Author Topic: Radiation  (Read 616527 times)

Offline JayUtah

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Re: Radiation
« Reply #105 on: March 24, 2018, 11:57:24 PM »
In summary...

Yes, that's what a typical high schooler would learn about GCR.  What's your point?  Nothing in there says Apollo was improperly protected.
"Facts are stubborn things." --John Adams

Offline JayUtah

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Re: Radiation
« Reply #106 on: March 24, 2018, 11:59:19 PM »
Even lightweight aluminum is useful as shielding.

The preferred material, in fact, in spacecraft.  The design manuals express shielding design in terms of aluminum-equivalent provisions.
"Facts are stubborn things." --John Adams

Offline timfinch

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Re: Radiation
« Reply #107 on: March 25, 2018, 12:00:32 AM »
I have provided multiple reference that state that the high energy protons require hydrogenous shielding to attenuate it and that acceptable masses range from 25 g/cm2 to 80 g/cm2.  The Apollo crafts had no hydrogenous shielding of any kind.  I have demonstrated that empirical data from the Mars/Rad radiation survey of the transit to Mars indicates a background radiation level of roughly 470 mgy/day.  It is obvious to the casual observer that cislunar space as it is outside the shielding of the earth's magnetic field share the same baseline GCR level.  It goes without saying that any apollo craft traveling across cislunar space would be exposed to this GCR baseline radiation level as it had no shielding capable of attenuating the high energy protons of GCR.  It is demonstrably proving that all lunar missions cannot have a dose rate of less than GCR background level.  The defense rest.

Offline timfinch

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Re: Radiation
« Reply #108 on: March 25, 2018, 12:02:06 AM »
Even lightweight aluminum is useful as shielding.

The preferred material, in fact, in spacecraft.  The design manuals express shielding design in terms of aluminum-equivalent provisions.

Aluminum is useless in shielding GCR's and in fact increase biological dosing due to secondary emissions from the high energy protons.

Offline JayUtah

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Re: Radiation
« Reply #109 on: March 25, 2018, 12:11:25 AM »
Aluminum is useless in shielding GCR's and in fact increase biological dosing due to secondary emissions from the high energy protons.

At what thicknesses?  For what energies and fluxes?

I asked you earlier what is your experience in spacecraft design, either manned or unmanned.  Why haven't you answered that question?  Will you please answer it now?
"Facts are stubborn things." --John Adams

Offline timfinch

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Re: Radiation
« Reply #110 on: March 25, 2018, 12:13:55 AM »
This isn't about me.  You don't have to be a mechanic to know something is wrong with your car.  I can read and I can see.  Take a moment to review the data and embrace the issue.  Intellectual cowardice is so unappealing.

Offline JayUtah

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Re: Radiation
« Reply #111 on: March 25, 2018, 12:17:36 AM »
I have provided multiple reference that state that the high energy protons require hydrogenous shielding to attenuate it...

That is the optimal material for shielding.  Is the optimal material always the material that's used?

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...and that acceptable masses range from 25 g/cm2 to 80 g/cm2.

Acceptable for what mission?  What duration?  During solar minimum or solar maximum?  You found data that show the behavior of those shielding factors.  Why did you draw the separate conclusion that those are the recommended factors?

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The Apollo crafts had no hydrogenous shielding of any kind.

The Apollo spacecraft did not include components specifically designated as radiation shielding.  This was because an acceptable degree of shielding was provided by the structure of the spacecraft itself.  While not part of the structure, the interstitial padding in the command module qualifies as low-atomic-number material.  Did you factor that into your analysis?

Your claim seems to be that since the Apollo spacecraft weren't designed the way you think they should have been designed, they were not viable spacecraft.  That claim requires you to be able to demonstrate some expertise in spacecraft design that goes above quoting offhand educational materials that just happen to be hosted at NASA.

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The defense rest.

"My conclusion is obvious" is not a case.  Your argument would ordinarily require an analysis that goes deeper than just a few cursory comparisons.  I've alluded to some of the factors that would be considered in such an analysis.  They don't seem to interest you.
"Facts are stubborn things." --John Adams

Offline bknight

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Re: Radiation
« Reply #112 on: March 25, 2018, 12:17:56 AM »
The only claim I make is the radiation exposure of the Apollo lunar missions do not coincide with expected values using empirical data from the 21st century.  That is the extent of my claim.

You do realize that the data of the Mars mission was determined with little radiation protection whereas the Apollo capsule were layered with low density material and stainless steel.  Both are good insulators to radiation so the rates should be lower than those derived by Curiosity mission.

