bhmit1 writes "It looks like NASA is reporting that no repairs are needed for Endeavor. 'After meeting for five hours, mission managers opted Thursday night against any risky spacewalk repairs, after receiving the results of one final thermal test. The massive amount of data indicated Endeavor would suffer no serious structural damage during next week's re-entry. Their worry was not that Endeavor might be destroyed and its seven astronauts killed in a replay of the Columbia disaster — the gouge is too small to be catastrophic. They were concerned that the heat of re-entry could weaken the shuttle's aluminum frame at the damaged spot and result in lengthy post-flight repairs.'"
Their worry was not that Endeavor might be destroyed and its seven astronauts killed in a replay of the Columbia disaster -- the gouge is too small to be catastrophic. They were concerned that the heat of re-entry could weaken the shuttle's aluminum frame at the damaged spot and result in lengthy post-flight repairs
And I'm sure thats the only thing the astronauts were worried about as well... the precious shuttle.
It reminds me of a while back when a friend of mine called his mother to tell her he had a few drinks and was gonna stay the night at a friend's house. Her response was, "Yeah, I wouldn't want anything to happen to the car."
Regardless, I admire their fortitude given the history of the Columbia and all that has happened. I hope everything goes well and they get home safely.
-- Captialism: When it uses the carrot, it's called democracy. When it uses the stick, it's called facism.
Here's where we get to watch a lot of folks decide whether to comment on the effects of something outside of their experience and expertise.
I've seen photos and 3D imaging of the bashed tiles. I know very little of the forces involved. I have seen no structural analysis of the materials that are beneath the deepest part of the gouge.
To a limited extent, I can compare this damage to the past damaged tiles. There seem to have been a number of similar damaged tiles in the past, and those flights landed safely.
The astronauts could slap some of that goop on the gouge, but risk damaging the tiles by accident, or changing the aerodynamics of the craft.
There are many unknowns. I really don't know what will happen when Endeavour reenters.
I wish them well, and hope that NASA can complete the remaining shuttle flights without mishap.
As a former USAF avionics specialist and later crew chief, one thing was always true:
The decision about air-worthiness, mission-worthiness was the pilot's, the aircraft commander.
It didn't matter if I told him that sure, the plane will fly, if he didn't like it, the plane didn't fly.
So, NASA, provide all the information to the commander, pilot, and crew, and let THEM make the call. If you don't like what they decide, it can be taken up AFTER the mission.
But that's the difference between an aircraft and a spacecraft -- an aircraft pilot can look his plane over, read up on the maintenance, talk to his ground crew and then decide to fly or not. In NASA, it works differently. A Space Shuttle commander has command of the spacecraft, but Mission Control in Houston has command of the mission. You have to remember: the crew of the Shuttle can't just go bombing around in Earth orbit like they are flying the Millennium Falcon. Every move has to be choreographed and planned out months and even years in advance. When unexpected problems crop up, the technicians on the ground certainly know more about the workings of the machine than the crew, as they have all the data at the fingertips, they are experts in their systems, and they can draw on contractor resources to get more information. Decisions like this cannot be left to the spacecraft commander; his/her job is hard enough without having to keep in their head the compendious amount of information regarding their spacecraft.
It has been this way since Mercury; it was Chris Kraft who outlined the need for the ground to have the skills required to manage the mission and deal with problems in real time, so that the crew could concentrate on their activities in space. The system has worked extremely well over all these years, with the exception of the Columbia accident. I for one am confident that NASA knows what it is doing and will take all the precautions it can before Endeavour is allowed to land.
Fly it home, unfixed is what Houston has ordered. Hopefully the man who made decision has signed his name to it.
The decision is by committee. The consensus to fly home was made last night and was unanimous among the committee. They did extensive analysis both with CFD, analytical models and arc jet testing.
They do have procedures, and materials. Since the last disaster, they have sent up patch kits. If its not adequate, they can send up one that is on the next go round. They chose not to patch because
And I'm sure thats the only thing the astronauts were worried about as well... the precious shuttle. If the only thing mission control was worried about was "the precious shuttle", then they would have just sent them out right away to fix the gouge.
Spacewalks are potentially dangerous. Micro-meteorites could tear right through a spacesuit and instantly kill an astronaut. They aren't taken lightly and are always judged whether the benefits justify the risks. In this case, they didn't.
