Radiation

[Luke Pemberton]

Tis is just one of many but it is light reading so it should be easily digestible.  https://en.wikipedia.org/wiki/Health_threat_from_cosmic_rays

So to cite your own source:

Astronauts on Apollo and Skylab missions received on average 1.2 mSv/day and 1.4 mSv/day respectively.

So Apollo astronauts received a dose from GCR that is equivalent to a CT scan.

[MBDK]

Well,  a new quarter has started and I have a fresh new quota for self-righteous, blow hards.  Let's do this!

I'll lead off with a few facts for your consideration.

The current solar cycle began on January 4, 2008, with minimal activity until early 2010. It is on track to have the lowest recorded sunspot activity since accurate records began in 1750. The cycle featured a "double-peaked" solar maximum. The first peak reached 99 in 2011 and the second in early 2014 at 101. It appears likely that Cycle 24 will end in mid-2018.
This is the graph of dose rate taken by the CraTer Satellite that has been monitoring lunar radiation since 2009.  It is obvious to the casual observer that the background radiation exposure was fairly flat throughout the solar cycle punctuated by SPE events.  It can be deduced by the by even the dullest of intellects that a lunar mission would have as a minimum this background radiation of approximately .3 mgy/day.  Apollo 11 had a .22 mgy/day dose rate.  This is only possible if it never left ELO.


http://crater-web.sr.unh.edu/products.php?numplots=1&durationtype=span&ProductG111=doserates&SepGcrAllType111=all&InvCombG111=doserates_combined&DaysRangeG111=Alldays&syncdate=yes&StartEndGroup111=end&doy111=085&yeargroup111=2017&screenheight=&screenwidth=

Let us look at that data, shall we?  Without the spikes for SPE, the lunar daily average measures less than .05 cGy, which is .5mGy/day.  Fair enough, BUT to be realistic, you can look at the specific data for 2013 which is within the peaks, and thus correlates to the same approximate Sun activity period during which Apollo 11 traveled.  Look at those non-SPR numbers,
(from http://crater-web.sr.unh.edu/data/craterProducts/doserates/data/2017085/doserates_standard_2017085_alldays_allevents.txt) and you get data that is consistent from day to day:

"2456335.104166   2013   42   2013.1139840   1.333   0.734   1.000   1.8702e-02   1.7726e-02   1.8333e-02   1.0221e-02   1.5785e-02   9.0085e-03   1.5598e-02   9.2391e-03   1.6074e-02
2456335.145833   2013   42   2013.1140982   1.333   0.761   1.000   1.8404e-02   1.9054e-02   1.8450e-02   9.7684e-03   1.6187e-02   1.0216e-02   1.5965e-02   9.4166e-03   1.6368e-02
2456335.187500   2013   42   2013.1142123   1.333   0.738   1.000   1.7298e-02   1.7642e-02   1.9122e-02   8.9207e-03   1.5822e-02   8.9500e-03   1.5526e-02   1.0296e-02   1.6089e-02
2456335.229166   2013   42   2013.1143265   1.333   0.756   1.000   1.8975e-02   1.8092e-02   1.9896e-02   1.0249e-02   1.6089e-02   9.1526e-03   1.6310e-02   1.0720e-02   1.6458e-02
2456335.270833   2013   42   2013.1144406   1.333   0.742   1.000   1.8276e-02   1.7111e-02   1.8640e-02   9.6895e-03   1.5953e-02   8.3184e-03   1.5481e-02   9.7308e-03   1.6527e-02"

Now, that is a RANDOMLY picked 5 day window from 2013.  The HIGHEST dose rate recorded is .019896cGy/day, or .19896mGy/day, and the LOWEST is .0083184cGy/day, or .083184mGy/day.

Those numbers fit very neatly UNDER the Apollo 11 daily dose for their whole trip.  And just to put the slam dunk on your confusion, you STILL have failed to account for their time in LEO, which is part  of their mission exposure, and which also resulted in MUCH lower dose rates for the duration of that potion of the mission.

[Luke Pemberton]

It was heavily coated with dust which should have been radioactive.

Why should it be radioactive?

If it had been then it would not have been on public display.

The food you eat is radioactive. The rocks around you contribute significantly to background radiation. How radioactive was the suit compared to other sources of background radiation? Do you know the activity associated with the suit?

 

I have researched for months looking for any indication that lunar regolith is radioactive and have found nothing.

Maybe this answers your question.

[MBDK]

Why is it you find the truth annoying?  Is it because you realize if the surface of the moon is radioactive then it becomes obvious the astronauts never landed there?  They would have been contaminated and even ingested and breathed radioactive moon dust.  Is that why it is so annoying?

