Slashdot Mirror
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."
So how are they going to ground the one in orbit?
The point is, now that we're looking intensely for problems in this area, we're going to find them. We're looking with eyes, cameras, satellites, lasers, sensors, robotic arms - all with unprecedented scrutiny. What do we expect to find? The shuttles are the most complicated pieces of machinery ever built, designed to launch into space with a controlled explosion, and then return to earth. Regardless of whether some here think the shuttle is junk, whether it's unnecessary, whether Air Force jocks doomed the program for the beginning, whether manned spaceflight is sentimental tripe, etc., the fact remains that flying something like the shuttle is a risky endeavor.
It's all about smart management of risk. Eliminating risk, especially for something like the shuttle, is impossible. This focus on debris falling from the shuttle is nothing more than a reactionary CYA tactic in the midst of a media circus in case something else like this were to happen again. Doing get me wrong: it's wise to consider the problem, to attempt to prevent it, and to ensure there is not undue exposure. But that exposure cannot be eliminated, and this intense focus on debris in particular beyond anything else, even in light of Columbia, is unwarranted.
NASA is operating in panic mode: one more catastrophic shuttle failure, and that's the end of the shuttle program, and essentially the practical end of the ISS and a lot of scientific research to boot. If you're paralyzed with fear, you're, well...paralyzed.
This New York Times article, which I posted in the previous article on this, sums up the situation quite nicely, for those who may have missed it.
Notable:
"How do you distinguish - discriminate - between damage which is critical and damage which is inconsequential?" asked Dr. David Wolf, an astronaut who spent four months aboard the Russian space station Mir. "We could be faced with very difficult decisions, in part because of all this additional information that we will be presented with."
"...the harder they look, they'll find more things."
"There is risk in anything you do."
July 27, 2005
Intense Hunt for Signs of Damage Could Raise Problems of Its Own
By JOHN SCHWARTZ
CAPE CANAVERAL, Fla., July 26 - Now that the Discovery is in orbit, the examination begins. Its 12½-day mission will be the most photographed in the history of the shuttle program, with all eyes on the craft to see if it suffered the kind of damage from blastoff debris that brought down the Columbia in February 2003.
There were cameras on the launching pad, cameras aloft on planes monitoring the ascent, cameras on the shuttle checking for missing foam on the external fuel tank, and a camera on the tank itself. One camera caught a mysterious object falling from the shuttle at liftoff; radar detected another, about two minutes into the flight. Cameras aboard the shuttle and the International Space Station will monitor the Discovery until the end of its mission.
But all this inspection may be a mixed blessing. The more NASA looks for damage, engineers an
Isn't that kind of hard to do with one of them already in orbit? I thought that the idea was that they could scramble Atlantis for a rescue mission if Discovery was seriously damaged...
Does that mean Discovery is Spaced?
Rock that crushes, Paper & Scissors that don't matter.
...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...
NASA is a failed government venture and has become a laughing stock and waste of american tax dollars.
we need to give money to the private sector if we ever want to advance in space.
if aviation had stayed strictly military air travel would never have been as available as it is today.
What do you suppose Burt Rutan could have done with that kind of funding? This is a disgrace.
NASA needs to re-adopt the paint on the external tank. At least on the shuttle side of the tank, the foam insulation needs a coat of paint to eliminate the porosity of the foam. That will lock the ice out of the foam and prevent it from tearing it off the tank.
The paint probably ought to be non-stick coated to inhibit excess ice formation too. Then put heaters in critical locations to break up the ice while the shuttle stack is sitting on the ground, or still moving at slow speeds. That way, supersonic chunks of ice won't go zinging into the shuttle body and we don't have to wonder if we've launched another one way mission to space.
Behold, this dreamer cometh. Come now, and let us slay him... and we shall see what will become of his dreams.
I think that Atlantis is in need of a new Zero Point Module before it can be used for any rescue missions.
(*Damn* I hate that show.)
I see it! I see it! http://i.a.cnn.net/cnn/2005/TECH/space/07/27/space .shuttle/top.shuttle.debris.jpg
See that red arrow? THAT'S what hit the shuttle!
The foam didn't even strike Discovery! It's just that it *fell off* at all, and the fact that everyone is paying attention to it now because of Columbia.
