Radiation

[JayUtah]

That didn't hurt did it?  I did not intend that it should...

Please explain this comment.

[timfinch]

Cosmic Rays

Cosmic ray fluxes, consisting of completely ionized atomic nuclei originating outside the solar system and accelerated to very high energies, provided average dose rates of 1.0 millirads per hour in cislunar space** and 0.6 millirads per hour on the lunar surface. These values are expected to double at the low point in the 11-year cycle of solar-flare activity (solar minimum) because of decreased solar magnetic shielding of the central planets. The effect of high-energy cosmic rays on humans is unknown but is considered by most authorities not to be of serious concern for exposures of less than a few years. Experimental evidence of the effects of these radiations is dependent on the development of highly advanced particle accelerators or the advent of long-term manned missions outside the Earth's geomagnetic influence.

Source:  https://history.nasa.gov/SP-368/s2ch3.htm

This is not the whole story.

Again, you show that you don't understand the physics, and in particular you don't understand why a particular measured dose to an UNPROTECTED body differs from that which might be suffered by a shielded body


The cosmic ray spectrum clearly shows that the number of cosmic rays (the cosmic ray flux) detected drops off dramatically as we go to higher energies. The spectrum exhibits a ‘knee’ and an ‘ankle’, both of which deviate from the standard exponential decline (blue line).

The range of energies encompassed by cosmic rays is truly enormous, starting at about 107 eV and reaching 1020 eV for the most energetic cosmic ray ever detected. By plotting this range of energies against the number of cosmic rays detected at each energy we generate a cosmic ray spectrum which clearly shows that the number of cosmic rays drop off dramatically as we go to higher energies.

Roughly speaking, for every 10% increase in energy beyond 109 eV, the number of cosmic rays per unit area falls by a factor of 1,000. However, if we look at the spectrum more closely we can see a knee at ~ 1015 eV and an ankle at ~ 1018 eV.

http://astronomy.swin.edu.au/cosmos/C/Cosmic+Ray+Energies

Let me try to put this is layman's terms for you., since you seem to not understand

Imagine that you have to go into an area (in order to perform some task) where there are 10,000 people shooting with shotguns from some distance; not close enough to blow a hole in you, but far enough away so that you will be constantly showered with pellets. However, in among those shooters are a some people armed with .22 cal rifles each firing one round per minute, a couple with a 7.62 mm rifle who will shoot once every 10 minutes, and finally a shooter armed with a 20mm cannon, who will be firing once per hour.. None of these shooters are actually aiming at you, but they are shooting in the general direction of where you are going to be.

What these shooters will be firing at you represents a spectrum of missiles.... at the less dangerous end of the spectrum are the shotgun pellets, huge numbers and frequency, and at the more dangerous end, the 20mm cannon;  far more dangerous but far less frequent.

If you go in unprotected, the shotgun pellets will do you serious damage
If you wear minimal protection, say, heavy leather coveralls, they will protect you from the shotgun pellets but not from anything else
If you wear a lightweight bullet proof vest, it will protect you from the pellets and the 22 cal.
If you go for full Kevlar body armour, that will protect you from everything except the 20mm cannon.
If you wear a suit made of one inch armour plate, it will protect you from the 20mm cannon.

You may choose the full protection, but that is going to compromise your ability to carry out whatever task you need to carry out.

The Apollo missions (and indeed all space missions) are designed and built such that shielding is incorporated into design. This protects the spacecraft (and its occupants) from the vast majority of the radiation (the shotgun pellets, and possibly, the .22 cal). The exposure to the higher end particles (the 7.62 and the 20mm cannon) is the risk they take, but even then, there are procedures put in place to use the existing shielding to help with protection, such as, in the case of a CME, orienting the spacecraft to put the maximum amount of its mass between the crew and the Sun. (not sure of the was a plan on Apollo, I'll leave other more knowledgeable people to answer that)     

You do understand the difference between radiation flux and equivalent biological damage don't you?

[timfinch]

That didn't hurt did it?  I did not intend that it should...

Please explain this comment.

Refer to my previous post.  I was asking if the information found in it was painful for you to accept.

[JayUtah]

Refer to my previous post.  I was asking if the information found in it was painful for you to accept.

You're being very smug.  Is your primary intent here to inflict distress on your critics, or to understand the factors that affect the validity of your claims?  You seem to have a very inflated opinion of the strength of your interpretations and research methods.  That's not an especially convincing position, given that everyone else who knows this material well disagrees with your interpretation of it.