Couldn't they just create some type of shield such as teflon or some other strong material to be placed a short distance from them covering their backs? I would assume that the spacecraft covers their front.
The faster meteoroids might be travelling at roughly 30-40 km/sec. (*) [anl.gov] In comparison, here on Earth the fastest bullets cruise at around 1.2 km/sec, with slower bullets loping about in the neighborhood of 0.3 to 0.6 km/sec. (*) [hypertextbook.com]
All the strong layers of whatever you want to strap onto an astronaut in addition to all the crap s/he's already got to wear and maneuver through won't help all that much against a small particle moving at that speed.
NASA haven't panicked and issued all kinds of worrying proclamations when it wasn't worried in the past: why start now?
Because they weren't all that worried about Columbia either. Seven astronauts died because of that.
Don't get me wrong, I see what you're saying. The damage may indeed be comparable to previous missions that went off without a hitch. And it is true, all of the lab tests show no cause for concern. But as another poster mentioned below, all the lab tests in the world can't make up for a real world scenario. The real world always has another trick up it's sleeve.
And you also need to realize that NASA needs to be extra cautious. A repeat of the Columbia disaster would raise some serious concerns about their credibility and may be detrimental to the future of space exploration in general.
-- Capitalism: When it uses the carrot, it's called democracy. When it uses the stick, it's called facism.
>>Because they weren't all that worried about Columbia either. Seven astronauts died because of that.
In all fairness, nobody at NASA knew the extent of the damage to Columbia prior to reentry. There were engineers who suspected that there might be some, and wanted photography to be sure, which NASA disallowed. If the existence of a large hole in the leading edge of the wing was known, some type of rescue operation could possibly have been put into place, as there was no repair possibility at that time.
In this case, NASA had detailed imagery of the damaged area several days before the return. That allowed for detailed analysis and laboratory testing, which have apparently convinced NASA that the extent of damage is limited enough that no repairs are required prior to reentry.
I would like to know what assumptions were used in making the "no repair" decision, nonetheless. It would seem to me that even if the damage was not severe enough to REQUIRE the repair, this situation provided a chance to test out the newly developed repair techniques and materials in a "real world" setting, allowing engineers and future crews to gain more confidence in the repairs if and when they are required on a future mission. Is the risk of an EVA/repair causing further damage really high enough to justify throwing away what could be a very valuable "learning experience"?
It is unlikely that a rescue would have been possible. It would've required extreme fast-tracking of one of the other shuttles, which NASA has proven to be unable to do. While I was living in FL, I think there was maybe one launch that went up at the original scheduled time, many were postponed, and the vast majority ended up postponed to over a week later. The disappointing thing about Columbia however, is that knowing no rescue or repair would be possible they decided additional imaging was unnecessary:
Actually, their primary concern was the EVA its self. The suits are showing possible signs of aging (a 2 inch tear in the top two layers of a glove on the last EVA). They don't want an astronaut to be at risk of decompression while attempting a repair that is not life threatening. -nB
"And you also need to realize that NASA needs to be extra cautious. A repeat of the Columbia disaster would raise some serious concerns about their credibility and may be detrimental to the future of space exploration in general." They don't care enough about space exploration to halt the use of old systems like the Shuttle, continue exploration with unmanned systems, then send meat into space with more mature technology. This isn't 1492, and we are under no pressure to send crews off in the modern equivalent
"(Good thing we didn't expect zero casualties in the era of test pilots, or aviation would not have gotten very far.)" What bothers me isn't that there are people taking risks to advance our knowledge. What bothers me is that they are taking risks to prevent advancing our knowledge.
It took more than 100 flights and the loss of a ship with its crew to make NASA start looking at what happens to a shuttle during launch.
It's one thing when people die because you couldn't foresee a problem in a new wing design or
IMHO if something happens during a space walk, You still can bring the astronaut back on board, and still can try an unrepaired re-entry. But even if the repairing astronaut dies (which is very unlikely), the others are still alive.
And what if the astronaut perched at the end of a 100-foot boom crashes into the tiles he's repairing, damaging them more extensively, or even beyond repair? After all, the arm is very heavy and the EVA suit is 300 pounds, along with the 200lb astronaut inside of it. That's a lot of mass to be swinging around next to all the other, undamaged tiles.
