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Shuttles Grounded Once Again
PipianJ writes "After discovering that the piece of the shuttle that fell off mysteriously, not actually striking it, (as reported earlier) was a piece of foam insulation not unlike the piece that ended up in the destruction of Columbia, Yahoo News reports that NASA has once again grounded the shuttle fleet."
...to wake up to, if you're on the Shuttle in orbit! That has just GOT to be a major morale booster for the people currently in space.
"Uh, yeah. Remember Columbia? Well, to make sure it doesn't happen again, none of the Shuttles are going to fly. Oh, except you guys. You're cool. Trust us."
Learning HOW to think is more important than learning WHAT to think.
This sounds like the death of US space travel, but maybe this will speed along a space shuttle replacement.
My days of not taking you seriously are certainly coming to a middle...
What do you suppose Burt Rutan could have done with that kind of funding? This is a disgrace.
Maybe they should start painting the foam again, as called for in the initial design spec. I know if was heavy and expensive, but it might stick together better.
Dude, I think I can see my house from here.
Comes at an expensive cost; paint has weight, and when you're coating that much surface area, the weight adds up. More weight on the tank, less the shuttle can lift as currently formatted.
No, the real thing we need to do is replace the fleet, and go through with the current redesign plans to place the shuttle's body utop the fuel tank. That way anything that falls hits an SRB and not the shuttle's hull.
Personally I think it pedantic and panicky to ground the whole fleet due to some insulation falling, but it was that which harmed Columbia. I mean every launch has had parts fall.
But, I guess I will side with them for now, until we get more information these next few days.
"Victory means exit strategy, and it's important for the President to explain to us what the exit strategy is." G.W.Bush
I wonder how risky was the cross atlantic sailing were in the mid 1500's. I am sure mortality was a lot higher then 1% then it is with the shuttle program. If you are going to ground the fleet when a takeoff was near perfect and inspection did not show any problems, but there was a bit of derby that the experts expected anyways, just seems like the politicians are in control and have no courage, because there are a few winers about it (Which would consist of probably the same percentage of people that the morality rate of the shuttle). Yes compared to Airplain, Boats of this era, and even cars, The shuttle is dangerous, that is why highly skilled pilots are on board, because it is dangerous.
If something is so important that you feel the need to post it on the internet... It probably isn't that important.
"Moore's law works on the shuttle too. if only NASA, and the government goons, would open the development and research funding to the public market."
No it doesn't. Aerodynamics is a pretty mature science. Look at cars, aircraft, and ships. They do not double in performance every 18 months.
1 Moore's law IS NOT law of physics like the speed of light is a constant.
2. Moore's law is based on observation of one specific technology integrated circuits.
3. Moore's law even for integrated circuits will have a limit.
The only way to improve the design drastically would be to build NEW shuttles. There is a limit to how much you can improve a design without building a new design.
See my blog http://ilovecookes.blogspot.com/ for light hearted technical information.
Not true.
Certain computing systems absolutely must operate reliably. Unfortunately, modern engineering does not offer a solution to the problem due to a number of constraints.
Essentially, teams setting out to write flawless systems will be practically incapable of doing so in reasonably complex instances.
Because of this, we use redundancy. It is of note, however, that people have been killed by buggy software, and that this is something that we can control with proper practices (by which I don't mean any of the more asinine things that the industry has come up with).
Instances of software both behaving well, and killing people because of malfunctions, can be found in domains such as health care and the military.
So a piece of foam that was like the one that hit Columbia fell off - the key difference being, that this one DIDN'T hit the shuttle.
On one hand, I can understand NASA's safety concerns - but, at the same time, it seems that they didn't do a lot to change the external fuel tank - its construction, etc. In fact, you could even say that this is why the shuttle was grounded from a July 13 launch - the sensor that was faulty was built in 1989.... they considered it to be in 'good condition', but, I mean, if it's a 16 year old piece of equipment, how good of condition is that? (I'm not exactly sure how this could be true - external tanks aren't reused, and so unless NASA stockpiled them in the late 80's, the tank would be newer; did the article just mean that it was a 1989 design?)