[bknight]

...
You are not paying attention.  a radiation level of .47 mgy/day is not lethal and a 10 mission in such a background is well within the established safe limits.  I contend not that the mission itself would not be feasible, I contend because you could not guarantee that the mission would not encounter an SPE then it would be Russian Roulette.  My point is that mission dose for a lunar transits should as a minimum be at least .47 mgy/day.
[/quote]

I was pointing to the ultimate conclusion of radiation effects.  Your point is that you need to prove that the published data are in correct and "It doesn't look right to me" isn't sufficient.

[timfinch]

So let's recap.  Cislunar space is radioactive and the moon is 30% more radioactive than cis lunar space.  Assuming any transit through the VAB is indeed higher that cislunar space and the moon then it is logical that any lunar mission would have to have a higher dose rate than cislunar space.  Can anyone find something wrong with this logic?

[timfinch]

...
You are not paying attention.  a radiation level of .47 mgy/day is not lethal and a 10 mission in such a background is well within the established safe limits.  I contend not that the mission itself would not be feasible, I contend because you could not guarantee that the mission would not encounter an SPE then it would be Russian Roulette.  My point is that mission dose for a lunar transits should as a minimum be at least .47 mgy/day.

I was pointing to the ultimate conclusion of radiation effects.  Your point is that you need to prove that the published data are in correct and "It doesn't look right to me" isn't sufficient.
[/quote]

I am not sure I understand you.  Do you want me to prove published data is correct?

[bknight]

Remember, I am not claiming the reported doses are deadly.  I am claiming the reported doses do not reflect expected radiation levels for cislunar operations.

And the point you're being challenged on is "expected radiation levels." Your expectation is based on a series of simplistic assumptions in interpreting the data.

I can read and understand, what you are incapable of doing so far is to show where the radiation data you posted early in the discussion is inaccurate.  You still don't it and I suspect you never will as you are convinced of your analysis is correct when in fact you don not have the knowledge to prove it other than "it doesn't match" which won't be acceptable to the audience.

tim you should really look at all the alternatives and by your posts you have not.  In fact I suspect you will not accept the possibility that you are the one who is wrong, not the rest off us.

I posted a thought that fits you to a T, I'm right all the rest of you are wrong.  Sorry it rarely works that way in real life, but then you live in the HB atmosphere.

You need to prove your  "expected radiation levels." are correct by analysis not just looking at them and concluding "the radiation values posted by NASA are incorrect.

My assumptions are based on empirical data obtained in 2012 by the MSL/RAD detectors aboard the Mars probe.  It is also supported by the the CraTer radiation monitoring of the moon.

ETA-- my commentary that didn't attached to my quote.

Your assumptions that the data collected recently makes the previous data published from the Apollo mission is too low, that is what you need to prove, and not by visual inspections of the numbers.  You need to be able to show the audience how you calculate  visual comparisons of the values will not suffice.  You're wrong but are to enamored of your ideas to accept anything else.  "I'm right the rest of you are wrong"

[timfinch]

Refer to my previous post.  I was asking if the information found in it was painful for you to accept.

You're being very smug.  Is your primary intent here to inflict distress on your critics, or to understand the factors that affect the validity of your claims?  You seem to have a very inflated opinion of the strength of your interpretations and research methods.  That's not an especially convincing position, given that everyone else who knows this material well disagrees with your interpretation of it.

You are right.  It was very unprofessional of me.  I apologize.  I will contain myself in the future.

[JayUtah]

So let's recap.  Cislunar space is radioactive and the moon is 30% more radioactive than cis lunar space.  Assuming any transit through the VAB is indeed higher that cislunar space and the moon then it is logical that any lunar mission would have to have a higher dose rate than cislunar space.  Can anyone find something wrong with this logic?

No, the species of particle matters in your analysis. You're trying to reduce this to pure scalar values. The secondary radiation from the Moon cannot be lumped together with GCR.

[timfinch]

Remember, I am not claiming the reported doses are deadly.  I am claiming the reported doses do not reflect expected radiation levels for cislunar operations.

And the point you're being challenged on is "expected radiation levels." Your expectation is based on a series of simplistic assumptions in interpreting the data.

I can read and understand, what you are incapable of doing so far is to show where the radiation data you posted early in the discussion is inaccurate.  You still don't it and I suspect you never will as you are convinced of your analysis is correct when in fact you don not have the knowledge to prove it other than "it doesn't match" which won't be acceptable to the audience.

tim you should really look at all the alternatives and by your posts you have not.  In fact I suspect you will not accept the possibility that you are the one who is wrong, not the rest off us.

I posted a thought that fits you to a T, I'm right all the rest of you are wrong.  Sorry it rarely works that way in real life, but then you live in the HB atmosphere.

You need to prove your  "expected radiation levels." are correct by analysis not just looking at them and concluding "the radiation values posted by NASA are incorrect.

My assumptions are based on empirical data obtained in 2012 by the MSL/RAD detectors aboard the Mars probe.  It is also supported by the the CraTer radiation monitoring of the moon.

