Apollo 11 Lunar Lander Pre-Launch

[MBDK]

He's trying to set the stage for a drama in which we're all just good ol' boys sitting around, having a few beers, and talking about space.  In that scenario the conversation should be light and congenial, not confrontational.

I can only speak of my own experience with my own personal friends who have technical and degreed qualifications.  When we sit around and discuss such subjects, although the mood IS light and congenial, there is NOTHING we like better than to show there is a fallacy in one or more of one another's views/ideas/statements.  We don't just pat each other on the back and follow some imaginary "official" doctrine.  We imagine. postulate and debate what is and what could be.  Although beer's influence and flights of fancy are integral components of the evening, logic and scientific facts are what ultimately rule.  If, when conclusively shown their failure(s) in such a debate, any one of us acted as immature and boneheaded as JRK (I do believe his initials are a hint) has, we would be rightfully ostracized.  It takes a little personal integrity to admit one's mistake(s).  My good friends have that quality.  JRK has shown no inkling of such, to date.

Note:  Edited for punctuation.

[nomuse]

Hrm. Maybe because I've just been thinking of how planning can reach a point of diminishing returns (I assume engineers have a way of identifying that point. I've never found a good one). But it strikes me at this moment that the only utility to drilling down -- to iterating on a claim made by a hoaxie -- is because the subject is interesting.

An average, neutral person (whatever the heck either of those are supposed to mean), when presented with a top-level claim/rebuttal about the purported Apollo Hoax, will realize one is better constructed, better supported, and more probable than the other. "There should have been stars!" "Film has a dynamic range."

The hoaxie that drills down, moving the goal posts or outright changing the character of their claim or throwing up all sorts of chaff in an attempt to find wriggle room...well, it really doesn't matter how many times you work the point/counterpoint, how deep you nest in ever more subtle aspects of the problem, they've proven themselves unreachable at that moment.

[mako88sb]

And once again, please show us how your evidence supports your claim that steering dynamics of the LM in solo flight were significantly altered by the addition of plume defelctors, or at least altered such that instability was a real concern.

Again, here is the equation you brought to the table:

M_+X = 89D₁ - 59D₂

The instability that leads to a positive feedback loop is only present when M_+X is negative, as stated in the memo. You agree with that, yes?

I don't think he does.  Which is to say I don't get the impression he thinks one can compute stability, or that it makes sense to do so.  I don't think he considers free-body dynamics to be a computable regime.  This is something I run into all the time with hoax claimants trying to bluff their way through specialized knowledge.  They usually don't know what's possible.  Their extrapolation from intuition usually goes down the wrong path. 

Best example I've seen is your thorough dismantling of blunderboys attempt to prove that NASA was reckless with the Apollo missions because of the strong likelihood, his opinion, of a solar event happening that would expose the astronauts to a lethal dose of radiation over at the now shut down IMDB forum. You could tell he was pretty well foaming at the mouth because he was obviously losing and unable to properly answer your pointed questions. Btw, do you have a copy of that exchange? I know it was long but it was great throwing that in his face back on some youtube videos he left messages on.

[molesworth]

It's a mathematical expression of how we observe the universe to work.

This one sentence sums up the scientific and engineering approach which HBs and conspiracy theorists often have problems understanding.  It doesn't matter whether it's LM stability, orbital mechanics, radiation exposures, or onward to flat earth and Planet X conspiracies, the mathematical models can be used to demonstrate when the beliefs are wrong (or right!) and what the effects of various changes to the parameters would have.

Mathematical models are a fundamental part of the scientific method, and help in the development of testable theories.  The models are based on "how we observe the universe to work", and are refined and improved through repeated experiment and observation.  And in this case we have a simple equation which can tell us about the stability or instability under different conditions.

My point (since I'm sure most are already aware of the role of maths in science) is to ask JRK why he is avoiding answering questions about the use of this equation, and whether he thinks mathematical modelling is a valid approach to dealing with this type of question.

[smartcooky]

An average, neutral person (whatever the heck either of those are supposed to mean), when presented with a top-level claim/rebuttal about the purported Apollo Hoax, will realize one is better constructed, better supported, and more probable than the other. "There should have been stars!" "Film has a dynamic range."

Its a matter of expectations...

If the astronauts came back from the moon and showed me this photograph they took there with a film camera...



...I would have no reason to believe there was anything wrong. As a photographer and photo processor, I would expect such a photograph to look like this, given the known dynamic range of film stock. However, if they show me this photograph...


   
... and claim it was taken on the moon, and I will become deeply suspicious. I will want to know where they obtained a film with such an enormous dynamic range; a film characteristic that has so far been impossible to obtain.

[bknight]

And once again, please show us how your evidence supports your claim that steering dynamics of the LM in solo flight were significantly altered by the addition of plume defelctors, or at least altered such that instability was a real concern.

