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Albert Einstein reportedly said,
"You do not really understand something unless you can explain it to your grandmother." It may sound excessive, but remember that's what Feynman did with advanced theoretical physics.

I think it sounds excessive. Also, Feynman could not explain his father where photons come from.

That's just silly, every single article you link to. The specs for the code were such that there would be no year-end-crossing missions, that's all there is to it. This has nothing to do with when was the flight software designed in. It simply wasn't in the specs back then, and there was no funding to change it any time earlier than when they did actually change the specs and implemented it. You're providing a straw man for an argument. Space Shuttle's flight software was probably the best engineered piece of software there ever was. See here. Or we can cite Feynman, who had quite low bullshit threshold and would not be impressed if there was nothing to be impressed about:

The software is checked very carefully in a bottom-up fashion. First, each new line of code is checked, then sections of code or modules with special functions are verified. The scope is increased step by step until the new changes are incorporated into a complete system and checked. This complete output is considered the final product, newly released. But completely independently there is an independent verification group, that takes an adversary attitude to the software development group, and tests and verifies the software as if it were a customer of the delivered product. There is additional verification in using the new programs in simulators, etc. A discovery of an error during verification testing is considered very serious, and its origin studied very carefully to avoid such mistakes in the future. Such unexpected errors have been found only about six times in all the programming and program changing (for new or altered payloads) that has been done. The principle that is followed is that all the verification is not an aspect of program safety, it is merely a test of that safety, in a non-catastrophic verification. Flight safety is to be judged solely on how well the programs do in the verification tests. A failure here generates considerable concern.

To summarize then, the computer software checking system and attitude is of the highest quality. There appears to be no process of gradually fooling oneself while degrading standards so characteristic of the Solid Rocket Booster or Space Shuttle Main Engine safety systems. To be sure, there have been recent suggestions by management to curtail such elaborate and expensive tests as being unnecessary at this late date in Shuttle history. This must be resisted for it does not appreciate the mutual subtle influences, and sources of error generated by even small changes of one part of a program on another. There are perpetual requests for changes as new payloads and new demands and modifications are suggested by the users. Changes are expensive because they require extensive testing. The proper way to save money is to curtail the number of requested changes, not the quality of testing for each.

One might add that the elaborate system could be very much improved by more modern hardware and programming techniques. Any outside competition would have all the advantages of starting over, and whether that is a good idea for NASA now should be carefully considered.

(emphasis mine)

however note those words were written in 1916 and education standards are somewhat lower now

Do you have a citation for this? I think today's college matriculant tends to have a better understanding of mathematics than in the early 20th century.

Certainly, over a much smaller number of samples and time period, Feynman disagreed with you.

Edward Tufte makes a convincing argument that if they had been better able to present and communicate their ideas they would have been able to make their engineering point in an understandable way and saved lives.

Lies. Lies. Lies. Lies. Lies.

The space shuttle Challenger exploded, killing its crew, not because engineers had failed to communicate the dangers, but in spite of their warnings. NASA management simply refused to listen to what the engineers were telling them. Read Feynman's lucid assesment of exactly what went wrong at NASA. Here's a relevant excerpt

Finally, if we are to replace standard numerical probability usage with engineering judgment, why do we find such an enormous disparity between the management estimate and the judgment of the engineers? It would appear that, for whatever purpose, be it for internal or external consumption, the management of NASA exaggerates the reliability of its product, to the point of fantasy.

And this report is coming from a scientist.

Modern managers and executive peddle in lies, exaggeration and general bullshit. It is the hallmark of their profession. Engineers and scientists by contrast deal in precisely the opposite commodity; they seek the truth. Assessments like the MIT application essay allow bullshitters to shine bright under the floodlights of meaningless prose, while shunning the real technical ability and merit of people who actually understand and can do things.

If there were less such opportunities for charlatans to shine, and more testing of real skills, there would be a lot less Challenger disasters and accidents like them.

Except the sheep and wolf analogy has an implied zero-sum notion to it. From our fairy tales and such we think of the wolves as nasty evil creatures, but seriously look at nature: they fulfill a role in the ecosystem and are simply a part of it.

