STOP CASSINI Newsletter #146 -- June 29th, 1999

Copyright (c) 1999

STOP CASSINI Newsletters Index

To: Subscribers, Press, Government Officials

Subject: What is a half-life? STOP CASSINI #146

Date: June 29th, 1999

Time Frame: Cassini should be redirected to impact the moon immediately!

Today's Subjects:

(1) Finally: SC newsletter editor hears from someone at NASA!

The following email came as a shock to me, since no one as NASA has ever officially even acknowledged receiving our newsletter, let alone answer the charges we have brought against them.


At 09:35 AM 6/28/99 -0700, you wrote:
Date: Mon, 28 Jun 1999 09:35:16 -0700
To: "Russell D. Hoffman" (
From: David F Doody (
Subject: Re: A small correction is all it takes: Smash Cassini into the moon! STOP CASSINI #144 June 25th, 1999
X-UIDL: c096ab285c71425deff1f134dd3db539


Thank you.

Dave Doody
Systems Engineer
Cassini Realtime Operations


----- MY RESPONSE -----

Dear Sir,

You are not a subscriber. The STOP CASSINI newsletter is sent to you because you are a public official, whose employment is paid for with my tax dollars, and you have made statements about Cassini in public which need to be answered. The address is not your private email address, it is the way the public communicates with the Government.

You haven't even tried to answer our charges against your stupid mission. (You haven't even acknowledged reading the newsletters.) You will NOT be "unsubscribed", although this correspondence will appear in my next newsletter so others can see your desire to stick your head in the sand.


Russell Hoffman

----- END OF MY RESPONSE -----

(2) Some facts and figures about Cassini's plutonium:

Cassini has over 400,000 Curies of Plutonium on board. At launch, it was about 406,000 Curies, but there has been 2 years for it to decay, so it might be down to 402,000, maybe a little less.

Pu 238 is not "weapons grade plutonium" (Pu 239), as NASA is quick to point out, as though this were reassuring or comforting. In fact, Pu 238 is about 280 times MORE radioactive than Pu 239. What this means is that it decays about 280 times FASTER. That is, its half-life is 1/280th that of Pu 239. Pu 238's half-life, according to NASA, is 87.75 years (some technical books give a slightly different value). Pu 239, on the other hand, has a half-life about 280 times longer, or roughly 24,131 years (NASA's figure again.)

Of the 72.3 pounds of plutonium dioxide, 11.852% is oxygen and 2.413% is "other" (described as "small amounts of long-lived actinides and stable impurities" in NASA's June 1995 Environmental Impact Statement (EIS) for the Cassini mission). The rest is plutonium. Here is the full breakdown of the plutonium components, from page 2-18 of the 1995 EIS:

Fuel component (Weight % at launch) (Half-life)

Pu 236 (0.0000010%) (2.851 years)
Pu-238 (70.810%) (87.75 years)
Pu-239 (12.859%) (24,141 years)
Pu-240 (1.787%) (6,569 years)
Pu-241 (0.168%) (14.4 years)
Pu-242 (0.111%) (375,800 years)

Thus, there are 400,000+ Curies, roughly, of plutonium on board Cassini, and the vast majority of the Curies are from the Pu-238. There were (launch values) 132,920 Curies in each of three Radioactive Thermoelectric Generators (RTGs) on board, of which 130,925.20 Curies is from the Pu 238 alone. Note that there are also about 130 Radioactive Heater Units (RHUs) on board Cassini as well, each with 2.7 grams of plutonium dioxide, and each of which WILL INCINERATE in a reentry accident, according to NASA's own documentation!

How does this much plutonium compare to what was released during nuclear weapons testing? That was mostly Pu 239, so by weight, you would need about 280 times as much of it as of Pu 238 for the same amount of radioactivity (400,000+ Curies). As it turns out, that is about the amount that is believed to have been released in weapons testing -- about 440,000 Curies of Plutonium, almost all of it Pu 239. That is about 12 tons of Pu 239. If spread into the environment, Cassini's 72.3 pounds of plutonium, being mostly Pu 238, would have nearly the same radiological impact on human health (and other living things).

Regarding Pu 238 already in the environment, weapons testing, 1945 - 1974, according to NASA's June 1995 Cassini EIS (page 3-44) released about 9,000 Curies of Pu 238 into the environment. NASA's own SNAP-9A released 17,000 Curies of plutonium, again mostly Pu 238, into the environment in 1964 when it reentered Earth's atmosphere and was intentionally incinerated at high altitude (NASA had assured the public, and the late Dr. Karl Z. Morgan specifically, that there was a "one in ten million" chance of SNAP-9A reentering Earth's atmosphere, but it happened.) Page 3-44 of the 1995 EIS also indicates that "Overseas Nuclear Reprocessing Plants, 1967 - 1987" released Plutonium 238 into the environment (3,000 Curies), and Chernobyl is listed as having released 810 Curies of Pu 238. The total of these sources for Pu 238 contamination in the environment is 29,810 Curies. Cassini could increase this amount by about 400,000 Curies -- more than an order of magnitude.

In the next 50 years, over a billion people will die of cancer. The #1 reason will be cigarette smoking. But the #2 reason will be "other environmental assaults". Plutonium causes cancer, leukemia, and birth defects. Cancer is something no one needs to get. No matter how survivable modern medical technology makes it, the best way to survive cancer will always be not to get it in the first place.