Again, here is the equation you brought to the table:

M_+X = 89D₁ - 59D₂

The instability that leads to a positive feedback loop is only present when M_+X is negative, as stated in the memo. You agree with that, yes?

…

And in his version, one can never know whether one has achieved stability except by demonstration flight.  The problem is solvable practically, but not prescriptively.  This is why we keep pushing the math under his nose and he just keeps trying to figure out how it applies.  It hasn't sunk in that there is a formalized model for this, and that math solves the problem in the abstract, not just individual cases.  He hasn't figured out that engineers can know there will be no stability problem (or, as in the memo, that a certain curious condition will arise in remote circumstances) by working it out on paper.  He doesn't see how math solves what he thinks is a purely practical problem.  The plume deflectors weren't flight-tested, so in his limited pseudo-engineering world they were untried.

We generalize the problem of free-body dynamics for most practical purposes using what's called a linearized state-space model.  It's "linearized" in the sense that all the familiar Newtonian elements of the problem are represented as entities in linear algebra -- matrices and vectors.  More accurately, many elements of the problem are matrix- or vector-valued functions of some other variable such as time.  It's a "state space" in that it's a vector space of all possible inputs, outputs, and states (and their derivatives) that a system can be in, as represented in linear algebra terms.  Ironically, the state-space class of mathematical solutions is also used in econometrics.

The beauty of such a system is that all possible effects are correctly modeled using a homogeneous (and small) vocabulary.  You can abstract concepts like body axes and control axes -- and in the LM's case the control axes don't even have to be orthogonal (at right angles).  Everything boils down to multiplying vectors and matrices.  That's what linear algebra is for.  A layman is probably not going to stumble onto this by himself.  He was either taught it and thereby understands its power and simplicity, or else his concept of the quantitative nature of the problem is likely to be a bewildering melange of special-case formulations that would quickly become intractable for such a problem as controlling a spacecraft.  In this system, the center of mass not being at the center of the control axes isn't a problem, because it's never assumed to be.  Transforming between body axes and control axes is straightforward and never omitted.  There are no special cases to consider.  And the transformation can even be a time-parameterized function (or a function of some other variable such as fuel-on-board) with no loss of elegance.

With these techniques, the additional effect of plume impingement on the deflector simply becomes another vector in the problem, no different than the direct effect of the jet itself.  It has discoverable, deducible physical properties, and these properties can be modeled easily in the language of linearized state spaces.  The equation above is merely a matrix multiplication rendered out in its scalar decomposition.  The fact that it also works out to be the definition of toque (a quantity of force acting a distance from the center of mass) is intentional.  Torque is not some contrived concept.  It's a mathematical expression of how we observe the universe to work.  The algebraic equivalence between the basic expression of the concept and the model we use validates the model.

Apparently unaware of this, Jr not-Knowing figures that the engineers who came up with the plume deflector had no way to determine its effect on the control problem before flight.  And in his world of perfectly-balanced jets and perfectly-located centers of mass and idealized structure, any disruption is disastrous.  And if we can't see this, then we're just not at his level of understanding.  (Well, that's true.  But not in the way he wants.)  The central theorem of state-space dynamics is not that a system rests at equilibrium or returns to it unaided, but rather than a system can be driven to a desired state deterministically.  The whole science of control theory would be obviated entirely if everything worked the way Jr Knowing imagined it does.

And that same misconception is behind the bravado with which he insinuates that we can't know that we're right and that he's wrong.  Yes!  Yes, we can!  The same math by which the engineers originally determined the effect of the plume deflectors and predicted its feedback loop in extraordinary circumstances works just as well for us in determining that no possible location of the LM's center of mass in solo flight reverses the relevant moment.  No, we aren't just gullible or brainwashed.  I know what I know.  I know why I know it.  I know that it works because I see it work.  It's not just a thing I read, or a thing someone told me.  And I'm not alone.  These are common techniques, widely known and broadly applicable.  Jr's ignorance of them doesn't make them invalid, doesn't make them go away, and doesn't make him the insightful genius he hopes to play.

And this is why plume deflectors were added with the knowledge that they won't have an impact of the control/stability of the LM.  Poor jr does not have knowledge about the math and how it proves the concept.  And because he is too hard headed to admit so, he continues the "I have issues believing".

[JayUtah]

I assume engineers have a way of identifying that point.

We do; it's called a deadline.   

All seriousness aside, no we don't.  In fact, that's one of my interview questions for engineering managers.  It's a trick question in a sense because unqualified candidates think they have a universal answer.  We quip that a project in design engineering has two phases:  too early to tell, and too late to do anything about it.  There is no hard-and-fast point where you markedly shift the approach.  Analysis at the beginning of a project is proven to have the greatest effect on cost and complexity, but it happens before enough of the problem has been explored to really know what to analyze.  It's the manager's job to break the "analysis paralysis" that occurs from trying to reason conclusively with too little data, and then to get the ball rolling.