They way I would answer your question is to say we are all wolves and we are all sheep, and the analogy is simply way off mark. Do you seriously think it wise to micro-manage every aspect of the entire economy according to some predefined notion of fairness? Because that sounds like what you are implying. Its a well worn argument but I'll say it anyway: It didn't work for the Soviets, and it didn't work for the Chinese.

The real problem as I see it is already perfectly summed up in Feynmans famous appendix to the Challenger report. The real problem is we have developed highly complex financial systems that more or less require a postgraduate degree in mathematics to understand, I'm willing to bet the vast majority of people making the decisions (not the models) that led us into the current crisis had little to no real understanding of what they were dealing with, and as such they exaggerated the (lack of) risk to suit their managerial requirements. Precisely as occurred in the Challenger disaster and precisely as Feynman went to great pains to describe.

There is no vast conspiracy of criminal selfishness, no wolves and sheep, just a bunch of people working with complex mathematical constructs and absolutely no idea of how they work. The sort of PHB fuckup that most slashdotters should readily understand.

Capsules don't rely on tiles but instead use single-ablative shields that are protected during the entire flight until reentry.
After each launch the shuttle has to be completely rebuilt so there weren't any cost savings.
A little more about problems with the shuttle design by a Nobel-Prize winning physicist....

http://www.fotuva.org/feynman/challenger-appendix.html

Foam coming off the tank because of improper application; deficiencies in the materials used; degradation during its transport to the Cape; the loading of supercold fuels; and the violent ride to space. Florida Today reported earlier this year that foam came off the tank on at least 71 flights to date, but NASA did not consider the resulting damage to the heat shield a safety issue.

Requirements and specifications not being followed in testing and manufacturing of the external tank.

Loss of institutional knowledge and experience at NASA and the Michoud plant because of "lots of old-timers retiring or taking buyouts" as the shuttle program reduced its workforce throughout the latter half of the 1990s.

NASA's limited insight into changes vendors had made with materials used in making the tanks.

Environmental requirements requiring removal of freon from the process for spraying the foam insulation onto the tank. NASA has said that the freon-free application method resulted in foam that initially did not adhere to the tank as well, but changes were later made to strengthen the bond of the environmentally friendly foam.

In this wikipedia article, it gives a reference to this snippet of Feynman's text which "Describes why element 137 is the last classically stable element."

So I guess the answer is that an ion is not a 'classically stable element'.

Maybe you can only have positive ions of elements above that, but they'd still be atoms of those elements.

"In fact, about the only thing that the number relates to at all is the room in which the great physicist Wolfgang Pauli died: room 137."

Uh...Pauli Exclusion Principle? Uhh...yeah. Schroedinger must be having a cat.

We signed on for a series of disasters when the Shuttle Program was started in 1970 more or less. See Richard Feynman-Personal Observations On The Reliability Of The Space Shuttle, The damn thing has never come close to meeting its cost, usability, and reliability goals and has no meaningful mission other than completion of the more or less worthless International Space Station. When last I looked, the Hubble service mission was still cancelled. It's the only thing on Shuttle agenda that seems to me to justify any risk at all to human life and what remains of space program support.

We either ought to admit that both the Shuttle and the ISS were mistakes and scrap both programs right now (my vote). Or accept the risk of launching a vehicle that will never be especially safe and get on with it. Odds are actually pretty good that it will make it back safely, and there seems to be next to nothing other than the obvious things like not launching during thunder storms that can be done to materially improve those odds.

The usual way that such engines are designed (for military or civilian aircraft) may be called the component system, or bottom-up design. First it is necessary to thoroughly understand the properties and limitations of the materials to be used (for turbine blades, for example), and tests are begun in experimental rigs to determine those. With this knowledge larger component parts (such as bearings) are designed and tested individually. As deficiencies and design errors are noted they are corrected and verified with further testing. Since one tests only parts at a time these tests and modifications are not overly expensive. Finally one works up to the final design of the entire engine, to the necessary specifications. There is a good chance, by this time that the engine will generally succeed, or that any failures are easily isolated and analyzed because the failure modes, limitations of materials, etc., are so well understood. There is a very good chance that the modifications to the engine to get around the final difficulties are not very hard to make, for most of the serious problems have already been discovered and dealt with in the earlier, less expensive, stages of the process.