On the other hand - we know that pieces of foam have fallen off twice in the past 2 launches - once with devastating effects, and once without. I don't know if anyone at NASA saw fit to review old launch tapes and look for falling insulation à la the stuff that struck Columbia, but it seems possible that, given the construction of the external tank, it might be relatively common - and thus, nothing THAT BIG to worry about since its only been a problem 1/115 times. (Its still an inherent design flaw).
So, now the shuttle fleet is grounded again - will it be another 2 1/2 years? Making it early 2008 before the shuttle flies again? I mean, if it seems like foam just flies off of external tanks, the only way to REALLY solve this problem would be either encasing existing tanks in a new (heavy, expensive) "exo-tank," or just designing new tanks, right? I mean, this isn't some minor design consideration.
All this makes me think... with NASA already pressing for a new manned vehicle by 2010, are the powers that be in NASA just saying, "We don't want to fly the shuttle anymore, its a $2bn death trap, doesn't get us cool places and is damned inefficient at lifting cargo" and asking instead to concentrate on a new vehicle, just forgetting about the shuttle? I mean, if NASA spends $500m and 30 months modifying the shuttle fleet just to retire it 24 months after that, that seems dumb, right? Even by government standards?
Anyone?
Tim
If they had continued with development of the X-33 instead of turning it over to the Air Force and canceling the NASA development work, we would probably have a replacement by now. Instead, it will take probably a decade and substantially more money to bring a replacement vehicle to fruition from this point.
I suspect that politically, the manned space program is dead here in the US, given the huge budget deficits and slipping technology base.
There is the possibility that a superior insulating technology will be arrived at quickly and the remaining few shuttles might fly again, but I wouldn't bet on it. There is too much to be gained politically by stabbing the wounded for that to be allowed to happen.
Since the reason for the foam insulation on the tank is to prevent condensation from forming on the ground between the time the tank is filled with liquid fuel, and the time of launch, and is not needed past T-0, how about this?:
Jettison the foam at T-0, during engine ignition.
Velocity at that point in time is low enough that no foam strikes will have any chance of damaging orbiter tiles.
The foam and ice stay on the ground. The orbiter, and tank, go up. Probably a few thousand pounds lighter, as well.
Sure, there's the problem of getting all of the foam off in a few seconds, leaving none behind. Maybe by forming the foam around a fine, mesh netting, and attaching that netting to the ground via cables, it all slips right off at T-0.
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
That wouldn't be a very good idea...if the repair isn't absolutely necessary, you could risk doing further damage, considering the repair operation would be a new operation. For damage that they're fairly sure won't be fatal, they're much better off just leaving it alone.
I'd rather have a rocket with the payload where it's supposed to be: on top. Saturn V never worried about ice shedding, it was expected and not a problem because the payload was on top. Side mounted payloads are suicide.
I'm not religous, but godspeed Discovery.
gigantino.tv - Heavy but weighs nothing.
Actually, this particular chunck of foam IS relevant and an important event. Yes, lots of debris strikes the shuttles on lift-off, but most are quite small, much less than 1 lb or the "size of a suitcase" like the chunk that doomed Columbia. This piece they are concerned about was a similar size, but missed the orbiter. A strike from a similar sized piece of foam is a serious deal, unlike the 1" deep or less gouges to the tiles that are common. 1+ lb foam strikes will cause damage that is beyond the ability of NASA's still experimental repair methods.
So the big deal is not that some random foam bits came off, it's that a very large foam bit came off above the shuttle of comparable size to the one that popped a (non-repairable) hole in Columbia. This wasn't supposed to happen again.
A more sure-fire fix than better quality control would be to place a single layer of fiberglass/kevlar/(or maybe carbon) composite over the troublesome areas of the tank. Use a room-temp cure system and a layer a few thousandths thick. We use a woven "B" cloth at work that would do the trick. Yes, it'd add weight, but would solve the foam problem by adding some structure to work as a net to keep dislodged foam pieces with the tank and not flying towards the shuttle.
Then launch the few remaining shuttles to get thier work done and can the whole program.
Bryan Baskin
Dont know about you guys but a 1 in 113 chance of a massive catastrophy sounds pretty high to me.