In a word, No.  You should recheck your notes on this as I believe you are completely wrong.
Cite where the detection panels were in cased with attenuation.

the potential radiation hazard for astronauts
(Zeitlin et al. 2013). Because of the shielding of the spacecraft
and internal structures, RAD measured a mix of primary and
secondary particles. The latter are produced by primary particles
via nuclear or electromagnetic interactions as they traverse the
spacecraft. A simplified shielding model of the spacecraft developed
at JPL has been be used to calculate the shielding distribution
as seen by RAD, which is mounted to the top deck of the
rover (Zeitlin et al. 2013). Shielding around the RAD instrument
during cruise was complex: most of the solid angle was lightly
shielded with a column density smaller than 10 g/cm2
, while the
rest was broadly distributed over a range of depths up to about
100 g/cm2
https://arxiv.org/pdf/1503.06631.pdf

Alright but the shielding/construction was not as complete as Apollo.  Again there were layers in the Apollo command module.

It is doubtful that such construction was used in the Curiosity mission.

You asked what was my point in the next post.  The point being that the construction was more than ample to protect the crew, as have all missions.  Your next task will be to state how you determined the rate was low other than "it looks low to me".

Further, your research should have led you to the answer why A14 mission radiation was higher than the rest of the mission, but your posts don't indicate you know.  One of the dosimeters of the crew broke and Alan and Ed' badges were used for the mission reports.  Nothing to due with SPM just arithmetic.
« Last Edit: March 25, 2018, 12:44:18 AM by bknight »
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
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Offline timfinch

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Re: Radiation
« Reply #113 on: March 25, 2018, 12:24:58 AM »
I will say this slowly.  The Apollo had nothing on it or in it that could attenuate GCR radiation.  NASA understood this but relied on the fact that the mission was not long enough that it would pose a health hazard.  I don't question that logic.  The point I make is that because it is a given then by definition it sets a baseline exposure rate that isn't reflected in the apollo data.  The only plausible reason is that they remained in LEO.  If you have a better idea I am more that willing to listen.

Offline JayUtah

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Re: Radiation
« Reply #114 on: March 25, 2018, 12:27:21 AM »
This isn't about me.

As long as your argument is based on your interpretation of technical data, your qualifications to do so remain relevant.  They are, in fact, the only thing that's relevant in an argument based on judgment.  You seem to be suggesting that the Apollo spacecraft were improperly designed.  That judgment carries weight only when the person making it has expertise in spacecraft design.  Asking about that expertise is not "making it about the person."  It's addressing the argument on the proffered grounds.

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You don't have to be a mechanic to know something is wrong with your car.

Do you have to be a trained nuclear technician to operate a nuclear propulsion plant?  Or is there an 18-month training course you have to pass before they let you anywhere near one?  You're suggesting astrophysics and space engineering is comparable to consumer automotive engineering, much of which is intended to be user-serviceable.

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I can read and I can see.

Are you claiming astrophysics, space medicine, and space engineering are nothing more than ordinary layman's common sense?  At first you claimed your experience as a Navy nuclear technician qualified you to draw these conclusions.  That implied -- correctly -- that expertise was required.  Now you seem to be claiming that no expertise is necessary to evaluate spacecraft designs.  You seem to change your mind on what's required based on what you think you can convince people you have.

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Take a moment to review the data and embrace the issue.  Intellectual cowardice is so unappealing.

So is bluster.
"Facts are stubborn things." --John Adams

Offline timfinch

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Re: Radiation
« Reply #115 on: March 25, 2018, 12:31:59 AM »
You have nothing.  You are incapable of contesting any of the salient points and you waste time attacking my credentials.  Demonstrate a level of understanding by showing why my points are invalid.  I am reasonable.  Give me something to work with and I can change my mind.

Offline JayUtah

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Re: Radiation
« Reply #116 on: March 25, 2018, 12:35:39 AM »
I will say this slowly.

Please don't patronize your critics.  They have been very patient with you.

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The Apollo had nothing on it or in it that could attenuate GCR radiation.

It's already been pointed out to you that this declaration is based on a number of misconceptions.  The first is that there is nothing in the CM design that is specifically designated as radiation shielding, and nothing that matches the material description of the optimum form of shielding.  Another is that you misread abstractly formulated data as if they were specific design recommendations.  Yet another is the actual threat GCR posed.

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...then by definition it sets a baseline exposure rate that isn't reflected in the apollo data.