Explain to me the mechanism by which bombardment of soils with high energy protons makes the soil radioactive. Do you understand the difference between radiation and radioactivity?

Spence [the scientist] is clearly referring secondary radiation due to GCR influx. The article has used poetic licence and uses the much misaligned word radioactive rather than radiation when discussing the hazard of ionising radiation in space.

It's not a case of truth, it's a case of understanding nuclear physics. There's a difference between a truth that fits your narrative and scientific understanding.

Any high energy particle with the energy to split an atom can cause the creation of a radioactive isotope that in turn gives off a neuton that can cause an additional isotope formation.  GCR constantly bombard the surface of the moon creating radioactive isotopes that create a secondary neutron flux.  It would be absolutely amazing if the moon's surface was not radioactive.  We could build spaceships out of moon dust that would be impervious to GCR.  It is not my narrative.  I did not write the article claiming the moon is radioactive.  It is your narrative that is questioned by that article.

So now, you show you have no idea how atomic physics works regarding fission.  The nuclei of high energy particles bounce off each other like billiard balls.  It is the neutron capture by that nucleus which makes it radioactive, and that neutron must be SLOWED down to be captured.  There are only a few isotopes that can fission in such a manner as to provide a chain reaction and must be in sufficient numbers and densities for that to happen.  Other non-fissionable elements that become radioactive due to neutron bombardment are numerable, but also dependent on the element itself.  Some would, but most of the elements in the Lunar soil would not become radioactive if they were in the neutron flux of an operating reactor for decades.  Some of the elements that DID become radioactive would have half-lives that only last seconds, or less, so they would be non-detectable within a day or less.  So, your claim of radioactive Moon dust is as true as the radioactive Earth dust around us.  There is some, but of such small quantities (save a rare occasion of a collection of certain elements) the risk is insignificant.

[onebigmonkey]

Any high energy particle with the energy to split an atom can cause the creation of a radioactive isotope that in turn
gives off a neuton that can cause an additional isotope formation.

Now for that gotcha moment. So any high energy particle (GCR) with the energy to split an atom undergoes this mechanism, every single one? You're telling me that every single GCR with the energy to split a nucleus, will induce fission and produce secondary neutrons and produce radioactive isotopes, or are you saying that any high energy particle (GCR) with the energy to split an atom has the potential to undergo this mechanism. Be clear what I am asking you here, as I am looking for a clear distinction.

In any case, the primary point is that the secondary radiation created by GCR is no more than that received by a uranium miner or X-ray technician in a year. Your notion that the moon's surface is a barren radioactive wasteland that is not survivable is wrong. A point you seemed to wash over.

I am not telling you every interaction produces the fission of an atom, What I am telling you is the possibility exist at the energy levels of protons of GCR to cause fission.  It does not matter if the resultant radiation is lethal to people in the short term or even the long term.  What is important is the fact that it is radioactive.  The implications are far reaching.  If moon dust is radioactive then the samples are forgeries.  If the samples are forgeries then the landing was faked.  Do I need to continue?

What makes you think no radioactive material was recorded in Apollo samples?

The Space Suit Neil Armstrong was on display in museums and schools for years.  It was heavily coated with dust which should have been radioactive.  If it had been then it would not have been on public display.  I have researched for months looking for any indication that lunar regolith is radioactive and have found nothing.  There is indications of low levels of radiation in moon rocks but nothing on lunar dust.

Really? That's your evidence?

A museum displays a suit without appropriate health and safety clearance?

You need to go to the Preliminary Science Reports and the Lunar Science Conference proceedings - you can buy the latter on the internet. They have lots of reports on fines in the Apollo sample record.

You seem to think that every molecule on the surface is radioactive. They may have the potential to become so, but it is not a given that they are all firing off particles left right and centre. They may have been radioactive at some point and the process of decay is over. That process can take millennia, it can take days - depending on the elements involved. It might not happen at all.

[smartcooky]

I have researched for months looking for any indication that lunar regolith is radioactive and have found nothing.

And yet I found this in a 30 second Google search...