Or what if the 'goop', applied unevenly, causes a hot spot on another tile? Right now, the damaged tiles are located over a wing spar - the thickest structural part of the wing, and a section that can take more heating. Since the depth of the gouge indicates that the plasma flow over it will 'eddy' over the deepest area, keeping it from the greatest heat of reentry, models indicate that the aluminum structure of the shuttle won't fail, and that temperatures won't exceed 350f.
The problem with speculating on NASA decisions, as so many coffee urn quarterbacks are doing this morning, is that they really have no idea how complex the shuttle and its mission really are. The items I've outlined here, available in almost no major news stories about the decision, were easily obtained at NASA Tv and Aviation week - and they're a small sample of the factors in this decision.
It's unfortunate, this could have been a good test case to see how the repair materials/procedures work under realistic conditions.
Having firm, experimental data about:
* The process of applying the patch * How well the patch stands up to re-entry * How well the patch protects underlying systems
and more. Better to get this data on a 'non-critical' bit of damage than waiting until something is REALLY busted before finding the inadequecy.
They've done extensive testing on the ground, I'm sure, but a real-world test scenario can trump ten lab extrapolations. That's why we do external betas of software, the real world always has something up it's sleeve.
There's much safer ways to do tests like that in space. It would be trivial to create a small section of tiles attached to one of the robot arms and pre-gouge it. Astronauts could practice working on it. Why NASA hasn't done that, I don't know. I do think it'd be a good idea to have some sort of real-world test for these repairs.
The Astronauts -have- practiced patching tiles in the cargo bay. But those tiles can't be on the outside of the shuttle during reentry.
While I was writing my previous response I thought about the idea of 'pre-patching' some tiles near the rear of the shuttle before launch, in order to see how well those tiles did on reentry. Can you imagine the outcry if NASA suggested purposely -damaging- a few 'unimportant tiles' before the mission even begins? And I doubt you can easily add a few spare tiles to the a
Also, launching the shuttle with "pre-patched" tiles would mean that NASA still wouldn't have any data on the feasibility of applying the repair materials during the flight. Working in the cargo bay is one thing, but trying to repair tiles on the belly while attached to the end of the robotic arm is yet another.
The tiles are extremely delicate. NASA viewed a lumbering astronaut in a suit ill designed for delicate work, with a tube of superglue and a squeege in the area around the main heat shield of the Shuttle a far greater threat then the small hole.
What's that mantra we IT folks keep repeating?... If it ain't broke, don't fix it.
I'd argue it's better to wait until the shuttle's really busted before trying out complex repair maneuvers. In that case, the shuttle's already a writeoff; if the astronaut crashes into the tiles or they're otherwise damaged, it won't matter.
Now that link is a bit of a read, but a very striking introduction on influencing decision-making with presentation techniques, even if this costs other people's lives.
...or the shuttle's days will be numbered even if it is still a useful tool.
Endeavour is currently on the sixth shuttle mission since Columbia was lost. On Slashdot there's a chance that somebody could tell you what was achieved on any of those six missions. Ask an average member of the public though, and I guarantee you that less than 1% have any idea of a single piece of scientific research achieved on any of those six flights.
A large number of those members of the public will be able to tell you
Who cared about the space program after Apollo 11 other than nerds?
Spirit and Opportunity have entered year three, well past their 90 day expected life span, yet I'd wager the lost Polar Lander and crashed Climate Orbiter got more press than the little rovers that could ever will.
...why don't they replace the tiles anyway, just to be sure? The article suggests that a spacewalk would create added risk, but we know that spacewalks occur all the time routinely. Perhaps there is a financial motivation for not carrying out the repair? I don't know.
What I'd like to see is an actual breakdown of the possible positive and negative consequences of each course of action and the probabilities that NASA has assigned to the outcomes. I'm really hoping that they've put some serious statisti
They can't replace the tiles - the tiles are fitted to the shape of the Shuttle; every tile is different.
They have a patch kit, but in applying the patch they could weaken the tiles that they're patching. So it's a tradeoff. If they perform the repair and all goes well, then they're probably better off than before. But if something goes wrong during the repair, things could get a lot worse.