Yes, they'll be coming back. And no, it won't be particularly interesting if they land safely, because the foam didn't even hit the shuttle, not to mention that the shuttle has been hit by debris over 15000 times in the history of the program. Over a hundred tiles alone fall off and need to be replaced on every mission.
There's nothing interesting about this except the media circus. It's to bad they don't pay more attention to the *actual science* that NASA is doing with the shuttle, on this and the hundred-some other missions instead of obsessing over foam.
Let's see here: budget cuts, failing space program, failing economy, global criticism regarding human injustices abroad, rapid decrease of freedom and increase of governmental power...sounds alot like the SOVIET UNION doesn't it?
It takes just a moment and an action to destroy. It takes some time and thought to create.
I see it! I see it! See that red arrow? THAT'S what hit the shuttle!
This is why I always use blue arrows. Red arrows are dangerous.
-- Tigger warning: This post may contain tiggers! --
I guess you've never heard of an embedded system.
Those can't ship with bugs. Try applying a patch to several hundred 512 byte micros that are controlling the charging systems on the shock paddles in hospitals.
---
ECHELON is a government program to find words like bomb, jihad, plutonium, assassinate, and anarchy.
Jokes about the shuttle fleet being grounded while one is on orbit aside But I ... was just about to .. then you ... and I ...
You preempted my clever +5 Funny -- which I was all about to post with a high degree of self satisfaction -- in the first CLAUSE of your comment, DAMN YOU DAVE SCHROEDER, DAMN YOUUU!
Give the rest of us a chance at some karma, wouldja? ... I told them not to touch the red stapler ... then on Slashdot ... said to put the joke aside ... aside, I tell you ... going to burn down the server ...
The mission continues. Likely, if a problem surfaces, Atlantis would still be sent up after them. There's no sense in bringing down the orbiter until the assessments they already had planned for this mission can be completed. Right now, the shuttle does not appear to be damaged; it was a close call. Once Discovery lands, though, that's it until the tank's fixed.
Need A Shuttle Alternative
You see? You see? Your stupid minds! Stupid! Stupid!
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.
so, Thom Patterson - CNN reported last night that it was a 1.5" piece of tile. MARCIA DUNN, AP Aerospace Writer - on the yahoo! news - says that it's a "sizable chunk of foam insulation -- the very thing that doomed Columbia" - but then later says that it was indeed a 1.5" piece of tile while in the latest report from yahoo! it's simply "a large piece of foam insulation broke." interesting to see this evolve. at least it's not being sensationalized...
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
In response to an edict from the EPA, NASA was required to change the design of the thermal insulating foam on the shuttle's external tank. They stopped using Freon, or CFC-11, in order to comply with the 1987 Montreal Protocol, an agreement designed to head off doubtful prognostications of an environmental disaster. This resulted in 10X the level of tile damage since 1997 (when the new foam was implemented) per flight.
I hope this isn't what caused the damage we've seen lately, but if it is, it begs the question, is it worth using CFC-11 for safer shuttle flights given the relatively small number of launches that occur?
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.
...In Soviet Russia, the Buran fleet grounds you!
"42"
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.
In the mid-to-late 1980s there was a USAF program called NASP--National Aero-Space Plane. It was supposed to do exactly what you're describing.
NASP was eventually scrapped as "unworkable", and its successor project -- IIRC, the X-33 -- did not fare much better, even though it was actually built.
The short answer for why we haven't done it is "fuel is heavy." I'm not qualified to give the long answer, but a straight shot right into the atmosphere really is the cheapest way to get a given weight into orbit.
And, btw, the Space Shuttle *IS* hydrogen powered. The two solid-fuel boosters aren't, but that big foam-covered tank is just a shell carrying two parts H to one part O, which is what burns out of the shuttle's main engines.
5.3 VFI... (VERY Fuckin' Informative)
5.5 WFI... (Wayy Fuckin' Informative)
5.7 TFI... (Tooo Fuckin' Informative)
5.9 YBA... (Yo' Brains'll Asplode)
Not really.
The X-33 was over-budget, late, and suffering major development problems. The performance was getting worse and worse. And then you would have had to hope that Lockheed-Martin was willing to put up their portion of the funds to build the production booster.....
