Radiation

[AtomicDog]

If you say so....

Lord, I hate passive-aggressive  non-denials.

[MBDK]

mako88sb, it never fails to entertain me when hoax/conspiracy proponents argue that the risk was unacceptable, as this speaks volumes regarding their own fortitude.  Men of honor, courage and dedication will do extraordinary things, notably under extraordinary circumstances.  Because of my unique qualifications and knowledge as a Physical Science Technician, when the Fukishima accident occurred, radiological control personnel were needed to assist in the relief and recovery efforts being made.  Prior to knowing how bad things were going to progress (I am happy to say that things had already reached their apex, but no one knew that at the time), I volunteered to go, while others admittedly were afraid to.  I did what I felt needed to be done, and I am still not worthy to carry the jock strap of the Apollo (and many other) astronauts.

[smartcooky]

So you don't think they could have relayed transmission through the unmanned craft.  They were not that smart?

They simply could not have got away with it. Too many people, many of them foreigners (not Americans) at the DSN tracking stations, would have known about it. Technicians are not stupid, they set up, tested and tracked every feed; voice & telemetry. A voice feed of lunar surface operations being uplinked (especially one without quindar tones) would have stood out like Dolly Parton on a fashion show catwalk.

[timfinch]

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?

The author speaks of shielding electron radiation in the VAB,  Electrons can be attenuated by aluminum.  The high energy Proton flux of GCR's is not shielded by aluminum and the damage is increased due to secondary emissions.  I contend the path of the TLI is the determining factor and it is a fortuitous consequence that this path takes an oblique angle through the VAB.  Fuel was the determining factor.  I stand by my statements.

[timfinch]

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?

If you recall the heart of my argument had nothing to do with the radiation of the VAB rather the ever present GCR radiation that should establish a minimum exposure rate for all lunar missions.  The fact that only one of the nine missions had sufficiently high enough mission doses to validate a transit beyond ELO is the point I defend.

[smartcooky]

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.

You see timfinch... this is is what happens when you offer "evidence" without checking its accuracy and veracity... that evidence can be demolished by someone who actually has real expertise.

It must be discouraging to post a link to evidence you think will support you, only to find that others actually DO read what you posted and then point out the link contains statements that directly contradict your position.

It must be really frustrating for the uninformed to have to argue about astrophysics, aerospace engineering and rocket science with actual astrophysicists, aerospace engineers and rocket scientists. This is why HBs don't survive here for very long... its hard for them make headway against actual expertise... the uninformed get found out very, very quickly..   

[smartcooky]

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?

If you recall the heart of my argument had nothing to do with the radiation of the VAB rather the ever present GCR radiation that should establish a minimum exposure rate for all lunar missions.  The fact that only one of the nine missions had sufficiently high enough mission doses to validate a transit beyond ELO is the point I defend.

A fringe reset without the fringe!

[JayUtah]

The author speaks of shielding electron radiation in the VAB,  Electrons can be attenuated by aluminum.

That's the context in which we discussed what materials to use as shielding.  It was a general discussion.  Most missions I have worked with both traverse the Van Allen belts and spend considerable time in cislunar space bombarded by GCR and other sources of radiation.  Aluminum is still the material of choice whether you choose to acknowledge your error or not.

I contend the path of the TLI is the determining factor and it is a fortuitous consequence that this path takes an oblique angle through the VAB.

It wasn't "fortuitous."  It was planned that way.  Dr. James Van Allen himself helped plan the trajectories specifically with the goal of minimizing exposure to trapped radiation.  You spent several hours trying to fumble and bluff your way through a discussion of orbital maneuvers, and you still seem to think you got away with it.

Fuel was the determining factor.

Fuel is one of several factors that affect mission planning, and it did not materially limit which translunar trajectories could be attained, especially with the hybrid trajectory (which you still have not addressed).  Desired landing site, relative positions of Moon, Earth, and Sun, solar weather are other factors in mission planning.

I stand by my statements.

Your statements have been shown to be naive and simplistic, especially on the subject lately of orbital mechanics.  Not unexpected for someone who admits he has no appropriate qualifications, training, or experience.  Again, the reader must decide who is most likely right on the subject of astrophysics and astrodynamics -- tens of thousands of trained, experienced, and knowledgeable professionals, or an electrician named Tim.

[timfinch]

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.

You see timfinch... this is is what happens when you offer "evidence" without checking its accuracy and veracity... that evidence can be demolished by someone who actually has real expertise.

It must be discouraging to post a link to evidence you think will support you, only to find that others actually DO read what you posted and then point out the link contains statements that directly contradict your position.

It must be really frustrating for the uninformed to have to argue about astrophysics, aerospace engineering and rocket science with actual astrophysicists, aerospace engineers and rocket scientists. This is why HBs don't survive here for very long... its hard for them make headway against actual expertise... the uninformed get found out very, very quickly..

So am I to understand you believe the technology exist to predict SPE's to the point to provide a safety margin for lunar missions and that his technology existed during the apollo lunar missions?

[timfinch]

The author speaks of shielding electron radiation in the VAB,  Electrons can be attenuated by aluminum.