My methodology is sound.  If a thing can't be then it isn't.  Without actually conducting actual radiation testing in cislunar, lunar and VAB environment then I must rely on the availability of previous test information.  I simply observe the limits of the available information and made a logical deduction.  If there is an error in my logic point it out and I will address it.

[timfinch]

So let's recap.  Cislunar space is radioactive and the moon is 30% more radioactive than cis lunar space.  Assuming any transit through the VAB is indeed higher that cislunar space and the moon then it is logical that any lunar mission would have to have a higher dose rate than cislunar space.  Can anyone find something wrong with this logic?

No, the species of particle matters in your analysis. You're trying to reduce this to pure scalar values. The secondary radiation from the Moon cannot be lumped together with GCR.

I will post this again for clarification:  Measurements taken by NASA's Lunar Reconnaissance Orbiter show that the number of high energy particles streaming in from space did not tail off closer to the moon's surface, as would be expected with the body of the moon blocking half the sky.

Rather, the cosmic rays created a secondary — and potentially more dangerous -- shower by blasting particles in the lunar soil which then become radioactive.

"The moon is a source of radiation," said Boston University researcher Harlan Spence, the lead scientist for LRO's cosmic ray telescope. "This was a bit unexpected."

While the moon blocks galactic cosmic rays to some extent, the hazards posed by the secondary radiation showers counter the shielding effects, Spence said at a press conference at the American Geophysical Union meeting in San Francisco this week.

Overall, future lunar travelers face a radiation dose 30 percent to 40 percent higher than originally expected, Spence said.

[JayUtah]

Remember, I am not claiming the reported doses are deadly.  I am claiming the reported doses do not reflect expected radiation levels for cislunar operations.

And the point you're being challenged on is "expected radiation levels." Your expectation is based on a series of simplistic assumptions in interpreting the data.

I can read and understand, what you are incapable of doing so far is to show where the radiation data you posted early in the discussion is inaccurate.  You still don't it and I suspect you never will as you are convinced of your analysis is correct when in fact you don not have the knowledge to prove it other than "it doesn't match" which won't be acceptable to the audience.

tim you should really look at all the alternatives and by your posts you have not.  In fact I suspect you will not accept the possibility that you are the one who is wrong, not the rest off us.

I posted a thought that fits you to a T, I'm right all the rest of you are wrong.  Sorry it rarely works that way in real life, but then you live in the HB atmosphere.

You need to prove your  "expected radiation levels." are correct by analysis not just looking at them and concluding "the radiation values posted by NASA are incorrect.

My assumptions are based on empirical data obtained in 2012 by the MSL/RAD detectors aboard the Mars probe.  It is also supported by the the CraTer radiation monitoring of the moon.

My methodology is sound.  If a thing can't be then it isn't.  Without actually conducting actual radiation testing in cislunar, lunar and VAB environment then I must rely on the availability of previous test information.  I simply observe the limits of the available information and made a logical deduction.  If there is an error in my logic point it out and I will address it.

Your haven't shown that it's sound. Absent information that would directly support your case, your inferring it from what you have.  Your inferences are simplistic.

[timfinch]

Akeem's Razor?

[JayUtah]

So let's recap.  Cislunar space is radioactive and the moon is 30% more radioactive than cis lunar space.  Assuming any transit through the VAB is indeed higher that cislunar space and the moon then it is logical that any lunar mission would have to have a higher dose rate than cislunar space.  Can anyone find something wrong with this logic?

No, the species of particle matters in your analysis. You're trying to reduce this to pure scalar values. The secondary radiation from the Moon cannot be lumped together with GCR.

I will post this again for clarification:  Measurements taken by NASA's Lunar Reconnaissance Orbiter show that the number of high energy particles streaming in from space did not tail off closer to the moon's surface, as would be expected with the body of the moon blocking half the sky.

Rather, the cosmic rays created a secondary — and potentially more dangerous -- shower by blasting particles in the lunar soil which then become radioactive.

"The moon is a source of radiation," said Boston University researcher Harlan Spence, the lead scientist for LRO's cosmic ray telescope. "This was a bit unexpected."

While the moon blocks galactic cosmic rays to some extent, the hazards posed by the secondary radiation showers counter the shielding effects, Spence said at a press conference at the American Geophysical Union meeting in San Francisco this week.

Overall, future lunar travelers face a radiation dose 30 percent to 40 percent higher than originally expected, Spence said.

You didn't address my post. You just quoted it and repeated your claim. I'm explaining that your interpretation of this material makes simplifying assumptions that render it invalid. If the detector is behind substantial structure as opposed to freely exposed, it will differentiate between primary and secondary radiation.