wing before or after. The guy did say that the resolution wasn't as good as they would like, but from what they could tell from those pictures there was no damage from the debris.
They've also been saying since day one that there have been tiles lost before. I even heard one of them say that they have had large pieces of tile gone during reentry and that structural damage (burning in reentry) has happened.
But NASA screwed up and got the entire space crew killed, for the THIRD time (apollo 1, challenger, and Columbia).
I hope nobody from NASA flies AH and sees this comment. If all of NASA haven't figured out what happened yet I doubt very seriously that any of us here have a clue. For all we know the flight control computer just messed up. Or the 21 year old airframe couldn't handle 28 or 29 reentries.
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That's simply not true. Where are you getting your news from?
MSN news. NASA circulated a memo 2 days before reentry about a 30x14inch gash in the wing. I assume the article meant to say gash in the tiles.
I hope nobody from NASA flies AH and sees this comment.
Why is that? The first crew death resulted from pumping the cabin of the Apollo 1 capsule full of pure oxygen. On top of that, the astronauts didn't even burn to death, they ashpixiated because of an overly complicated hatch that took 2 minutes to open under optimal conditions.
The second spacecraft destruction could have been avoided entirely. Engineers told NASA about the O-rings, I have seen the interviews. At least one of the shuttle engineers was extremely passionate about the dangers of frigid temperatures, and NASA still wouldn't listen to him.
The Columbia disentegration was the least preventable of all 3 disasters, but I do believe it was still preventable.
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Originally posted by davidpt40
Why is that? The first crew death resulted from pumping the cabin of the Apollo 1 capsule full of pure oxygen. On top of that, the astronauts didn't even burn to death, they ashpixiated because of an overly complicated hatch that took 2 minutes to open under optimal conditions.
They used oxygen because it is easier to control a simpler atmosphere, and they got away with it all thru Mercury and Gemini. Like the Zeppilin company and its use of hydrogen, NASA thought they tamed the monster.
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Originally posted by Holden McGroin
I think NASA is deemphasising the foam strike so that they can try to gather as much evidence and thouroughly examine as much as possible before theorizing.
Some of the problems of the tile repair scenario:
-lots of problems listed here-.
A British NASA scientist was on the radio here, saying that NASA had a heatshield tile repair kit on board the shuttle once, but due to budgetary constraints the kit, the training program and everything associated with it was cut from the Shuttle program some time ago
So they had a kit to make repairs (theoretically at least) but it got axed. I don't know if it was ever used however, and it would seem that it would not have made any difference to the fate of the Columbia.
He wasn't saying "budgetary constraints killed the Coumbia".
Anyone know if this (tile repair kit) did exist and was axed?
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Anyone know if this (tile repair kit) did exist and was axed?
I don't know, but in this case it wouldn't have mattered. I don't believe they had either the equipment or the training to spacewalk on this flight.
ra
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What I read somewhere was that none of the astronauts had the proper training for spacewalks, so that was out of the question.
There was really nothing they could do.
no fuel to get to ISS (no docking ring either)
no arm installed to examine possible damage
no one aboard who can go outside to check it out
so your options are basically zero