And, at the same time, Iridium was bankrupt, "Dark Fiber" was eating into comsat requirements, etc.
And worst of all the Skunk Works had said, "Hey, we've been building all kinds of classified stuff all these years. I know that nobody in the public field can make a multi-lobed composite hydrogen tank, but we can pull one off, winkwinknudgenudge" So when it was shown that they couldn't, people lost faith. Especially because the only actually novel, testable parts of it was that multi-lobed composite hydrogen tank and the linear aerospike... everything else wasn't going to be getting a proper workout because it wasn't going to have enough speed to really properly test the metal skinned TPS or much else.
The problem was the X-33 was the riskiest design of the three contenders. So it was mostly doomed from the start....
No, they'll probably figure out how to dust off the shuttle yet again and fly it. Remember, it's just the PAL ramp that's the problem, so they might just be able to change it to using a metal cover.
Gentoo Sucks
... is that the average slashdot poster is not as smart as a rocket scientist. :p
Close, but not quite.
The shuttle-as-the-second-stage-of-a-Apollo V was an alternative to the SRBs later in the design.
I liked that idea signifigantly better, because the Saturn V stage would have been useful for other things...
The shuttle was initially supposed to be all-reusable. Two shuttle-vehicles would launch together and one would go all the way to orbit and the other would go back to the ground. They could do it, but not in the budget given with the performance required. They could have made it smaller but fully reusable and in budget, or use a drop tank and make it bigger and stay in budget.
Gentoo Sucks
Was there any/much foam shedding prior to the removal of paint from the external tank?
Just wondering what the adhesive effects of all that white paint were.
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.
The foam in question insulates the disposable fuel tank so ice doesn't form on it. It does not reach orbit and is not part of the shuttle. The problem with the previous shuttle was that the foam hit the shuttle tiles as it fell off. Since this foam did not hit the shuttle, there is no problem with it.
Infuriate left and right
http://www.spaceflightnow.com/shuttle/sts114/05072 7palrampimages/
looks an awful lot like the unidentified chunk of debris that missed the starboard wing (scroll to bottom of link).
http://www.spaceflightnow.com/shuttle/sts114/05072 6images/
No, you are talking nonsense,
the entire reason for the shuttle was to make
frequent, 3 x weekly, launches, which it has never
done!
The design is a failure, that much is obvious,
what is not obvious is hou long the oversight,
which should come from the Congress will let this
waste of taxpayers money coninue.
If they cannot land the shuttle there's always the Space Station. This would mean up to seven new astronauts/cosmonauts in addition to the two already stationed there. In which case they'd run out of food and other resources pretty quick. The Russians would have to launch a Soyez to send provisions until they figure out how to get off that island.
"Now sit right back
and you'll hear a tale,
the tale of a fateful trip
That started from Cape Canaveral
abord this tiny ship.
The mate was a mighty sailerman
the skipper brave and sure
five passengers set sail that day
on a nine day tour
***
The weather was impeccable
but the insulation foam was lost
if not for the courage of slash dot chat
the Discovery would be lost..."
***
The crew set foot on the ISS
a small galactic isle....
[...what comes next?!]
The budget has gone up, not down. Further, tax revenues were will above expectations this year.
Failing economy
Unemployment is at 5%. You could possibly argue that the shit is getting ready to hit the fan, but most economist will disagree with you. It isn't the 90's, but it sure as hell isn't the 30's either.
global criticism regarding human injustices abroad
The global criticism around US human rights injustices doesn't even exist on the same scale as the Soviet Union. You would have as much luck comparing Texas executions to the Nazi holocaust.
rapid decrease of freedom and increase of governmental power
I am not sure what Soviet Union you are talking about, but the one I recall had a rapid INCREASE in freedoms and a rapid DECREASE in governmental power right before it all fell apart. Further, I would hardly call what is happening in the US a "rapid decrease in freedoms". The US still maintains extremely liberal speech and protest laws. Hell, I was in DC during the height of the anit-war protests, and the place felt more like a hippie commune then a Gestapo police state.
Um. No.