The Space Shuttle Main Engine was handled in a different manner, top down, we might say. The engine was designed and put together all at once with relatively little detailed preliminary study of the material and components. Then when troubles are found in the bearings, turbine blades, coolant pipes, etc., it is more expensive and difficult to discover the causes and make changes. For example, cracks have been found in the turbine blades of the high pressure oxygen turbopump. Are they caused by flaws in the material, the effect of the oxygen atmosphere on the properties of the material, the thermal stresses of startup or shutdown, the vibration and stresses of steady running, or mainly at some resonance at certain speeds, etc.? How long can we run from crack initiation to crack failure, and how does this depend on power level? Using the completed engine as a test bed to resolve such questions is extremely expensive. One does not wish to lose an entire engine in order to find out where and how failure occurs. Yet, an accurate knowledge of this information is essential to acquire a confidence in the engine reliability in use. Without detailed understanding, confidence can not be attained.

A further disadvantage of the top-down method is that, if an understanding of a fault is obtained, a simple fix, such as a new shape for the turbine housing, may be impossible to implement without a redesign of the entire engine.

True, the J-2 is older and less-efficient, but it's a much simpler, more reliable design than the SSME.

The SSME is much more intricate, tempermental, expensive and operates at much, much higher pressures than the J-2. The reliability of the SSME in the Shuttle is more a tribute to the army of inspectors employed by NASA than to its inherent design.

Personally, if I were trusting my life to a new rocket , I'd prefer to sacrifice a little ultimate efficiency for an engine that has reliabilty designed in, not inspected in.

Not true - the SSME is more reliable than the J-2 and is in fact the most reliable booster engine ever built. There have never been any SSME in-flight failures and the SSME system has logged around 1 million seconds of hot fire time, the equivalent of over 600 3-engine missions.

But for a dose of reality, see: http://www.fotuva.org/feynman/challenger-appendix. html

The Challenger disaster sparked a lot of insightful commentary about the shuttle program from Richard Feynman.

The Rogers Commission relegated the bulk of his thoughts to an "Appendix" because no one wanted to release a report that was too critical of the space program (even though that's exactly what they were appointed to do). It almost wasn't included at all, but for Feynman's dogged insistence.

He deals with his role in the Rogers commission in No Ordinary Genius (that's a link to the beginning of the Chapter from Google Print).

That chapter is filled with funny anecdotes, and enraging stories about the bullheadedness of beaurocracy, told by one of the most charismatic geniuses of our time about one of the most important events from my childhood.

Highly recommended.

The Challenger disaster was quite shocking, even more so when I realised that the crew were probably alive (if not conscious) all the way until their capsule hit the ground. It's incredible that something could survive that disintegration but very sad that there was no way to get the capsule safely back to earth.

Richard Feynman's report is a fantastically clear and lucid account of his opinions. The man was one of the greatest communicators of science, and after reading this, you will see why. The most astonishing bit is that he discusses some less than simple things in such a way as to make them easily understood. It's a model of clarity, and I recommend it.

On the solid rocket booster: A more reasonable figure for [reliability of] the mature rockets might be 1 in 50. With special care in the selection of parts and in inspection, a figure of below 1 in 100 might be achieved but 1 in 1,000 is probably not attainable with today's technology.

On the main engine: Engineers at Rocketdyne, the manufacturer, estimate the total probability [of shuttle main engine failure] as 1/10,000. Engineers at marshal estimate it as 1/300, while NASA management, to whom these engineers report, claims it is 1/100,000. An independent engineer consulting for NASA thought 1 or 2 per 100 a reasonable estimate

So, how exactly does this make a safe, reliable launch system?

Read Richard Feynman tearing them a new one over exactly that sort of language. It's disheartening that they still apparently have marketdroids doing their press releases.

but the math is high school

If that's the case, then NASA needs to go back to high school.

Let's hope these are more realistic calculations than they did on the Columbia and Challenger statistics...