And that's why they pay astronauts the big bucks.
The fact is space travel is still in its infancy. The space shuttle was supposed to transition us to the point where space travel was routine, but for a variety of reasons that never happened. We thought it was happening, in the early 1980's, but then the Challenger brought us back to reality (I actually wrote "back down to earth" before realizing what a bad metaphor that would be). Anyway, even if the shuttle was as successful at everything it was supposed to be, a transition is still a transition. The shuttle was to help us learn how to make space travel routine.
It's done that, but it is a complicated machine, and as the saying goes, this is rocket science. It's not easy, and I remember reading a bit after the Columbia accident that despite the OV (Orbiter Vehicle) designation the shuttles carry, they are still considered experimental vehicles within NASA and are treated as such. Astronauts are by definition test pilots. The fact that they actually get real work done on most missions is pretty amazing, considering. But they go into it with an understanding that it is dangerous work - even knowing that, could you imagine a better, more honorable way to die if it came to that? Would you rather die working for your country, for humanity, doing important scientific work that will pave the way for future generations, or would you rather die of a heart attack while sitting on a toilet taking a crap one day? This is the thinking astronauts have.
Someday, we will reach the point where space travel is relatively safe. But the early shuttle days were a red herring - space travel has never been safe, and it is still not safe. This doesn't mean we shouldn't do it. Since Columbia, there has been a rumbling that suggests if you can't make space flight as safe as atmospheric flight, that manned space flight should simply be abandoned until it can be. That's at least partly what's behind the decision to ground the fleet today - after all, nothing happened on Discovery's launch that hasn't happened on every other launch before. The issue is this is no longer considered an acceptable risk.
Maybe in the end this will be a good thing, and it will drive NASA to create more robust vehicles that genuinely are safer, and that will put us on a path towards commoditizing space travel. My fear is that it will simply scare us away from manned space travel altogether, which will be a shame.
The space shuttle fleet is definitely near the end of its useful life, though... which is kind of hard for me to acknowledge, as someone who watched the first experimental flights of the Enterprise live on TV in the 1970's. This was a huge event back then, filled with the promise of things to come. Well, like a lot of things in life, the shuttle program accomplished a whole lot of things but never quite did live up to its full potential. And now it's winding down, in a not very good way. Oh well, such is life, and hopefully NASA and the world will learn from the experience. I just really hope the recent shuttle problems don't scare this country away from space flight altogether. It is dangerous and we must accept that, even as we strive to make it safer.
Part of the problem here is that space exploration is inherently dangerous and risky. There is no way you will ever remove all of the risk -- and because of this there will be future accidents and loss of life while we explore the stars. The men and women who volunteer to do this are extremely courageous individuals that should be honored and thanked many times over. Each time a shuttle goes up, there are a million ways something can go wrong yet only one way everything can go perfectly. NASA, along with the government and general public, must understand that although the risks associated with space flight are huge, the potential rewards are far greater. Hopefully our government will give NASA the funding needed to develop a better way to put people in orbit. Until that time, we must realize that there are risks associated with each launch but we must keep aiming for the stars because, in the long run, humanity stands to gain far more than the risks from occasional loss of life that occur when something goes horribly wrong.
You honestly expect the US government, and/or NASA to admit something they have spent billions of tax-payers dollars on (and lined thousands of politicians pockets in the process) is a lost cause!? No way baby, the US is gonna milk this tit for everything it's worth. There will be more "accidents". I wonder how long it'll take the Bush Administration to slap a "terrorists" sticker on this if Discovery gets baked? I guess that's what you get for letting a 25 year old space craft be serviced and maintained by the lowest bidder.
I wonder how risky was the cross atlantic sailing were in the mid 1500's. I am sure mortality was a lot higher then 1% then it is with the shuttle program.
Although life was worth less then, at least there was an immediate economic incentive to making such a risky voyage. You could even frame it in terms of thousands of colonists that depend on those ships for trade. The only reason to send people into space currently is to send people into space. I personally think that's a decent reason, but I for my money's worth I'd rather put up a few new space telescope to find nearby planetary systems with or whatever, or send off a few robots to explore Mars or the moons of the gas giants.