The US might be declining. It might fade away to something more like Britain. It will always be a power, but perhaps not THE power. It certainly isn't going to go like the Soviet Union though. The key difference between the US and all other "empires" is that the US has an extremely stable political system and civil society. Hell, it could be argued that the US has one of the MOST stable political systems in the world. The US might be young as a nation compared to Europe, but it has one of the worlds longest running continuous governments in the world. The US political system is so stable that nothing short of a nuclear holocaust could pull it apart, and if there is a nuclear holocaust in the US, you can bet some other place in the world is now the world's largest pane of glass.
The decline of the US is going to be very slow and very boring. The few territories the US holds are connected to the US only in that the US military will defend them. Other then that their governments are almost completely autonomous and could break off at any point. US military bases would be evacuated before they would fight over the land, as a base in the middle of hostile territory isn't worth anything anyways. I hate to dash your hopes, but the decline of the US is going to be dull.
The only possible exciting part would be a battle for Taiwan... but that would suck for everyone, even those not involved. The economic damage would make the fighting look like pocket change.
It's true. The SR-71, once in the air, has no fuel. The seals under the tanks can't hold with that massive amount of heat. It's leaking fuel as it takes off. Once in the air and at full burn, the titanium expands and fills in the cracks, but the SR-71 has to be refuled in-flight right after takeoff.
the root of Moores' Law states, fundamentally, that the more you use a technology, the better it gets.
Actually, Moore's law doesn't even directly talk about performance at all.
It is specific to integrated circuits and says that the complexity will double roughly every two years.
Complexity roughly corresponds to number of transistors which certainly roughly corresponds to performance.
See Wikipedia.
It would be if you put a SHUTTLE up there. Don't think anyone is going to be so foolish as to put a massive heavy lift launcher and a crew carrier in to the same vehicle any time soon.
The CEV designs and Kliper are pretty tiny compared to the Shuttle.
It would be totally OK to stap a heavy lift cargo carrier where the SHuttle is because you aren't going to have it reenter the atmosphere in most cases and if you did want to return something big to earth you wouldn't have a crew in it that would die if was damaged.
@de_machina
Astronauts are on government pay scales GS-11 thru GS-14.
The lowest step of GS-11 is $45K per year, the highest step of GS-14 is $99K per year.
Another way to look at it is that they do it in spite of the middling bucks, because that's the sort of person they are.
"Win treats sysadmins better than users. Mac treats users better than sysadmins. Linux treats everyone like sysadmins."
There's 2 kinds of software developer working in Washington State. Those with your attitude, live in Redmond. Those that know better, work for Boeing.
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.
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.
>You're limited in how much and what size by doing that. In case you all haven't noticed. The orbiter plus the solid rocket boosters form a powered triangle. A more stable formation for carrying a big load, say a telescope.
You're kidding, right, AC? The Shuttles can carry at most 28 tons of cargo. Saturn V could lob 118 into LEO. Proton can boost almost as much as Shuttle, for far less money, including a series of integrated space station components (Zarya, Zvezda, Mir baseblock). Maybe the trunnion pins were great for launching Hubble, but that is the exception. Your "triangle" thing doesn't make sense, inline thrust structure is more efficient, less mechanically complex and makes trajectory calculation simpler.
>And siting on top of a roman candle is safe?
Yes, comparatively. For manned flight, a rocket under the crew is far safer than having components next to them. Launch escape towers are safe, accurate tools for keeping crews safe from an exploding "candle". There is footage online of a Soyuz capsule popping off the rocket right above the pad, the rocket failed but the crew lived. The same can't be said for low-altitude launch problems with Shuttle.
Capsules, rockets and tugs for station components make sense. Buck Rogers spaceplanes don't.
gigantino.tv - Heavy but weighs nothing.
In fact, the EPA actually offered a waiver for NASA/Space Shuttle Program.
You can see a letter from NASA in response to the EPA firmly stating they *need* to continue to use CFCs for the Space Shuttle Program, specifically.
http://www.nasa.gov/pdf/45329main_hcfc4_001.pdf
It is advertising? "Buy our chips because in 18 months they will only be half as good as what we will have available then." Advertising?
--
WHO ATE MY BREAKFAST PANTS?
If we could just set up 24 hour video transmission of life on board the ISS after that shuttle docks. 9 astronauts, 1 Soyez for 3 passengers. ISS Survivor Reality TV.