The one obstacle I seem to remember, and Feynman refers to is the Shuttle computers are short on memory. One of the main roles of the humans on board is about 4 times a mission to load the next part of the mission in to the computers from tape, punch a button and make it go.

Now maybe you could load one profile in for launch and then the ISS crew could load another to reenter. If the mission has to abort before it docks with the ISS you would need to insure the computers have the program for the abort and reentry without human intervention.

A big hurdle is I don't think the shuttle is designed to auto dock with the ISS, though I could be wrong. The Russians are lot fonder of auto docking than the Americans. If it can't do it now it would take a lot of R&D and a pretty dangerous first test flight.

The Shuttle does let the human take over for the vary last part of the landing but that is really totally to indulge the ego's of the pilots on board. I wager a computer could do it better and more consistently than the humans barring equipment failure. Some humans do it better than others.

A question is why would you want to fly it unmanned other than to not risk lives. You still don't want another catastrophic failure of a Shuttle because that would probably devastate the program even if it was unmanned. If you lost a shuttle with a key ISS component in it during launch that would devastate completion of the ISS too. Loss of life of astronauts is a bit overrated. They know its dangerous and they will still do it. No point in needlessly risking their lives but its a bit silly to stop them flying all together too.

"The foam has fallen off on all 200 some flights"

I think its more like 114 flights.

Do you work for NASA? They said the same thing and used it to rationalize doing nothing about it until Columbia. They were really panicky about it when they saw tile damage in all the early launches, but hey they landed OK. After a while since they kept getting away with it they made the assumption it was OK. They were wrong. There is a scathing indictment of your attitude by Feynman.

Basically NASA was shooting craps with the foam because its always been dangerous and on Columbia they rolled snake eyes.

Space flight IS dangerous but that is no reason to let fixable problems that heighten that danger go unfixed. The only contradiction to this point is the foam and tile damage may not be fixable. They may be a fundamental design flaw which means you either abandon the design or keep shooting craps.

Dude I read the article you didn't need to repeat it. You and he are still totally missing the point.

For NASA to just now be attempting to get it "right", and doing test flights, 114 missions in to a 130 mission program is pathetic, its not something to be praising them for. They should have fixed all of this crap back when they WERE test flying it and before it killed people. They KNEW all this debris and tile damage was a problem but as long as they got away with it they talked themselves in to saying it must be OK. WRONG, BAD, BAD MANAGEMENT.

They pretty obviously ignored another known problem in the foam this time around so they still didn't get this test flight right, leading to another long grounding and no doubt another test flight, or who know how many more test flights. At over a billion a pop for these test flights a for a program struggling to survive they REALLY needed to nail this flight and they obviously didn't.

"This kind of thing is why the general public needs a bitch-slap. They never listen."

Thats an elitist thing to say. I think the public is starting to listen damn well for the first time. They aren't listening to shuttle management anymore because they have zero credibility. Read Feynman's rant about shuttle management saying the risks for various Shuttle failures were 1 in 100,000 when in fact they were more like 1 in 300 by any scientifically based measure.

The general public and me and everyone else ranting about this are the ones in the right here. The Shuttle and ISS programs have been messed up for the duration of their existence. People like you and this guy keep making apologies for it and saying how it really isn't as bad as it seems, when in fact it IS as bad as it seems and the public should have demanded better a LONG time ago.

I realize the STS fleet is aging, but still, it almost sounds like they've been incredibly lucky 100 times and haven't spotted the flaws until now, which sounds quite incredible.

It may have been that low, but post-Challenger I believe it was closer to 1 in 25, much of it due to the SRBs and Air Force history with SRBs. Note the Air Force only really cared deeply for the first 125 seconds as that is when it posed a risk to the American public and fell within the 'launch category' that the Air Force is responsible for. So that 1 in 25 for early Shuttle launches really only applies to the first 125 seconds. Landing was entirely NASA's purview. A good deal of it is also due to the main engines as well. See this web site Also this was earlier in NASA's history, when they had much fewer launches. Air Force has adjusted their earlier estimates to lower failure rates due to Shuttle successes. Two failures in 113 launches, in manned spaceflight, is actually pretty damn good. If NASA had better management, they could have achieved 113 successes in 113 launches.

