Radiation

[raven]

If you say so....

"If you say so"?! The speed of light is one of those damn basic laws of physics. Ye canna change the laws o' physics! Unless you have an explanation for this, your whole argument is stillborn.
Besides I noticed a problem in the paper you linked already, just reading the abstract . "By only changing the flight duration an assessment for the total dose of a journey to Mars is provided." See, Apollo was something of a roll of the dice. With its short duration, two weeks max, it was unlikely to encounter a potentially dangerous solar event. Not impossible, but a risk they were willing to take for national pride. A Mars mission, on the other hand, would last over a year using current and near-term propulsion tech. Many planned Mars missions have some kind of 'solar storm shelter' to account for this. So its methodology is already flawed, by my reading. I am not nearly so qualified as many of the others here to comment on the rest of the paper, but it seems a pretty damning error right out of the gate.

[timfinch]

I apologize for any offense.  Your immediate response to the article without due process elicited such a response.  I will try to be better in the future.

[JayUtah]

Considering my distinct lack of expertise in the subject matter, I am totally reliant upon the expertise of others...

Yes you are dependent in that way, and your choice of experts to advise you is not encouraging, nor your vetting criteria.  You were quite willing to trust an Australian kid to advise you on astrophysics, but you reject the findings of actual working professionals and call them names.

...but is not not true of us all?

No.  Most of us work in situations where there are serious empirical consequences for error or misconception.  No, you don't get to make the argument that science is necessarily a faith-based exercise.

Consider the article and take from it what you may.

If you consider the author to be a suitably qualified expert and his findings to be robust enough to require explanation from your critics, can you explain why he has -- just one page 1 -- contradicted two suggestions you have made here in this forum?  Do you accept his authority to contradict and correct your misconceptions?  I'm not asking you to assert that he is a qualified expert.  I'm asking you to reconcile the inconsistency between your claims about shielding material with his claims about shielding material, under the presumption arguendo that he is expert.

[timfinch]

If you say so....

"If you say so"?! The speed of light is one of those damn basic laws of physics. Ye canna change the laws o' physics! Unless you have an explanation for this, your whole argument is stillborn.
Besides I noticed a problem in the paper you linked already, just reading the abstract . "By only changing the flight duration an assessment for the total dose of a journey to Mars is provided." See, Apollo was something of a roll of the dice. With its short duration, two weeks max, it was unlikely to encounter a potentially dangerous solar event. Not impossible, but a risk they were willing to take for national pride. A Mars mission, on the other hand, would last over a year using current and near-term propulsion tech. Many planned Mars missions have some kind of 'solar storm shelter' to account for this. So its methodology is already flawed, by my reading. I am not nearly so qualified as many of the others here to comment on the rest of the paper, but it seems a pretty damning error right out of the gate.

When you consider the fact that there was nine manned lunar missions then can you really justify NASA's cavalier approach to the safety of the astronauts?

[timfinch]

Considering my distinct lack of expertise in the subject matter, I am totally reliant upon the expertise of others...

Yes you are dependent in that way, and your choice of experts to advise you is not encouraging, nor your vetting criteria.  You were quite willing to trust an Australian kid to advise you on astrophysics, but you reject the findings of actual working professionals and call them names.

...but is not not true of us all?

No.  Most of us work in situations where there are serious empirical consequences for error or misconception.  No, you don't get to make the argument that science is necessarily a faith-based exercise.

Consider the article and take from it what you may.

If you consider the author to be a suitably qualified expert and his findings to be robust enough to require explanation from your critics, can you explain why he has -- just one page 1 -- contradicted two suggestions you have made here in this forum?  Do you accept his authority to contradict and correct your misconceptions?  I'm not asking you to assert that he is a qualified expert.  I'm asking you to reconcile the inconsistency between your claims about shielding material with his claims about shielding material, under the presumption arguendo that he is expert.

Are you sure you looked at the entire pdf as there is more than a single page?  I claim that the apollo craft had no dedicated shielding and relied on the superstructure, heat shields and onboard equipment to provide shielding.  Nothing he says contradicts anything I have said.

[timfinch]

If the shoe were on the other foot then the approach I would have used would be to acknowledge that the readings are circumspect and probably the result of archaic measurement equipment.  I don't think I would disregard what is an obvious incongruence.  I'm just saying...

[onebigmonkey]

Feel free to disregard any information that doesn't support your hypothesis.  It is the way of religious fanatics isn't it?