The radioactivity of the moon and planets was measured from orbiters and landers. The radioactivity of the returned lunar samples was studied with laboratory equipment. Analysis of the radioactivity data shows the bimodal structure of surfaces of the moon, Venus, Mars (ancient crust and young volcanic formations). Volcanic formations on all bodies, probably, consist of basaltic rocks. The compositions of ancient crusts are different (gabbro-anorthositic on the moon and maybe on Mars, granite-metamorphic on the earth and maybe on Venus).

http://adsabs.harvard.edu/full/1982LPSC...12.1377S

The radioactive nature of the lunar surface has been known about since the mid 1960's

Here are a reports on the Apollo 16 site

www.hq.nasa.gov/alsj/a16/A16PP-F-Regolith.pdf

http://adsabs.harvard.edu/full/1973LPSC....4.2115E

[molesworth]

Ah, I wasn't expecting a return to the debate!!

I do have a question for Mr Finch, as regards the measured, or generally accepted figures for radiation levels in space beyond the VAB.  (I originally brought it up in post #550, but I'll summarise here as well.)

I work for a company which develops data handling technologies* for spacecraft.  I'm on the software side of things, but I know our chip design folks have to consider a lot of factors about the environment their designs will be used in.  Since the data they're using is based on the generally accepted measurements and models, why aren't there a lot more failures of missions operating in these regions?

As I also noted in my previous post, it's not just NASA that's involved in determining radiation risks, but private companies and other organisations in the US, and around the world, and even small independent groups like the Lunar X-Prize teams.

Either :
a) the failure rates are being covered up, or
b) all the engineers, all over the world, are in some great conspiracy to lie about the figures, or
c) all missions outside of LEO are fakes, or
d) the space radiation environment has been correctly measured and modelled, and allows for safe design of both manned and unmanned missions

Which, in your opinion, is the explanation?


[ * The same technology has been used on well over 100 missions, including LRO, MRO and Mars Express, and will launch on BepiColombo, JWST and several other upcoming spacecraft.]

[MBDK]

Actually my post #586 showed him where his lunar surface data table actually fits in perfectly with the Apollo 11 mission doses, as it shows LOWER radiation levels than Apollo 11's .22mGy/day average (plotted for the entire mission).  So the data he provided destroyed his own theory.

[raven]

The 'ooh, scary radiation' completely ridiculous coming from someone who has purportedly worked with nuclear reactors. Just because something has a detectable level of radiation emitted from it does not mean it is actually a dangerous amount. You should know this! I'm a high school drop out, and I know this!

[timfinch]

I will remind everyone that the CraTer data revealed that the orbital lunar radiation was higher than expected because the neutron flux coming from the moon elevated levels above background GCR levels 30 to 40 percent.  The depth of penetration of the incoming flux of GCR is such that that the surface has to be radioactive to generate the neutron flux that raised levels that high.  Explain how you think this flux is possible without the surface being radioactive.

[timfinch]

Actually my post #586 showed him where his lunar surface data table actually fits in perfectly with the Apollo 11 mission doses, as it shows LOWER radiation levels than Apollo 11's .22mGy/day average (plotted for the entire mission).  So the data he provided destroyed his own theory.

The stated range for background GCR level from recorded data is 2 mgy/day at solar maximum to 2.5 times that at solar minimum.  This is last century data.  Current data indicates the range to be closer to 3+ mgy/day.  How to you account for the discrepancy?

[timfinch]

Ah, I wasn't expecting a return to the debate!!

I do have a question for Mr Finch, as regards the measured, or generally accepted figures for radiation levels in space beyond the VAB.  (I originally brought it up in post #550, but I'll summarise here as well.)

I work for a company which develops data handling technologies* for spacecraft.  I'm on the software side of things, but I know our chip design folks have to consider a lot of factors about the environment their designs will be used in.  Since the data they're using is based on the generally accepted measurements and models, why aren't there a lot more failures of missions operating in these regions?

As I also noted in my previous post, it's not just NASA that's involved in determining radiation risks, but private companies and other organisations in the US, and around the world, and even small independent groups like the Lunar X-Prize teams.

Either :
a) the failure rates are being covered up, or
b) all the engineers, all over the world, are in some great conspiracy to lie about the figures, or
c) all missions outside of LEO are fakes, or
d) the space radiation environment has been correctly measured and modelled, and allows for safe design of both manned and unmanned missions

Which, in your opinion, is the explanation?


[ * The same technology has been used on well over 100 missions, including LRO, MRO and Mars Express, and will launch on BepiColombo, JWST and several other upcoming spacecraft.]

The technology obviously exist to operate electronic equipment in the SAA and passing through the VAB.  Missions in this high radiation background have shorter life expectancies than missions that remain in LEO.  I can't begin to answer your question without comparative data.  I am sure redundancy and hardened equipment was used in designing electronic equipment for the hazards of space.  What has any of this to do with my claim that Apollo 11's mission dose is unrealistic in light of recent empirical data?