The "correct" answer to the LM's problem that the plume deflectors were added to solve would have been to take the LM back to its conceptual mechanical design stage and weigh more heavily the jet duty cycle with its thermal effects.  Then the jets could have been positioned to avoid thermal loads on structure over the firing times it became apparent later were wanted for mission planning.  But then you would have had just another set of problems that arose from that systemic arrangement that weren't present in the LM that flew.  The urge to analyze extensively follows the natural urge to find an optimal solution.  In any significant engineering problem there simply does not exist an optimal solution.  The engineer and author Henry Petroski coined the term "satisficing" to address this.  Engineering problem spaces are defined by opposing variables that are always in conflict, always in tension.  A solution for these variables is ever only "good enough."

The hoaxie that drills down, moving the goal posts or outright changing the character of their claim or throwing up all sorts of chaff in an attempt to find wriggle room.

Which they will eventually find, since no engineering survives all conceivable criticism.  But the key is to determine at what level you've found something that merits criticism and how consequential that is to questions like that of authenticity.

[JayUtah]

Btw, do you have a copy of that exchange?

I don't, and I understand it's gone entirely from IMDB now.

[smartcooky]

Btw, do you have a copy of that exchange?

I don't, and I understand it's gone entirely from IMDB now.

Jay

Can you remember what year this was, and what section the discussion was in?

Did you use jayutah or some other username?

What username was the blunder using?

I am prepared to have a trawl through some internet archives to see if I can find it, but I would like some kind of starting point.

[apollo16uvc]

An average, neutral person (whatever the heck either of those are supposed to mean), when presented with a top-level claim/rebuttal about the purported Apollo Hoax, will realize one is better constructed, better supported, and more probable than the other. "There should have been stars!" "Film has a dynamic range."

Its a matter of expectations...

If the astronauts came back from the moon and showed me this photograph they took there with a film camera...



...I would have no reason to believe there was anything wrong. As a photographer and photo processor, I would expect such a photograph to look like this, given the known dynamic range of film stock. However, if they show me this photograph...


   
... and claim it was taken on the moon, and I will become deeply suspicious. I will want to know where they obtained a film with such an enormous dynamic range; a film characteristic that has so far been impossible to obtain.

If the hoaxers have such a film stock to get the latter images... they should give Kodak and call and the will receive a blank cheque!

[Peter B]

I assume engineers have a way of identifying that point.

We do; it's called a deadline.   

All seriousness aside, no we don't.  In fact, that's one of my interview questions for engineering managers.  It's a trick question in a sense because unqualified candidates think they have a universal answer.  We quip that a project in design engineering has two phases:  too early to tell, and too late to do anything about it.  There is no hard-and-fast point where you markedly shift the approach.  Analysis at the beginning of a project is proven to have the greatest effect on cost and complexity, but it happens before enough of the problem has been explored to really know what to analyze.  It's the manager's job to break the "analysis paralysis" that occurs from trying to reason conclusively with too little data, and then to get the ball rolling.

The "correct" answer to the LM's problem that the plume deflectors were added to solve would have been to take the LM back to its conceptual mechanical design stage and weigh more heavily the jet duty cycle with its thermal effects.  Then the jets could have been positioned to avoid thermal loads on structure over the firing times it became apparent later were wanted for mission planning.  But then you would have had just another set of problems that arose from that systemic arrangement that weren't present in the LM that flew.  The urge to analyze extensively follows the natural urge to find an optimal solution.  In any significant engineering problem there simply does not exist an optimal solution.  The engineer and author Henry Petroski coined the term "satisficing" to address this.  Engineering problem spaces are defined by opposing variables that are always in conflict, always in tension.  A solution for these variables is ever only "good enough."

The hoaxie that drills down, moving the goal posts or outright changing the character of their claim or throwing up all sorts of chaff in an attempt to find wriggle room.

Which they will eventually find, since no engineering survives all conceivable criticism.  But the key is to determine at what level you've found something that merits criticism and how consequential that is to questions like that of authenticity.

In reading this answer, I'm reminded again of Murray & Cox's description of Joe Shea's approach to managing the design of the Apollo and Saturn spacecraft. He used as his maxim that "The good is the enemy of the better", and kept encouraging the engineers to settle for designing a component/system/whatever which was good enough for the job requirement, not perfect.

The particular example they gave was of one unnamed company whose engineers were designing a part which had to pass a humidity test. The engineers got so caught up in the process that they felt the best way to prove they'd be able to pass the humidity test was to make the part survive being immersed in water. However this was proving complex and taking up valuable time, and Shea was startled to discover that in all this design, test and redesign they'd never actually subjected the part to a humidity test...