It would be problematic to replace the affected tiles.....if I remember from old articles (don't have links, sorry), each tile is unique and not the same size as its neighbor (although they visually appear to be). You would have to grind it or somehow alter the shape to make it fit the hole precisely as it should.
If they used the caulk, I would worry about the goop bubbling out or not being flush with the surrounding surface, thereby creating drag which may pull the whole tile out, which would leave a
I read Osheroff's quote and decided he's talking out his ass (or it's a lousy quote). Perhaps successful repairs can only increase their chances, but things can and do go wrong, and it wasn't explained how Osheroff was in a better position to make the analysis than the people at NASA doing it. BTW, if you read the article carefully, it seems that financial considerations would lean toward doing the repair, not avoiding it. Leaving the gouge in place may result in more down-time and repair work for Endeav
They can't actually replace entire tiles on orbit. They have a 'patching' system which allows them to spread a compound into any nicks in the tiles.
Now, the compound has to be applied by an astronaut attached to a long extension arm attached to the Shuttle's robotic arm. When they tested this a few flights ago, it became readily apparent that it was at best difficult to work this way. The length of the arm caused significant 'bouncing' with every motion. At the time they only pulled a gap filler and simulated the motion of filling a tile and it wasn't easy.
The real danger is that the control issues of having a 'massive' astronaut + EVA gear swinging around on the end of that very long arm so close to the TPS could actually cause more damage to the tiles than it fixed.
Furthermore, the compound could actually cause even worse localised heating issues on re-entry depending on how well it fills the tile ie: It could cause ducting etc.
but we know that spacewalks occur all the time routinely.
What's risky about this isn't the space walk itself but the concept of damaging more tiles. It's a delicate operation and one slip can make things go from bad to worse easily.
Perhaps there is a financial motivation for not carrying out the repair?
What financial motivation? The material already exist onboard. There is no investment and the amounts by which NASA would be set back in the case of a mid-air breakup or even a safe landing with an unus
The HRSI tiles are made of a low-density, high-purity silica 99.8-percent amorphous fiber (fibers derived from common sand, 1 to 2 mils thick) insulation that is made rigid by ceramic bonding. Because 90 percent of the tile is void and the remaining 10 percent is material, the tile weighs approximately 9 pounds per cubic foot.
Actually, they are quite delicate. I know, because I've got a piece of the material. And no, I'm no one special... they sell it (or used to) in the KSC gift shop. A tap won't "snap" it but it will crush that spot... these things are like a silica sponge, mostly air. Great insulators, at the expense of being extremely fragile. It can't take much of a bump without damage.
I managed to easily put some marks into my sample before I smartened up and kept it in its case.
Angry General: Son, what do you mean you've blown my multi-billion dollar shuttle ?
Pissing-in-his-pants Soldier: Well, there was this small gouge you see, we had experts analyze it and they said it was not urgent.
Angry General: you mean you wouldn't spend a few tens of thousand bucks to keep a multi-billion shuttle in good health ? I'll tell you what, why don't you and your experts go clean the toilets with your tongue while you think things through...
I'm under the impression they've had dozens of defects more extensive than this one in the hundre-plus returns. At least they did laboratory tests and computer modeling of the exact defect they discovered this time.
....NASA's in-space repair abilities that they spent gobs of money on after Columbia remind me a lot about our "Disaster Recovery" plans at my firm. Sure.. we have one; Sure.. we spend a lot of money on it;... but please.. oh please.. don't make us actually test it or put it into practice.
I hope they didn't just spend all that money so that could check the "Disaster Recovery" check box on some form and quiet the complaints.
They've already determined that the gouge will not endanger the astronauts lives if left alone. The question they just answered was do they risk more damage to the heat shield by attempting a repair in space or not. It sounds like they'd rather be safe and leave it alone and spend more money on repairs on the ground than risk killing the astronauts.
I take it you're the type that pushes out service packs day one throughout a corporate network too. What if the astronaut crashes into the tiles? What if the arm locks up? What if the repairs cause more damage to the tiles? NASA's a very conservative organization. They already take risks that'd make most people white, they're not keen to take on more than they have to.