The famous physicist Richard Feynman, who was on the investigation panel after the Challenger explosion, estimated the failure rate to be "of the order of one percent", or 1 in 100. when at the time NASA management (not the engineers) had been claiming a rate of 1 in 100000. He based his reasoning on estimates of the failure rates of the individual subystems. You can read his arguments here.

Looking for this?

Because of the enormous effort required to replace the software for such an elaborate system, and for checking a new system out, no change has been made to the hardware since the system began about fifteen years ago. The actual hardware is obsolete; for example, the memories are of the old ferrite core type. It is becoming more difficult to find manufacturers to supply such old-fashioned computers reliably and of high quality. Modern computers are very much more reliable, can run much faster, simplifying circuits, and allowing more to be done, and would not require so much loading of memory, for the memories are much larger.

For whatever it's worth, a 1985 mission (also by Challenger) suffered a mid-ascent center-engine failure which resulted in a lower-than-expected orbit. Not every engine failure results in a catastrophic loss. There have also been a number of launchpad aborts after the main engines have started but before the SRBs ignited.

What do you mean, current problems in the US space program? AFAIK, the space shuttle's success rate is on par with the expectations.

Calculations showed otherwise, and things proceeded as expected. (Note: this may be apocrypal, as I can find no google reference to it and can't remember where I came across it -- but it makes the point as well as anything)

Just imagine if the theories or calculations had been inadequate to predict the results. Then look across the expanse of scientific history, and see how much of scientific knowledge has sprung from unexpected or unforeseen results.

All the author is saying is that the price of poker has gone up, and as we continue to push back the frontiers of ignorance, it's pretty much inevitable that we're going to step in something really ugly sooner or later. And with the capabilities humanity is poking at with sticks, the consequences of a major oops/surprise in a number of fields (high-energy physics, genetic tinkering/biowar, nanotech) are generally at least planet-wide in scope.

For the concerns involving alterations in the fabric of space-time or nature of reality, even off-world laboratories may offer insufficient protection.

Risk assessment is a very poorly understood discipline, easily corrupted by those who want to attain the goal and can't conceive of making a mistake. Look at how easily the NASA bureaucrats rationalize away the risks of the shuttle -- check out Feynman's appendix to the Challenger failure analysis report for some insight, and marvel at how his back-of-the-envelope calculation of 1:100 catastrophic failure rate still holds true today, and NASA management is still oblivious to the point he was trying to make.

Why risk precious lives if we could do it simply using better technology. IMO manned space exploration is a relic from the Cold War. I hope the NASA really learnt from Feynman's words.

First, there's the well-documented high failure rate of launch vehicals -about 5% for the US, 10-20% for rest of the world. This figure doesn't include experiments or tests.

Second, the atmospheric reentry of one lost rocket schlepping clicking-hot material up the well can lead to the atomization and dispersal of that material in the atmosphere, transforming the earth into a mutants' menagerie.

The Space Shuttle has experienced a lower failure rate than the rest of US launchers, about one in one hundred.

There was an uproar a few years ago, about the Cassini probe. That probe, containing over 32 KG of plutonium, was lifted by a launcher which, at the time, had a one in twenty failure rate, and was due for another.

Additionally, there have already been three catastrophic failures of launchers with plutonium-containing payloads, resulting in world-wide atmospheric dispersal of a hundreds of curies worth of plutonium.

Personally, I don't have a problem with the idea nuclear power or fission-powered space travel. But there remain serious development before it becomes considerably safer. This isn't a marketing campaign, you can't convince knowledgeable people with images of spouting teapots, not when life on this planet is at risk. Nor will risk management white-wash keep people from realizing there's a definite, likely risk that people will die from an accident. [I work in risk management.]

So, what's more important, do we need to do this now, now, now? Or can it wait a decade or three, until we have nuke power better figured out? My vote is to wait a bit.

An interesting read -- for those of you who haven't seen it is the Appendix written by Feynman to the Challenger Report (otherwise known as the Rogers Commission Report).

see http://www.ralentz.com/old/space/feynman-report.ht ml
or
http://www.fotuva.org/feynman/challenger-appendix. html