he is a troll forget it you are banging your heads. and he is laughing. And don't give me ther old rope about the 'lurkers' they have all seen it a dozen times.

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I´ve just found some specific article that may help the OP understand.

http://klabs.org/richcontent/Tutoria...th_program.htm

Just my two cents.

Sorry for my english.

Doubtful, since that primarily is pointing out the issues with the radiation environment and long term exposure. The fact is we know how much the Apollo astronauts received, and that's already been discussed.

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I say there is an invisible elf in my backyard. How do you prove that I am wrong?

Disclaimer: Avatar is not an official NASA image and does not imply any specific interplanetary or interstellar capability.

The Leif Ericson Cruiser

No one's forcing you to read, Cap. Personally, I find the information fascinating.

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Gillian

"Now everyone was giving her that kind of look UFOlogists get when they suddenly say, 'Hey, if you shade your eyes you can see it is just a flock of geese after all.'"

"You can't erase icing."

"I can't believe it doesn't work! I found it on the internet, man!"

FWIW here is the wiki article on radiation poisoning, specifically the link points to the bit on different dosages. Radiation toxicity depends on time exposed and dose, now we have a source stating that the astronauts received less than 5 rem, according to the wiki link this dose wouldn't even induce a drop in red cell count (I'm tempted to say biochemical changes but I don't think that's really correct given that the risk of cancer in the long term is affected).

They weren't just exposed for a few days. More 3-4 days on the moon. 8 days transit. More like 12 to 14 days exposed to Cosmic radiation.

SLF,
The spacecraft was built with shielding of the space radiation in mind...what in the normal environment would not be attenuated or stopped by a inch of aluminum, and layers of insulating materials?
...and lead isn't necessary to stop radiation out there...for the inevitable raising of the issue.

More like 12 to 14 days exposed to Cosmic radiation.

Make up your mind. In your first post you say
And you've been harping consistently on the notion "the moon is radioactive" and waving your hands wildly about neutron scattering and all this other stuff related only to the lunar surface itself. Now that your feet are being held to the fire on that point, you try to change horses and talk about the translunar coast instead.

The fact remains that you have absolutely no idea how much radiation exposure the Apollo astronauts would have been subjected to on the lunar surface, in lunar orbit, in Earth orbit, on the way there or back, or even standing in a NASA parking lot. You have absolutely no idea how much radiation exposure is required to cause health problems, DNA damage, or death. You have absolutely no idea what the quantitative difference in the radiation parameters might be in a 15-minute suborbital flight, a 12-day lunar mission, a 6-month ISS sojourn, or a 2-year Mars mission.

You haven't so far been able to express one single aspect of your belief in terms of an actual quantity. You simply wave your hands and claim it's "dangerous."

The time has come for you to put up or pipe down. Give actual numbers for the radiation exposures relevant to your claims, and tell how you arrived at them. This is the second formal request for that information. The board rules require you to respond as a condition of continued participation.

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"Facts are stubborn things." --John Adams
Clavius Moon Base

First of all I'd like to point out that the command module was MUCH better shielded than the lunar module. While in cis-lunar space inside the command module the astronauts were completely safe from radiation from every source for a period of days or even weeks, the only concern came during lunar landings when two astronauts would be fairly vulnerable to solar events, none of which occured during the apollo missions. I got tired of not seeing any numbers on this thread, so here's some hard numbers; a chart of the radiation doses sustained by the various apollo crews in rads: Very low results, of course, not nearly enough to cause any sickness or medical issues. If you accept that their short stays on the lunar surface wouldn't be lethal, then you have to accept that their longer transit times are actually safer due to greater shielding. As jay already pointed out, first you were ranting about the lunar surface being dangerous due to neutron radiation (despite the fact that neutron radiation was barely detectable compared to other sources), now you reverse heading entirely and claim that cislunar space was MORE dangerous? That just doesn't add up in the slightest. If you think it does, post your quantitative evidence.

While in cis-lunar space inside the command module the astronauts were completely safe from radiation from every source for a period of days or even weeks.

Not from every source. Certainly from the ambient and from most solar events. However, the X-class event in August(?) 1972 would have exposed an Apollo crew in the CM to a substantial dose. But of course there was no mission in progress when that event occurred, and there was only that one event of such magnitude in the entire Apollo operational period 1969-1972. There were only three events during that same period (that and two lesser ones) that would have produced biologically observable effects.

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"Facts are stubborn things." --John Adams
Clavius Moon Base

I also repeat, for the 2nd time:
Please see bold, italic, underlined, red text.

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I was just sitting here contemplating the immortal words of Socrates who said, "I drank what?"

"Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot." --Carl Sagan "Pale Blue Dot"

I concede. Until I find some some new evidence.