No, you haven't convinced anyone that you're not comparing apples and oranges.  You just assume that there should be congruence in the data sets to within some arbitrarily chosen limit.  That just begs the question.

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The only plausible reason is that they remained in LEO.  If you have a better idea I am more that willing to listen.

The better idea is that you don't know what you're talking about and are drawing simplistic conclusions based on only a cursory understanding.  As for the CSM staying in LEO, do you realize that they would then be a naked-eye object much as is the ISS?  It would also be nearly impossible to have extended radio communications with the spacecraft.  When you say it's the only plausible explanation, it's because you haven't thought through all the problems associated with it.
"Facts are stubborn things." --John Adams

Offline timfinch

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Re: Radiation
« Reply #117 on: March 25, 2018, 12:36:03 AM »
This isn't about me.

As long as your argument is based on your interpretation of technical data, your qualifications to do so remain relevant.  They are, in fact, the only thing that's relevant in an argument based on judgment.  You seem to be suggesting that the Apollo spacecraft were improperly designed.  That judgment carries weight only when the person making it has expertise in spacecraft design.  Asking about that expertise is not "making it about the person."  It's addressing the argument on the proffered grounds.

Quote
You don't have to be a mechanic to know something is wrong with your car.

Do you have to be a trained nuclear technician to operate a nuclear propulsion plant?  Or is there an 18-month training course you have to pass before they let you anywhere near one?  You're suggesting astrophysics and space engineering is comparable to consumer automotive engineering, much of which is intended to be user-serviceable.

Quote
I can read and I can see.

Are you claiming astrophysics, space medicine, and space engineering are nothing more than ordinary layman's common sense?  At first you claimed your experience as a Navy nuclear technician qualified you to draw these conclusions.  That implied -- correctly -- that expertise was required.  Now you seem to be claiming that no expertise is necessary to evaluate spacecraft designs.  You seem to change your mind on what's required based on what you think you can convince people you have.

Quote
Take a moment to review the data and embrace the issue.  Intellectual cowardice is so unappealing.

So is bluster.

It doesn't take a rocket scientist to determine that a rocket doesn't work.  The buildings and ground crew can make that determination during the cleanup.

Offline timfinch

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Re: Radiation
« Reply #118 on: March 25, 2018, 12:38:39 AM »
I will say this slowly.

Please don't patronize your critics.  They have been very patient with you.

Quote
The Apollo had nothing on it or in it that could attenuate GCR radiation.

It's already been pointed out to you that this declaration is based on a number of misconceptions.  The first is that there is nothing in the CM design that is specifically designated as radiation shielding, and nothing that matches the material description of the optimum form of shielding.  Another is that you misread abstractly formulated data as if they were specific design recommendations.  Yet another is the actual threat GCR posed.

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...then by definition it sets a baseline exposure rate that isn't reflected in the apollo data.

No, you haven't convinced anyone that you're not comparing apples and oranges.  You just assume that there should be congruence in the data sets to within some arbitrarily chosen limit.  That just begs the question.

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The only plausible reason is that they remained in LEO.  If you have a better idea I am more that willing to listen.

The better idea is that you don't know what you're talking about and are drawing simplistic conclusions based on only a cursory understanding.  As for the CSM staying in LEO, do you realize that they would then be a naked-eye object much as is the ISS?  It would also be nearly impossible to have extended radio communications with the spacecraft.  When you say it's the only plausible explanation, it's because you haven't thought through all the problems associated with it.

What have you got?  Refute any point with documentation.  I'm waiting...

Offline JayUtah

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Re: Radiation
« Reply #119 on: March 25, 2018, 12:40:24 AM »
You are incapable of contesting any of the salient points...

I've been asking you questions designed to demonstrate the actual scientific principles at work.  You won't answer any of them and insist on this sort of bluster.

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...and you waste time attacking my credentials.

As long as your argument consists of nothing but measuring the facts against your expectations, the basis of those expectations remains a valid point of rebuttal.  You are leveling the sorts of judgments that would be evidentiary only if made from a position of expertise.  It does you no good to wish that the problem with your argument were something else.

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Demonstrate a level of understanding by showing why my points are invalid.

Your points are invalid because they are entirely based on judgment you've conceded you're not qualified to give.  Attempts to show you specific deficiencies in your understanding are met only with emotional outbursts, bluster, and attempts to shift the burden of proof.

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Give me something to work with and I can change my mind.

Several people have tried reasoning Socratically with you, asking you questions designed to challenge your preconceptions and assumptions.  You are unwilling to relax any of them.
"Facts are stubborn things." --John Adams