If a shuttle gets damaged to the point where repairs are required, it won't matter if the situation is made worse because it's already des
The problem with that is that the lives of the crew are riding on the potential repair. Without knowing the effect in advance, the risk in making the repair is increased, beyond the risk the crew undergoes in suiting up and spacewalking in the first place. Remember, they have already had a partial glove failure. The repair itself is not without considerable risk. They have had similar gouges before and the Shuttle has landed perfectly fine. Now is not the time to experiment. They can certainly perform exper
We seem to have forgotten that in the U.S. lately. Granted, the integrity of the shuttle frame is not worth human life, but the panicked semi-troll responses to this crisis made me realize yet again how far we've fallen as a society.
The same people are "concerned" now, as the ones who were calling for ending the space program after Columbia.
We are so fat and content that we seem to think that anything that interferes with our blissful lives must be a curse. We have forgotten the drive and determination of scientists, engineers, and many others, which made the world we're living in possible. Make no mistake about it - without self-sacrifice, many of the technological and scientific developments that shaped the latter half of the 20th century would not have been possible.
Yet the population, spurred on by the scaremongering media, seem to think that we've now magically gotten to a point at which we can make everything safe. Well... we almost can... if we all just stay home. But if we want another revolution in the development of our species, like the one that spanned 1850-1975, we will have to accept that some things are worth it. Yes, it's important to minimize risk... but sometimes you have to accept a reasonable amount of risk, take a deep breath, and just go.
If they are that concerned with cutting costs than saving life's, they should stop sending people in to space.
Actually, the whole point is that they weren't.
The problem is that so far in a relatively short interval they had two cuts in two spacesuits' gloves during spacewalks. The last one was a two inch gash, and prompted an immediate abort of the spacewalk. Precisely because noone wants to vaccuum an astronaut.
Now they weren't all the way through the glove. At least the latest one had only cut the top two
Well it's not offensive when you put it like that, but it's still not right. They are still considering the lives the astronauts at the expense of the shuttle. Their analysis and simulation said that with the present damage the worst that will happen is that the shuttle's wing might be damaged and require lengthy, expensive repairs on the ground. That's the money angle. They could try to patch the damage and prevent this, but EVA is dangerous and these repairs are difficult, if it ends up causing more damage to the delicate tiles then all the astronauts' lives are in danger. On-the ground repairs, no matter how expensive, are a better option.
The feather reentry technique is only useful at suborbital speeds. How do you expect the spacecraft to slow down to these speeds? The only option is to use the underside of the shuttle as a heat shield as it is barreling through our atmosphere. What other options are there? You can't use a fuel burn because that would enormously increase the launch weight, and therefore the cost, of every mission. The shuttle was designed by some of the best aerospace engineers in the world. I'm sure every crazy reentry opt
I'm glad I don't have to make these calls (Score:5, Insightful)
It reminds me of a while back when a friend of mine called his mother to tell her he had a few drinks and was gonna stay the night at a friend's house. Her response was, "Yeah, I wouldn't want anything to happen to the car."
Regardless, I admire their fortitude given the history of the Columbia and all that has happened. I hope everything goes well and they get home safely.
--
Captialism: When it uses the carrot, it's called democracy. When it uses the stick, it's called facism.
IANAAE (Score:4, Insightful)
I've seen photos and 3D imaging of the bashed tiles. I know very little of the forces involved. I have seen no structural analysis of the materials that are beneath the deepest part of the gouge.
To a limited extent, I can compare this damage to the past damaged tiles. There seem to have been a number of similar damaged tiles in the past, and those flights landed safely.
The astronauts could slap some of that goop on the gouge, but risk damaging the tiles by accident, or changing the aerodynamics of the craft.
There are many unknowns. I really don't know what will happen when Endeavour reenters.
I wish them well, and hope that NASA can complete the remaining shuttle flights without mishap.
Parent
Hey, NASA, here's an idea... (Score:5, Interesting)
As a former USAF avionics specialist and later crew chief, one thing was always true:
The decision about air-worthiness, mission-worthiness was the pilot's, the aircraft commander.
It didn't matter if I told him that sure, the plane will fly, if he didn't like it, the plane didn't fly.
So, NASA, provide all the information to the commander, pilot, and crew, and let THEM make the call. If you don't like what they decide, it can be taken up AFTER the mission.