You seem to be doing that by not reading what your posted research text says, eg:

The flight path of Apollo 11 avoids the centre of the Van Allen  radiation  belt in  an  elegant  way

[raven]

If you say so....

"If you say so"?! The speed of light is one of those damn basic laws of physics. Ye canna change the laws o' physics! Unless you have an explanation for this, your whole argument is stillborn.
Besides I noticed a problem in the paper you linked already, just reading the abstract . "By only changing the flight duration an assessment for the total dose of a journey to Mars is provided." See, Apollo was something of a roll of the dice. With its short duration, two weeks max, it was unlikely to encounter a potentially dangerous solar event. Not impossible, but a risk they were willing to take for national pride. A Mars mission, on the other hand, would last over a year using current and near-term propulsion tech. Many planned Mars missions have some kind of 'solar storm shelter' to account for this. So its methodology is already flawed, by my reading. I am not nearly so qualified as many of the others here to comment on the rest of the paper, but it seems a pretty damning error right out of the gate.

When you consider the fact that there was nine manned lunar missions then can you really justify NASA's cavalier approach to the safety of the astronauts?

9 rolls of the dice, with separate forecasts to make sure the risks were as low as possible, is quite a bit different than the all in 28 'rolls' for a year long Mars mission, with no chance for a high risk forecast delaying the mission, since they would be already in space.  Besides, whether we would currently justify it by today's standards is  irrelevant to the question of whether it happened or not.

[JayUtah]

Your immediate response to the article without due process elicited such a response.

My immediate response arose out of information I was able to discover immediately, and which bears upon the evidentiary value of the paper.  You proffered this paper, which presents itself as scientific findings.  Due process requires me to evaluate it not just on its facial value, but on foundational factors that would ordinarily transform such findings into evidence.  Foundational factors may be assessed in mere minutes.  Facial factors may be assessed in an hour or so.  A proper methdology vetting would take days.  All those factors matter in determining whether the author's conclusions have the effect you desire.  What can be determined in zero time is to what extent you performed due process before offering this material as evidence.  If you didn't do any, or don't consider yourself qualified to do it, then its value as evidence is not something you can claim to be sure of.  That reduces the importance for others to take on the mantle of vetting it for you.

[JayUtah]

Are you sure you looked at the entire pdf as there is more than a single page?

I have the entire paper.  My point is that, having proceeded no farther than the first page, I already have encountered materials that require your attention.

I claim that the apollo craft had no dedicated shielding...

That is not the claim to which I refer.  When we were discussing the materials used for shielding, you insisted that shielding had to be composed of hydrogen-rich materials.  I pointed out that aluminum was commonly used as a radiation shielding material.  You responded that this was impossible because it would produce secondary radation, presumably in unsustainable amounts.  If you accept this author as an expert, and this author says that aluminum is commonly used as a shielding material, do you concede that you were wrong when you claimed it wasn't, or couldn't be?

Further, you suggested last night and then today that a translunar trajectory would have to pass through the Van Allen belts.  You pooh-poohed depictions of the orbital geometry as having been "drawn in crayon for children."  Yet your author here agrees that there was an "elegant" way of flying the trajectory that avoided all but the fringes of the trapped radiation.  If you accept this author as an expert, do you concede that your dismissal of Apollo trajectories was premature and not properly informed?

[bknight]

Gentlemen, I provide this in-depth analysis of radiation exposure for your consideration.  It is interesting to note that the author indicates the only way the math works is to remove all contributions from solar radiation.  Take your time and embrace the consequences of this revelation.

https://www.researchgate.net/publication/322643901_Radiation_Analysis_for_Moon_and_Mars_Missions

From his conclusions.

The flight path of Apollo voids the centre of the Van Allen radiation in an elegant way.  It's a pity that this skillful trajectory has no been highlighted by NASA.Fr a better avoidance one would have to fly first a polar parking orbit and then turn off in the direction Moon--or Mars.  But this would cost much more energy.

Even you un-reviewed author detects that Apollo missed the most dense portions of the VARB, why can't you?

[bknight]

If you say so....

"If you say so"?! The speed of light is one of those damn basic laws of physics. Ye canna change the laws o' physics! Unless you have an explanation for this, your whole argument is stillborn.
Besides I noticed a problem in the paper you linked already, just reading the abstract . "By only changing the flight duration an assessment for the total dose of a journey to Mars is provided." See, Apollo was something of a roll of the dice. With its short duration, two weeks max, it was unlikely to encounter a potentially dangerous solar event. Not impossible, but a risk they were willing to take for national pride. A Mars mission, on the other hand, would last over a year using current and near-term propulsion tech. Many planned Mars missions have some kind of 'solar storm shelter' to account for this. So its methodology is already flawed, by my reading. I am not nearly so qualified as many of the others here to comment on the rest of the paper, but it seems a pretty damning error right out of the gate.