NASA claims that, provided they were in the command module, the astronauts would have survived the Auguest 4-9 1972 event (at least long enough to complete the mission). I stand corrected as far as them being "totally" safe, and I guess their survivability is debatable had they encountered that X-class event, but here's what a report from Johnson Spac Center says about it:

"In terms of hazard to crewmen in the heavy, well shielded Command Module, even one of the largest solar-particle event series on record (August 4-9, 1972) would not have caused any impairment of crewmember functions or ability of the crewmen to complete their mission safely. It is estimated that within the Command Module during this event the crewmen would have received a dose of 360 rads[*] to their skin and 35 rads to their blood-forming organs (bone and spleen)."
-RADIATION PROTECTION AND INSTRUMENTATION, J. Vernon Bailey, LJSC

Obviously the point stands that in any solar event you're far better off in the command module than in the lunar module or on an eva.

now lets take these exposure levels and compare them to a symptom chart

So if the astronauts would have been in an environment that was completely unsurvivable (100% fatality) they would have needed a short-term exposure of 600 or more rads. The worst exposure was A14 at 1.14 rads. They launched on January 31, and landed February 5th. It took them 6 days to rack up 1.14 rads. In order to get over 600, they would have needed to be in space, with the same radiation conditions, for 3,157 days, or roughly 8 1/2 years (not exactly short-term!).

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I was just sitting here contemplating the immortal words of Socrates who said, "I drank what?"

"Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot." --Carl Sagan "Pale Blue Dot"

NASA claims that, provided they were in the command module, the astronauts would have survived the Auguest 4-9 1972 event (at least long enough to complete the mission).

That is correct. If normal radiation protocols had been followed, the astronauts would have recieved a substantial dose, but not a fatal dose. And the effects would not have become apparent until after the mission was concluded. NASA is here thinking about crew effectiveness in terms of mission success, along the same lines as a military mission assessment where the mission is generally considered more important than any one asset assigned to it. Nowadays that sort of amoral calculation probably wouldn't work. Intuitively we want spacecraft engineered to protect the crew because the crew are human beings worth protecting, not just so they can complete the mission.

Obviously the point stands that in any solar event you're far better off in the command module than in the lunar module or on an eva.

It stands firm. The astronauts on the lunar surface would probably have had enough advance warning of an impending particle event to return to the LM, lift off, rendezvous with the CSM and transfer to the CM prior to receiving severe exposure.

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"Facts are stubborn things." --John Adams
Clavius Moon Base

Well, here's the thing. What you had wasn't evidence; it was simply context-free misinterpretation of mostly popular articles. If you posted all these claims without evaluating them quantitatively, how will you be able to tell if the next thing you read is "evidence" or not?

Seriously. Yes, the Moon is radioactive; so is the Earth. Yes, the astronauts were exposed to ionizing radiation from space; so are you, me, and everyone else. Yes, a long-duration stay on the Moon poses considerable challenges in radiation protection; but so does a long stay on the ISS. Using your reasoning to date, I can clearly show that no one lives on Earth or the ISS. You'll get nowhere if you simply intepret what you read without context and without quantitative examination.

Also, why are you sure ("until") you'll find "new evidence"? Have you considered that you might have simply been wrong?

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"Slapping a guy on the head is just as funny now as it was eighty years ago."

Substitute ammunition for evidence and you'll have something perhaps a bit more accurate.

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"Facts are stubborn things." --John Adams
Clavius Moon Base

Why was the Apollo 14 exposure slightly higher than the other missions which landed and conducted multiple excursions to the surface?

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the ego has crashed landed

You'll see significant fluctuation anyway, especially for periods of a small number of days where short-term effects (e.g., small flares) can exert more influence on the variance. But the most likely effect is Apollo 14's more direct route through the Van Allen belts. The inclination of the translunar coast orbit is dictated in large part by the desired lunar arrival conditions, which in turn is dictated by the location of the landing site. That doesn't always play nice with the orientation of the Van Allen belts that week.

In books the solar system seems to line up nicely. In reality the solar system is a hodge-podge of objects spinning in odd orbits on planes oddly tilted to one another, all at inharmonic speeds. It fits together a little like a child's first birdhouse. Celestial mechanics is ruthlessly messy, and the messiness falls within the scope of what has to be computed and considered for space flight. The Southern Atlantic Magnetic Anomaly (notated SAA on Mission Control displays, for fans of the NASA Channel) is one example of parts of the solar system that you'd think ought to line up, but don't.

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"Facts are stubborn things." --John Adams
Clavius Moon Base

I read that the Apollo Astronauts were in the Van Allen radiation belt for a couple of hours and that you would need about 2 feet of lead to shield you from the radiation, the walls on the space craft were only thin and not even made out of lead.

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Child of the Cosmos, Student of the Universe.

Where did you read that you need two feet of lead to shield you from Van Allen belt radiation?

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"Facts are stubborn things." --John Adams
Clavius Moon Base

Where did you read that?

Any elementary textbook on radiation will tell you that lead is just about the worst material to shield against the type of radiation found in the van allen belts. It's particle readiaiton, best shielded against by thin layers of light metals such as aluminium, plastics or water. Guess what there was lots of in the Apollo spacecraft.

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"The very powerful and the very stupid have one thing in common: They don't alter their views to fit the facts, they alter the facts to fit their views." The Doctor, Doctor Who: The Face of Evil.