Parent
Re:Hey, NASA, here's an idea... (Score:5, Informative)
But that's the difference between an aircraft and a spacecraft -- an aircraft pilot can look his plane over, read up on the maintenance, talk to his ground crew and then decide to fly or not. In NASA, it works differently. A Space Shuttle commander has command of the spacecraft, but Mission Control in Houston has command of the mission. You have to remember: the crew of the Shuttle can't just go bombing around in Earth orbit like they are flying the Millennium Falcon. Every move has to be choreographed and planned out months and even years in advance. When unexpected problems crop up, the technicians on the ground certainly know more about the workings of the machine than the crew, as they have all the data at the fingertips, they are experts in their systems, and they can draw on contractor resources to get more information. Decisions like this cannot be left to the spacecraft commander; his/her job is hard enough without having to keep in their head the compendious amount of information regarding their spacecraft.
It has been this way since Mercury; it was Chris Kraft who outlined the need for the ground to have the skills required to manage the mission and deal with problems in real time, so that the crew could concentrate on their activities in space. The system has worked extremely well over all these years, with the exception of the Columbia accident. I for one am confident that NASA knows what it is doing and will take all the precautions it can before Endeavour is allowed to land.
Parent
Re: (Score:3, Interesting)
The decision is by committee. The consensus to fly home was made last night and was unanimous among the committee. They did extensive analysis both with CFD, analytical models and arc jet testing.
They do have procedures, and materials. Since the last disaster, they have sent up patch kits. If its not adequate, they can send up one that is on the next go round. They chose not to patch because
Memo to all NASA employees: (Score:4, Funny)
However tempting it may be, given the considerable savings, please don't source any more tiles from "Home Depot".
NASA Mgmt.
Parent
Re:I'm glad I don't have to make these calls (Score:5, Insightful)
If the only thing mission control was worried about was "the precious shuttle", then they would have just sent them out right away to fix the gouge.
Spacewalks are potentially dangerous. Micro-meteorites could tear right through a spacesuit and instantly kill an astronaut. They aren't taken lightly and are always judged whether the benefits justify the risks. In this case, they didn't.
Parent
Meteroid speed (Score:3, Interesting)
Couldn't they just create some type of shield such as teflon or some other strong material to be placed a short distance from them covering their backs? I would assume that the spacecraft covers their front.
The faster meteoroids might be travelling at roughly 30-40 km/sec. (*) [anl.gov] In comparison, here on Earth the fastest bullets cruise at around 1.2 km/sec, with slower bullets loping about in the neighborhood of 0.3 to 0.6 km/sec. (*) [hypertextbook.com]
All the strong layers of whatever you want to strap onto an astronaut in addition to all the crap s/he's already got to wear and maneuver through won't help all that much against a small particle moving at that speed.
Re:I'm glad I don't have to make these calls (Score:5, Insightful)
Don't get me wrong, I see what you're saying. The damage may indeed be comparable to previous missions that went off without a hitch. And it is true, all of the lab tests show no cause for concern. But as another poster mentioned below, all the lab tests in the world can't make up for a real world scenario. The real world always has another trick up it's sleeve.
And you also need to realize that NASA needs to be extra cautious. A repeat of the Columbia disaster would raise some serious concerns about their credibility and may be detrimental to the future of space exploration in general.
--
Capitalism: When it uses the carrot, it's called democracy. When it uses the stick, it's called facism.
Parent
Re:I'm glad I don't have to make these calls (Score:5, Insightful)
In all fairness, nobody at NASA knew the extent of the damage to Columbia prior to reentry. There were engineers who suspected that there might be some, and wanted photography to be sure, which NASA disallowed. If the existence of a large hole in the leading edge of the wing was known, some type of rescue operation could possibly have been put into place, as there was no repair possibility at that time.
In this case, NASA had detailed imagery of the damaged area several days before the return. That allowed for detailed analysis and laboratory testing, which have apparently convinced NASA that the extent of damage is limited enough that no repairs are required prior to reentry.
I would like to know what assumptions were used in making the "no repair" decision, nonetheless. It would seem to me that even if the damage was not severe enough to REQUIRE the repair, this situation provided a chance to test out the newly developed repair techniques and materials in a "real world" setting, allowing engineers and future crews to gain more confidence in the repairs if and when they are required on a future mission. Is the risk of an EVA/repair causing further damage really high enough to justify throwing away what could be a very valuable "learning experience"?