IF we're talking of a saturn V, I don't think the shuttle would take the full stack to be workible, it would be more reasonible to me to delete the S-IVB third stage, and replace with a shuttle. With some modification to the shuttle, such as deletion of the main engines to save weight, i bet it would be awfully close to the mass of a loaded S-IVb.
Anyone have the raw numbers on this?
In either case, asymmetrical loading is as much of a dumbass idea as a topheavy model.
How about this idea: Redesign of the engines to accept hypergolic fuels, and trade ice and foam for dangerous chemicals, which the shuttle already has on board, admitedly in lower quanities.
The facts of the crash are not as cut and dried as either of you state and many are wrong. The pilot survived, along with most of the people on board, and was found guilty of manslaughter in the 3 fatalities connected to the crash. The funny thing is that two primary claims of the pilot in his defence were Operational Engineering Bulletins from Airbus Industrie regarding:
OEB 19/1 Engine Acceleration Deficiency at Low Altitude
OEB 06/2 Barometric Cross Setting Check
In a nutshell, the bulletins state that the engines didn't respond "normally" to throttle input and that barometric altitude indicator did not comply with airworthiness regulations. Air France chose not to share this information with the pilots. Naturally, this is the kind of thing that the data recorders could shine some light on. The data supported the claims that it was pilot error and the case was closed.
In 1998 it was determined that the data that was supposedly from the flight had been compromised. The flight data and cockpit voice recorders had been tampered with during a 10 day period when they were not in the hands of the magistrate's office. They were in the hands of the French Civil Aviation Authority (DGAC), contrary to their own regulations. The funniest thing is that one of the boxes presented as coming from the crashed A320 spontaneously changed its markings during the interim. An independent body from Switzerland determined that there had been a switch by comparing photos of the CVR being recovered from the crash site with the one presented as evidence.
While the "official" verdict was pilot error there is enough evidence to call that verdict into question. Who lost the least with the verdict? Airbus was introducing an advanced aircraft and attempting to challenge Boeing, and they were selling the "advanced" electronics of the 320 series: even admitting that there may be an issue with the system would have had devastating consequences.
The onboard computers did lead to a few incidents with the A320. In 93 a Lufthansa pilot made a landing with a very low sink rate, so low the flight computers would not allow the deployment of thrust reversers or brakes for a number of seconds. The plane ended up going off the runway. I guess you could make too soft a landing.
Admittedly they seem to have solved those problems, and I have no qualms flying in an Airbus but then again I flew Aeroflot a couple of times.
Check this link. There's a plenty of cool pictures available for free, just not on a CD. (hey, that rhymes :-)
I guess you've never heard of an embedded system. Those can't ship with bugs.
They can and do, as anyone who has ever used a flakey piece of such equipment can atest. The big diff is they usually just lock up or reset without any indication of what went wrong, so all you can do is curse and shrug. And buy a new product.
Now, embedded systems do tend to have higher standards of quality then, say, a word processor. I suspect that's due to a number of factors. One is mindset (people expect "computers" to be buggy these days, but not a stereo). Easy of fixing is another (it's easier to load a new patch to MS Word then to your microwave).
But the big reason is complexity. Simple systems are easier to build right then complex systems. You don't see many buggy coffee maker designs, because all a cofee maker has to do is get hot at the right times. Compare that to the hundreds of thousands of lines of code in many software projects...
There is a lesson here. Simple designs enable robust designs.
Of course, it is true that getting into space is a complex problem, but many argue that the STS is needlessly complex.
Some apt quotes (I'm a quote junkie):
"There are two ways of constructing a software design. One way is to make it so simple that there are obviously no deficiencies. And the other way is to make it so complicated that there are no obvious deficiencies." -- C.A.R. Hoare
"A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away." -- Antoine de Saint-Exupery
dragonhawk@iname.microsoft.com
I do not like Microsoft. Remove them from my email address.
... Fuel costs are a low % of the total cost of each launch. So optimizing things to reduce fuel costs is almost a waste of time.
The goal was to build something so you could just refuel it each time you want to send it up thus saving a lot of $ but a large % of the ship is not reusable and they have to inspect / disassemble the rest of the thing each flight which is why it's so expensive. They should have build a ship that can do low temp reentry and can do horizontal takeoff and landing not some sort of rocket where you have to rebuild build 90% of it for each launch.