[smartcooky]

I assume engineers have a way of identifying that point.

We do; it's called a deadline.   

All seriousness aside, no we don't.  In fact, that's one of my interview questions for engineering managers.  It's a trick question in a sense because unqualified candidates think they have a universal answer.  We quip that a project in design engineering has two phases:  too early to tell, and too late to do anything about it.  There is no hard-and-fast point where you markedly shift the approach.  Analysis at the beginning of a project is proven to have the greatest effect on cost and complexity, but it happens before enough of the problem has been explored to really know what to analyze.  It's the manager's job to break the "analysis paralysis" that occurs from trying to reason conclusively with too little data, and then to get the ball rolling.

The "correct" answer to the LM's problem that the plume deflectors were added to solve would have been to take the LM back to its conceptual mechanical design stage and weigh more heavily the jet duty cycle with its thermal effects.  Then the jets could have been positioned to avoid thermal loads on structure over the firing times it became apparent later were wanted for mission planning.  But then you would have had just another set of problems that arose from that systemic arrangement that weren't present in the LM that flew.  The urge to analyze extensively follows the natural urge to find an optimal solution.  In any significant engineering problem there simply does not exist an optimal solution.  The engineer and author Henry Petroski coined the term "satisficing" to address this.  Engineering problem spaces are defined by opposing variables that are always in conflict, always in tension.  A solution for these variables is ever only "good enough."

The hoaxie that drills down, moving the goal posts or outright changing the character of their claim or throwing up all sorts of chaff in an attempt to find wriggle room.

Which they will eventually find, since no engineering survives all conceivable criticism.  But the key is to determine at what level you've found something that merits criticism and how consequential that is to questions like that of authenticity.

In reading this answer, I'm reminded again of Murray & Cox's description of Joe Shea's approach to managing the design of the Apollo and Saturn spacecraft. He used as his maxim that "The good is the enemy of the better", and kept encouraging the engineers to settle for designing a component/system/whatever which was good enough for the job requirement, not perfect.

The particular example they gave was of one unnamed company whose engineers were designing a part which had to pass a humidity test. The engineers got so caught up in the process that they felt the best way to prove they'd be able to pass the humidity test was to make the part survive being immersed in water. However this was proving complex and taking up valuable time, and Shea was startled to discover that in all this design, test and redesign they'd never actually subjected the part to a humidity test...

Yup... if you want to drive from Los Angeles to San Francisco in under 10 hours, you can do it easily in a Ferrari. You can also do it in A Chevy Spark LS. The Ferrari might be better, but the Spark is good, is cheaper to buy and run and easrier to obtain.

[Mag40]

Btw, do you have a copy of that exchange?

I don't, and I understand it's gone entirely from IMDB now.

Jay

Can you remember what year this was, and what section the discussion was in?

Did you use jayutah or some other username?

What username was the blunder using?

I am prepared to have a trawl through some internet archives to see if I can find it, but I would like some kind of starting point.

Here is the dead link -
http://www.imdb.com/title/tt0446557/board/flat/133905495

[JayUtah]

Btw, do you have a copy of that exchange?

I don't, and I understand it's gone entirely from IMDB now.

Jay

Can you remember what year this was, and what section the discussion was in?

Did you use jayutah or some other username?

What username was the blunder using?

I am prepared to have a trawl through some internet archives to see if I can find it, but I would like some kind of starting point.

Here is the dead link -
http://www.imdb.com/title/tt0446557/board/flat/133905495

Good find, thanks.  The only thing I'm sure of is that I did not use JayUtah as my user name for that debate.  I don't remember what I did use.

[Mag40]

Btw, do you have a copy of that exchange?

I don't, and I understand it's gone entirely from IMDB now.

Jay

Can you remember what year this was, and what section the discussion was in?

Did you use jayutah or some other username?

What username was the blunder using?

I am prepared to have a trawl through some internet archives to see if I can find it, but I would like some kind of starting point.

Here is the dead link -
http://www.imdb.com/title/tt0446557/board/flat/133905495

Good find, thanks.  The only thing I'm sure of is that I did not use JayUtah as my user name for that debate.  I don't remember what I did use.

Is this that bingo moment?

Archive -

https://moviechat.org/tt0446557/A-Funny-Thing-Happened-on-the-Way-to-the-Moon#discover

Two large threads -

https://moviechat.org/tt0446557/A-Funny-Thing-Happened-on-the-Way-to-the-Moon/58c7698a6b51e905f686f522/Could-this-be-one-of-the-most-under-appreciated-films-of-its-time

https://moviechat.org/tt0446557/A-Funny-Thing-Happened-on-the-Way-to-the-Moon/58c7698b6b51e905f686f654/I-dont-know-I-just-dont-know


Adding:

https://web.archive.org/web/http://www.imdb.com/title/tt0446557/board