That's the context in which we discussed what materials to use as shielding.  It was a general discussion.  Most missions I have worked with both traverse the Van Allen belts and spend considerable time in cislunar space bombarded by GCR and other sources of radiation.  Aluminum is still the material of choice whether you choose to acknowledge your error or not.

I contend the path of the TLI is the determining factor and it is a fortuitous consequence that this path takes an oblique angle through the VAB.

It wasn't "fortuitous."  It was planned that way.  Dr. James Van Allen himself helped plan the trajectories specifically with the goal of minimizing exposure to trapped radiation.  You spent several hours trying to fumble and bluff your way through a discussion of orbital maneuvers, and you still seem to think you got away with it.

Fuel was the determining factor.

Fuel is one of several factors that affect mission planning, and it did not materially limit which translunar trajectories could be attained, especially with the hybrid trajectory (which you still have not addressed).  Desired landing site, relative positions of Moon, Earth, and Sun, solar weather are other factors in mission planning.

I stand by my statements.

Your statements have been shown to be naive and simplistic, especially on the subject lately of orbital mechanics.  Not unexpected for someone who admits he has no appropriate qualifications, training, or experience.  Again, the reader must decide who is most likely right on the subject of astrophysics and astrodynamics -- tens of thousands of trained, experienced, and knowledgeable professionals, or an electrician named Tim.

I read the TLI launch was pioneered and proven by the Russians and the Americans adapted it.  Go figure...

[timfinch]

The author speaks of shielding electron radiation in the VAB,  Electrons can be attenuated by aluminum.

That's the context in which we discussed what materials to use as shielding.  It was a general discussion.  Most missions I have worked with both traverse the Van Allen belts and spend considerable time in cislunar space bombarded by GCR and other sources of radiation.  Aluminum is still the material of choice whether you choose to acknowledge your error or not.

I contend the path of the TLI is the determining factor and it is a fortuitous consequence that this path takes an oblique angle through the VAB.

It wasn't "fortuitous."  It was planned that way.  Dr. James Van Allen himself helped plan the trajectories specifically with the goal of minimizing exposure to trapped radiation.  You spent several hours trying to fumble and bluff your way through a discussion of orbital maneuvers, and you still seem to think you got away with it.

Fuel was the determining factor.

Fuel is one of several factors that affect mission planning, and it did not materially limit which translunar trajectories could be attained, especially with the hybrid trajectory (which you still have not addressed).  Desired landing site, relative positions of Moon, Earth, and Sun, solar weather are other factors in mission planning.

I stand by my statements.

Your statements have been shown to be naive and simplistic, especially on the subject lately of orbital mechanics.  Not unexpected for someone who admits he has no appropriate qualifications, training, or experience.  Again, the reader must decide who is most likely right on the subject of astrophysics and astrodynamics -- tens of thousands of trained, experienced, and knowledgeable professionals, or an electrician named Tim.

Aluminum results in a net increase in GCR radiation.  Why would it be the shielding of choice?

[JayUtah]

So am I to understand you believe the technology exist to predict SPE's to the point to provide a safety margin for lunar missions and that his technology existed during the apollo lunar missions?

I made no representations about "safety margins."  As a matter of fact, SPEs do not travel at the speed of light.  However, they are preceded by x-ray bursts which do travel at the speed of light and take only minutes to arrive at Earth.  The SPE wave front follows several hours later.  That gives the crew time to effect whatever steps they can to mitigate exposure.  There was no presumption that they would ever be perfectly safe from the most severe solar events.  For example, had one occurred when the crews were on the lunar surface, the plan was to immediately return to the LM, take off, and rendezvous with the CSM.  In lunar orbit their exposure would have been cut roughly in half.

[MBDK]

So am I to understand you believe the technology exist to predict SPE's to the point to provide a safety margin for lunar missions and that his technology existed during the apollo lunar missions?
[/quote]

Darned good question, as you have yet to show much ability to understand any of the principles involved.  You still haven't answered my question regarding your cherry-picking within your own reference.  How do you explain that?

[timfinch]

So am I to understand you believe the technology exist to predict SPE's to the point to provide a safety margin for lunar missions and that his technology existed during the apollo lunar missions?

I made no representations about "safety margins."  As a matter of fact, SPEs do not travel at the speed of light.  However, they are preceded by x-ray bursts which do travel at the speed of light and take only minutes to arrive at Earth.  The SPE wave front follows several hours later.  That gives the crew time to effect whatever steps they can to mitigate exposure.  There was no presumption that they would ever be perfectly safe from the most severe solar events.  For example, had one occurred when the crews were on the lunar surface, the plan was to immediately return to the LM, take off, and rendezvous with the CSM.  In lunar orbit their exposure would have been cut roughly in half.

There is a considerable difference between detecting and predicting.  Is he not correct in saying SPE's cannot be predicted?

[timfinch]

So am I to understand you believe the technology exist to predict SPE's to the point to provide a safety margin for lunar missions and that his technology existed during the apollo lunar missions?

Darned good question, as you have yet to show much ability to understand any of the principles involved.  You still haven't answered my question regarding your cherry-picking within your own reference.  How do you explain that?
[/quote]

I see no point of conflict with any of my stated positions by the author.  Hence no need to cherry pick.