When you consider the fact that there was nine manned lunar missions then can you really justify NASA's cavalier approach to the safety of the astronauts?

They choose a program that had defined risks, but those risks were small enough, although not zero to proceed.

[MBDK]

Mr. Finch, your entire argument (concerning a discrepancy between the Apollo missions' exposures and the data observed by MSL/RAD in transit to Mars) is ignorant of this statement (from your own reference's abstract):

"The predicted dose equivalent rate during solar maximum conditions could be as low as one-fourth of the current RAD cruise measurement. However, future measurements during solar maximum and minimum periods are essential to validate our estimations."

Why is this relevant?  From - https://www.lpi.usra.edu/meetings/leag2012/pdf/3019.pdf

"The Apollo missions were the only ones to fly during a solar maximum (from the peak through the declining phase)."

Even a Nuclear Electrician should be able to connect the dots, now.  (I am just funnin' you a little, as I was a Physical Science Technician, a.k.a. Radcon Tech, for over 32 years in the Civil Service and had to deal with you squids almost daily).  I actually do hope this helps you understand the validity of the dose measurements.  And the ignorant comment is true, as we are ALL ignorant of some things, even me (just ask my friends).  Good luck.

I don't want to be the one to burst your bubble but as GCR is inversely proportion to solar activity SPE's are directly proportional and the threat to personnel increases.

You can't burst what doesn't exist.  However, I would like to know why you think it is at all reasonable for you to reference an article (https://arxiv.org/pdf/1503.06631.pdf) for the data you argue supports your position, yet disavow it when it specifically conflicts with your faulty conclusions?  You have been busted for entering the CSCA without anti-c's and erroneously claim the posting was invalid.  Report to Captain's Mast.

[mako88sb]

If you say so....

"If you say so"?! The speed of light is one of those damn basic laws of physics. Ye canna change the laws o' physics! Unless you have an explanation for this, your whole argument is stillborn.
Besides I noticed a problem in the paper you linked already, just reading the abstract . "By only changing the flight duration an assessment for the total dose of a journey to Mars is provided." See, Apollo was something of a roll of the dice. With its short duration, two weeks max, it was unlikely to encounter a potentially dangerous solar event. Not impossible, but a risk they were willing to take for national pride. A Mars mission, on the other hand, would last over a year using current and near-term propulsion tech. Many planned Mars missions have some kind of 'solar storm shelter' to account for this. So its methodology is already flawed, by my reading. I am not nearly so qualified as many of the others here to comment on the rest of the paper, but it seems a pretty damning error right out of the gate.

When you consider the fact that there was nine manned lunar missions then can you really justify NASA's cavalier approach to the safety of the astronauts?

Hardly cavalier since it's already been mentioned that they were able to predict solar flares with about a weeks worth of warning. If one did happen to occur while a mission was in progress, they had contingency plans ready to attempt to minimize the additional radiation exposure as much as possible which of course, the degree of success or failure would depend on when during a mission an event occurred. It was always known that there was potential for an event that could cause the death of the entire crew in space but they did everything they could to minimize the possibility of it happening. As already mentioned, the astronauts were all former test pilots. Most were also naval aviators who risked their lives landing on aircraft carriers. They knew exactly what they were getting into and accepted the risks involved.

[JayUtah]

The paper is riddled with conceptual errors, errors in method, simplifying assumptions, and assumptions made in lieu of data.  An example of conceptual error:  that SPEs cannot be predicted.  Example of error in method:  simplistic manipulation of trapped radiation model solver.  Examples of simplifying assumptions:  one-body model of translunar trajectory; quiescent Sun contribution is negligible; VA radiation level is constant.  Example of assumptions made in lieu of data:  shielding factors of Apollo structure, mission success estimates.  These errors make his findings in the form of dosage estimates essentially worthless.  Notably absent also is any sort of error analysis, which must be present in any rationale that relies heavily on estimates made in lieu of data.  The error analysis would have helped the author determine the degree to which his final numbers could vary.  Also, it's not accurate to say that the only way the author could get the numbers to work was to eliminate the Sun.  It's more accurate to say he assumed the contribution of a quiescent Sun would be negligible compared to other factors he was going to consider.  That's arguably another error.