I read it on some Apollo conspiracy site last week, i cant remember what the address id, i'll try and find it. It was obviously just some fool talking nonsense.

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Child of the Cosmos, Student of the Universe.

I don't think it's necessary to find the exact address unless there's something else specific there you had a question about. Whether the person who said it was a fool is debatable, but the notion that you need two feet of lead to shield against the Van Allen belts for a few hours is indeed nonsense. Conspiracy theory web sites haven't historically been a reliable source of information on spacecraft design and operation.

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"Facts are stubborn things." --John Adams
Clavius Moon Base

Ah, there's your problem...

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"The very powerful and the very stupid have one thing in common: They don't alter their views to fit the facts, they alter the facts to fit their views." The Doctor, Doctor Who: The Face of Evil.

When someone says you need lead in order to shield against Van Allen belt radiation or solar radiation, that's a pretty good indicator that he hasn't studied the problem and is probably just repeating what someone else told him.

Lead, concrete, rock, and other dense materials are sometimes required to shield against strong electromagnetic wave radiation. Where the hazard is gamma rays or x-rays you would choose that kind of material.

The Van Allen belts are composed of charged particles -- protons, electrons, and helium nucleii. So is the dangerous component of solar and cosmic radiation.

Protection by shielding involves putting something between you and the particles that absorbs them. Dense materials will do that, of course, but at a price. When a charged particle is absorbed in the shielding, the absorption triggers the release of secondary radiation in the form of braking radiation. An atom's behavior when it absorbs one of these wayward particles causes its electrons to get happy briefly, and then drop back down to their ground states. That drop releases a photon. The wavelength of the photon depends on the atomic mass of the atom that did the absorbing. Lead, steel, beryllium, and other heavy metals (heavy in the sense of physical density as well as atomic mass) happen to emit secondary radiation in the x-ray band, which isn't a good thing.

Now two feet of lead will indeed shield you from Van Allen belt radiation. Also from microwaves, gamma rays, cell phone reception, your in-laws, and the effects of a modest tactical nuclear device. That's substantial shielding.

It would work in this case because the incoming charged particles would be absorbed in the outermost layer of lead while the x-rays induced there would be absorbed by the inner layers. In fact, all that would probably happen within the first few millimeters of the shielding, leaving the remaining several centimeters as dead mass.

Many materials are capable of absorbing charged particles effectively and are thus useful as shielding. If the secondary radiation shortens in wavelength as atomic mass increases, then what you need is something that has a very light atomic mass, but can occur in physical densities sufficient to put enough practical mass behind each unit area of incidence. Shielding is thus often specified as grams per square centimeter (of incident area). Hydrogen atoms are very light, but free hydrogen in gaseous form isn't dense enough to work. Its liquid and solid forms are impractical for engineering.

So we compromise by hooking that hydrogen up with other atoms into chemical compounds that can provide higher physical densities with better handling and manufacturing properties. Water will work, but it too has handling issues. We then turn to the various polymer substances that hook hydrogen onto carbon and sometimes oxygen in creative ways. One of the best candidates these days is high-density polyethylene (HDPE), the stuff they make hard-hats out of. The carbons and oxygens in these various compounds don't have as good absorption properties as the hydrogen, but they serve to hold lots of hydrogen in place and keep it physically dense and manufacturable without incurring too great a braking radiation penalty.

Many natural products such as wood and felt would be suitable shielding, if provided in enough thickness.

Aluminum also works, being an atomically light metal as well as having mechanical and thermal properties that make it a good aerospace material for other reasons. Because its braking radiation edges into dangerous territory, you need a substantial thickness of it. For missions lasting around ten years, suitable shielding for electronics such as to attenuate it to ground levels against solar flares and Van Allen belt encounters would amount to a thickness in single-digit centimeters.

Lead foil would work too, but you're going to build the spacecraft out of aluminum anyway. Why not just attenuate the incident radiation with your pressure- and load-bearing structure too, if it's sufficient? Even when proper thicknesses are contemplated (and two feet is overkill by several orders of magnitude), lead is qualitatively not the best choice.

The odd behavior of braking radiation results in some interesting behavior. If shielding is too thin it will actually increase the radiation load on the payload. As particles are trapped in the outer layers the absorption creates x-rays, which are more penetrating than the original particle. So you have a minimum shield thickness that does no more than attenuate the total radiation picture down to the unshielded level. Then you add additional shielding to attenuate the secondary.

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"Facts are stubborn things." --John Adams
Clavius Moon Base

Oh boy, happy electrons!!!! And I thought those up quarks were the only emotional sub-atomic particles.

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I was just sitting here contemplating the immortal words of Socrates who said, "I drank what?"

"Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot." --Carl Sagan "Pale Blue Dot"

Maybe that post of Jay's needs a sticky...excellent explanation for us laymen.

The photon is the atomic hangover that results from electrons on a weekend returning to the Monday morning ground state. The more heinously populated the atom, the more annoying the hangover.

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"Facts are stubborn things." --John Adams
Clavius Moon Base