Parent
Re: (Score:3, Insightful)
The disappointing thing about Columbia however, is that knowing no rescue or repair would be possible they decided additional imaging was unnecessary:
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-nB
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They don't care enough about space exploration to halt the use of old systems like the Shuttle, continue exploration with unmanned systems, then send meat into space with more mature technology.
This isn't 1492, and we are under no pressure to send crews off in the modern equivalent
Re: (Score:3, Interesting)
What bothers me isn't that there are people taking risks to advance our knowledge. What bothers me is that they are taking risks to prevent advancing our knowledge.
It took more than 100 flights and the loss of a ship with its crew to make NASA start looking at what happens to a shuttle during launch.
It's one thing when people die because you couldn't foresee a problem in a new wing design or
Re:I'm glad I don't have to make these calls (Score:5, Informative)
Or what if the 'goop', applied unevenly, causes a hot spot on another tile? Right now, the damaged tiles are located over a wing spar - the thickest structural part of the wing, and a section that can take more heating. Since the depth of the gouge indicates that the plasma flow over it will 'eddy' over the deepest area, keeping it from the greatest heat of reentry, models indicate that the aluminum structure of the shuttle won't fail, and that temperatures won't exceed 350f.
The problem with speculating on NASA decisions, as so many coffee urn quarterbacks are doing this morning, is that they really have no idea how complex the shuttle and its mission really are. The items I've outlined here, available in almost no major news stories about the decision, were easily obtained at NASA Tv and Aviation week - and they're a small sample of the factors in this decision.
Parent
A chance for testing lost (Score:4, Interesting)
Having firm, experimental data about:
* The process of applying the patch
* How well the patch stands up to re-entry
* How well the patch protects underlying systems
and more. Better to get this data on a 'non-critical' bit of damage than waiting until something is REALLY busted before finding the inadequecy.
They've done extensive testing on the ground, I'm sure, but a real-world test scenario can trump ten lab extrapolations. That's why we do external betas of software, the real world always has something up it's sleeve.
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Re: (Score:2, Interesting)
While I was writing my previous response I thought about the idea of 'pre-patching' some tiles near the rear of the shuttle before launch, in order to see how well those tiles did on reentry. Can you imagine the outcry if NASA suggested purposely -damaging- a few 'unimportant tiles' before the mission even begins? And I doubt you can easily add a few spare tiles to the a
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I'd argue it's better to wait until the shuttle's really busted before trying out complex repair maneuvers. In that case, the shuttle's already a writeoff; if the astronaut crashes into the tiles or they're otherwise damaged, it won't matter.
infamous powerpoint presentation (Score:3, Interesting)
Now that link is a bit of a read, but a very striking introduction on influencing decision-making with presentation techniques, even if this costs other people's lives.
NASA needs to get out of the media black hole (Score:2, Interesting)
Endeavour is currently on the sixth shuttle mission since Columbia was lost. On Slashdot there's a chance that somebody could tell you what was achieved on any of those six missions. Ask an average member of the public though, and I guarantee you that less than 1% have any idea of a single piece of scientific research achieved on any of those six flights.
A large number of those members of the public will be able to tell you
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Spirit and Opportunity have entered year three, well past their 90 day expected life span, yet I'd wager the lost Polar Lander and crashed Climate Orbiter got more press than the little rovers that could ever will.
If I were one of the shuttle astronauts (Score:2)
One final test (Score:5, Funny)
While playing Stairway to Heaven, bic lighters were waved back and forth over the affected area.
To err on the side of caution... (Score:2, Insightful)
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They have a patch kit, but in applying the patch they could weaken the tiles that they're patching. So it's a tradeoff. If they perform the repair and all goes well, then they're probably better off than before. But if something goes wrong during the repair, things could get a lot worse.
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If they used the caulk, I would worry about the goop bubbling out or not being flush with the surrounding surface, thereby creating drag which may pull the whole tile out, which would leave a
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If it aint [all that] broke, don't fix it. (Score:4, Informative)
Now, the compound has to be applied by an astronaut attached to a long extension arm attached to the Shuttle's robotic arm. When they tested this a few flights ago, it became readily apparent that it was at best difficult to work this way. The length of the arm caused significant 'bouncing' with every motion. At the time they only pulled a gap filler and simulated the motion of filling a tile and it wasn't easy.