[timfinch]

There seems to be a concerted effort to distract the conversation away from the pertinent facts.  Data indicates orbit and lunar radiation levels are roughly 35% higher than background GCR levels.  CraTer data taken over the full span of a solar cycle show background radiation levels in excess of .3 mgy/day.  A transit through the VAB on any path is in excess of cislunar GCR levels.  How is it possible that Apollo 11 had a dose rate of .22 mgy/day.  This is complex math requiring and advanced degree in rocket science so I am going to need help on this one.

[bknight]

Tim, you must have cherry picked CRaTER data, because according to this report from NASA states on page 8.
Hypothetical mission doses for solar min.
Apollo-like
1 week
.007 Sv
Manageable

Does seem that high to me and from the data recorded from the missions your estimate that it is too low seems to be incorrect.

https://lunar.gsfc.nasa.gov/images/DataUsersWorkshop/CRaTER.pdf

[timfinch]

Well,  a new quarter has started and I have a fresh new quota for self-righteous, blow hards.  Let's do this!

I'll lead off with a few facts for your consideration.

The current solar cycle began on January 4, 2008, with minimal activity until early 2010. It is on track to have the lowest recorded sunspot activity since accurate records began in 1750. The cycle featured a "double-peaked" solar maximum. The first peak reached 99 in 2011 and the second in early 2014 at 101. It appears likely that Cycle 24 will end in mid-2018.
This is the graph of dose rate taken by the CraTer Satellite that has been monitoring lunar radiation since 2009.  It is obvious to the casual observer that the background radiation exposure was fairly flat throughout the solar cycle punctuated by SPE events.  It can be deduced by the by even the dullest of intellects that a lunar mission would have as a minimum this background radiation of approximately .3 mgy/day.  Apollo 11 had a .22 mgy/day dose rate.  This is only possible if it never left ELO.


http://crater-web.sr.unh.edu/products.php?numplots=1&durationtype=span&ProductG111=doserates&SepGcrAllType111=all&InvCombG111=doserates_combined&DaysRangeG111=Alldays&syncdate=yes&StartEndGroup111=end&doy111=085&yeargroup111=2017&screenheight=&screenwidth=

Let us look at that data, shall we?  Without the spikes for SPE, the lunar daily average measures less than .05 cGy, which is .5mGy/day.  Fair enough, BUT to be realistic, you can look at the specific data for 2013 which is within the peaks, and thus correlates to the same approximate Sun activity period during which Apollo 11 traveled.  Look at those non-SPR numbers,
(from http://crater-web.sr.unh.edu/data/craterProducts/doserates/data/2017085/doserates_standard_2017085_alldays_allevents.txt) and you get data that is consistent from day to day:

"2456335.104166   2013   42   2013.1139840   1.333   0.734   1.000   1.8702e-02   1.7726e-02   1.8333e-02   1.0221e-02   1.5785e-02   9.0085e-03   1.5598e-02   9.2391e-03   1.6074e-02
2456335.145833   2013   42   2013.1140982   1.333   0.761   1.000   1.8404e-02   1.9054e-02   1.8450e-02   9.7684e-03   1.6187e-02   1.0216e-02   1.5965e-02   9.4166e-03   1.6368e-02
2456335.187500   2013   42   2013.1142123   1.333   0.738   1.000   1.7298e-02   1.7642e-02   1.9122e-02   8.9207e-03   1.5822e-02   8.9500e-03   1.5526e-02   1.0296e-02   1.6089e-02
2456335.229166   2013   42   2013.1143265   1.333   0.756   1.000   1.8975e-02   1.8092e-02   1.9896e-02   1.0249e-02   1.6089e-02   9.1526e-03   1.6310e-02   1.0720e-02   1.6458e-02
2456335.270833   2013   42   2013.1144406   1.333   0.742   1.000   1.8276e-02   1.7111e-02   1.8640e-02   9.6895e-03   1.5953e-02   8.3184e-03   1.5481e-02   9.7308e-03   1.6527e-02"

Now, that is a RANDOMLY picked 5 day window from 2013.  The HIGHEST dose rate recorded is .019896cGy/day, or .19896mGy/day, and the LOWEST is .0083184cGy/day, or .083184mGy/day.

Those numbers fit very neatly UNDER the Apollo 11 daily dose for their whole trip.  And just to put the slam dunk on your confusion, you STILL have failed to account for their time in LEO, which is part  of their mission exposure, and which also resulted in MUCH lower dose rates for the duration of that potion of the mission.

I am not sure you are looking at the units for the CraTer data correctly or maybe I am not.  I thought it was in cgy/day.