The other problem with your argument is that no matter which century you live in, if given the choice between two transportation systems, all other things being about equal you should go with the more reliable one. Russia has a safer system, we should use it until we've built something comparable of our own.
A poor design is a poor design. It been pointed out by many /.ers that a cargo vessel should optimize for payload capacity, a passenger vessel should optimize for safety. A vessel that is both optimize (reads compromise) for passenger and payload is neither safe nor economical in terms $ / kg.
You say that foam shedding is "expected", and yet that misses the entire point of the post-Columbia investigation results. (And post-Challenger) for that matter.
Foam shedding was NOT expected when the shuttle was designed; the foam came in late in the game apparently. The tiles and wing structures were not designed with the intention of being struck by so much debris at such high speeds, and so initially the foam was seen as a real risk to the shuttle integrity. However, over the course of many launches, as the foam debris strikes piled up, it came to be an "expected" event, and the risk it posed was downplayed. And although you may "expect" a car with failing brakes to not crash everytime you move it, that doesn't mean you should drive it that way.
The mindset that foam was not likely to cause loss of structural integrity, was so strong for NASA shuttle managers that when the Columbia launched for the last time, they did not have a proper way to evaluate the extent of damage from foam. They had lots of data on small foam hits, and this was a BIG foam hit, and at very high speed. But since previous ones hadn't broken the shuttle, there was an "expectation" that even big foam hits probably wouldn't; they really weren't sure. The engineers obviously knew that F=ma could be a large number, even for small m, and they attempted to adapt some tools to calculate the possible damage. But the mindset that "foam is an expected event, it hasn't led to shuttle loss before" was already too well entrenched, and so the risk of wing impact damage was essentially dismissed.
This was made famously clear, when during the post-Columbia loss investigation, Scott Hubbard demanded that the foam gun tests be performed (ie. launching foam at a mock-up of the shuttle wing) in order to convince shuttle flight managers of the risk it posed. At that point, the majority of the investigation team already knew that the foam had been the cause and didn't press for those tests, but Scott knew the NASA culture, and knew they would not accept it unless proven beyond a shadow of a doubt. Against NASA's objections, the tests were performed, and we all saw the results.
It is important to remember that the exact same problem in mindset doomed the Challenger flight. The O-rings were not designed to allow any burn through of the rubber. When it started to occur, it was accepted as an inevitable consequence of launch, rather than a fatal design flaw. Because it had not burned completely through on previous flights, it was accepted that some burn through would happen, and not be catastrophic. NASA management downplayed the risk so much that even when engineers insisted that such a failure was more likely on a cold launch, their objections were not well understood. Burn-through was "expected", so how much of a risk could it be?
There is a lot to be learned about engineering, and management, by these examples. Engineering has been called the art of compromise. However, when so much compromise has been made, it becomes easy for people to not properly evaluate all the consequences. Meanwhile, management has pressures that go outside the engineering realm, and the psychology of that situation can lead to completely unrealistic assessments of risks and liabilities.
"It's overkill, of course. But you can never have too much overkill." - Anonymous Slashdot Coward
Better yet, wrap a long continuous thread (carbon fiber, kevlar, nylon, rayon, something) around the foam in a tight spiral wrap from top to bottom to secure the foam against the tank in addition to the adhesive holding the foam to the tank. It would be much harder for chunks of the foam to come off out from under the spiral wrap thread, and it would be lightweight and cheap too.
Example: Airbus' fly-by-wire system, designed to override a pilot when a dangerous decision was made, erroniously concluded a forest was a runway after a very low pass was made over it. Deciding the speed was too high, it cut the engines. Both pilots and something like 18 journalists were killed. Airbus blamed the pilots - a safe decision as the pilots couldn't answer back, being dead and all, and the only one they could have made. Blaming the computer could have put them out of business.
That would be a good story if you hadn't made it up. The pilot had slowed to near stalling speed
and realised too late he didn't have enough high t to clear the trees, he pulled back hard on the stick and went down into the trees. The computer didn't change the outcome one bit.