The real danger is that the control issues of having a 'massive' astronaut + EVA gear swinging around on the end of that very long arm so close to the TPS could actually cause more damage to the tiles than it fixed.
Furthermore, the compound could actually cause even worse localised heating issues on re-entry depending on how well it fills the tile ie: It could cause ducting etc.
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What's risky about this isn't the space walk itself but the concept of damaging more tiles. It's a delicate operation and one slip can make things go from bad to worse easily.
Perhaps there is a financial motivation for not carrying out the repair?
What financial motivation? The material already exist onboard. There is no investment and the amounts by which NASA would be set back in the case of a mid-air breakup or even a safe landing with an unus
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http://science.ksc.nasa.gov/shuttle/technology/sts -newsref/sts_sys.html [nasa.gov]
My structural physics knowledge is a bit lacking, but something made of 10% rigid fibre 1-2mm thick and 90% void
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I managed to easily put some marks into my sample before I smartened up and kept it in its case.
Not even Duct tape?! (Score:4, Funny)
Angry General (Score:2)
Son, what do you mean you've blown my multi-billion dollar shuttle ?
Pissing-in-his-pants Soldier:
Well, there was this small gouge you see, we had experts analyze it and they said it was not urgent.
Angry General:
you mean you wouldn't spend a few tens of thousand bucks to keep a multi-billion shuttle in good health ? I'll tell you what, why don't you and your experts go clean the toilets with your tongue while you think things through...
A bit of Tile prediction History: all bad (Score:2, Informative)
how many tile defects in past? (Score:2)
Nasa Repair Plan reminds me of.... (Score:2)
I hope they didn't just spend all that money so that could check the "Disaster Recovery" check box on some form and quiet the complaints.
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What if the astronaut crashes into the tiles? What if the arm locks up? What if the repairs cause more damage to the tiles? NASA's a very conservative organization. They already take risks that'd make most people white, they're not keen to take on more than they have to.
If a shuttle gets damaged to the point where repairs are required, it won't matter if the situation is made worse because it's already des
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The problem with that is that the lives of the crew are riding on the potential repair. Without knowing the effect in advance, the risk in making the repair is increased, beyond the risk the crew undergoes in suiting up and spacewalking in the first place. Remember, they have already had a partial glove failure. The repair itself is not without considerable risk. They have had similar gouges before and the Shuttle has landed perfectly fine. Now is not the time to experiment. They can certainly perform exper
Re:Disaster waiting to happen (Score:5, Insightful)
We seem to have forgotten that in the U.S. lately. Granted, the integrity of the shuttle frame is not worth human life, but the panicked semi-troll responses to this crisis made me realize yet again how far we've fallen as a society.
The same people are "concerned" now, as the ones who were calling for ending the space program after Columbia.
We are so fat and content that we seem to think that anything that interferes with our blissful lives must be a curse. We have forgotten the drive and determination of scientists, engineers, and many others, which made the world we're living in possible. Make no mistake about it - without self-sacrifice, many of the technological and scientific developments that shaped the latter half of the 20th century would not have been possible.
Yet the population, spurred on by the scaremongering media, seem to think that we've now magically gotten to a point at which we can make everything safe. Well... we almost can... if we all just stay home. But if we want another revolution in the development of our species, like the one that spanned 1850-1975, we will have to accept that some things are worth it. Yes, it's important to minimize risk... but sometimes you have to accept a reasonable amount of risk, take a deep breath, and just go.
Anyway, sorry about the rant...
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They weren't (Score:2)
Actually, the whole point is that they weren't.
The problem is that so far in a relatively short interval they had two cuts in two spacesuits' gloves during spacewalks. The last one was a two inch gash, and prompted an immediate abort of the spacewalk. Precisely because noone wants to vaccuum an astronaut.
Now they weren't all the way through the glove. At least the latest one had only cut the top two
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Re:Disaster waiting to happen (Score:4, Insightful)
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-->I share that exact memory. And the teachers trying hard to figure out how to explain all that to the students.
Aside from finding out that Vader was Luke's Father, that may have been the biggest WTF! moment of childhood.
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