Knowledge about Saturn is not worth this risk to humanity, but NASA is using Cassini as a cover-up for a military nuclear agenda, and excuses the risk as being necessary in the interest of national security. They excuse the lies, the cover-ups, the character assassination of their opponents, the arrogance -- all of it -- in the name of "national security". But national security comes from being an innovative and compassionate nation, not an arrogant and stupid one. And it comes from saving the lives of people all over the world, not from risking those lives needlessly.

-- rdh

(3) More details about plutonium and its behavior:

If you take a given weight, let's say a kilogram of Plutonium 238, the majority of the kind of plutonium on board Cassini, and the same weight, (again, let's say a kilogram) of plutonium 239, the majority of the kind used in atomic bombs, they will each have about the same actual number of atoms of plutonium, because the atomic weights are very similar.

Each atom of plutonium decays only once. When it does it shoots off an "alpha" particle which is just a helium atom without the electrons. It doesn't go very far when outside the body, a few inches in air for example, and it will not penetrate skin (which is a dead layer of cells designed over a period of eons to protect the living human cells within from external sources of radiation such as the sun).

Inside the body, however, radioactive materials irradiate the closest cells horrendously! Each alpha particle that is shot off when a plutonium atom decays is like a tiny little bullet, which cuts through the cells. The exact nature of the damage is complex, not totally understood by science, and in a sense, not entirely relevant to this discussion. What is relevant is that the damage can be done by even one alpha particle. This has been scientifically proven. (See newsletter #127, which contains a letter from Dr. John W. Gofman explaining this (his credentials are also briefly stated.)

To continue the discussion about Pu 238 versus Pu 239, the difference is that Pu 238 "explodes" about 280 times more frequently than Pu 239. By explosion I mean, the shooting off of the alpha particle. It's a tiny, tiny "nuclear" explosion, which cannot be stopped, (see Newsletter #140, the quote by W. W. Schutz, General Electric, 1951). It WILL happen, but no one can predict exactly when an individual Pu atom will decay.

For that, we must turn to statistical reasoning. That is what a "half-life" is. It is the time it takes for half of a large sample of atoms to decay. It is a value which can be determined with extreme accuracy for a large sample, but if you had only one atom of plutonium, you would have no way of knowing when it would decay. If it is plutonium 238, then chances are 50/50 that it will decay within 87.75 years. If on the other hand, it is an atom of plutonium 239, then chances are 50/50 that it would decay some time within 24,100 years.

But half the atoms in a sample will NOT have decayed within the first "half life". Of that half, what happens to them? Do they all decay in the second "half-life" and then we are done with it?

No, not at all.

What happens is that half of what is left will decay in the second half-life. Thus, in the period from 87.75 years to 175.50 years (2 X 87.75), 25% of the original sample of Pu 238, or half of what is left, will decay. And thus, 25% of the original sample would remain after the second 87.75 years.

The next 87.75 would see half the 25% that was left decay, leaving 12.5% of the sample. The next 87.75 would see that cut in half, and so on.

It is generally accepted that after 10 half-life periods, most of anything would have decayed (less than a thousandth of the original quantity would be left), and after 20 half-lifes, where less than a millionth of something would be left, that it is as good as "transmutated". For Pu 239, that is about 500,000 years. For Pu 238, it is about 2,000 years.

This leads to the question: Which is worse? Something with a long half-life or something with a short half-life? It depends really on what you do with it -- do you plan to store it, or do you plan to spread it around the environment (or do you plan to try to rocket into space, which risks spreading in around instead)?

If you want to keep something which is radioactive away from human life, then it is better for it to have a short half-life, because then you only need to worry about it for a comparatively little while. Some radioactive substances have half-lives of billions of years, for instance. That's basically always going to be radioactive, since by the time it has decayed to where a "large sample" is not radioactive, the sun will have gone super-nova and swallowed Earth in its hellfire! Such substances must be carefully stored forever, at a cost we simply cannot imagine, since we have no idea how it will be done.

Something with a short half-life means that smaller samples give off the same amount of radiation as larger samples of things with longer half-lifes. Such is the case with Cassini's plutonium 238 compared to the more commonly understood variety, that used for nuclear weapons, Pu 239. It is a well-accepted statement that "27 micrograms" (See newsletter #141 for how this value is determined) of plutonium 239 is enough to cause a lung cancer in anyone who inhales such a quantity. Pu 238, being about 280 times more radioactive (that is, having a half-life about 280 times shorter), would require 1/280th of that amount, or about a tenth of a millionth of a gram, for the same effect, for any particle inhaled or ingested into the body.

Thus, Pu 238, with its very short half-life, is dangerous in far smaller quantities, than Pu 239 with its much longer half-life. There is, in fact, an inverse proportion of half-life to danger-per-weight, because in every other respect, the two atoms are very similar to each other. They weigh almost the same and have nearly identical chemical properties.

NASA's decision to risk spreading vaporized plutonium 238 into the atmosphere is the most insane thing a human being could possibly want to risk! If Pu 238 is vaporized, it will create "a spectrum of sizes" of particles as the late Dr. Karl Z. Morgan put it to me in a conversation I had with him when I first got involved with Cassini over two years ago. Most will be far smaller than a tenth of a microgram, and so NASA claims that these smaller particles are virtually harmless. But that is NOT TRUE! They are proportionally just as dangerous! In other words, if you have a particle that is a thousandth the size of one that will cause cancer for sure when deposited in a human lung, then that smaller particle will have a thousandth as much chance of causing cancer.

If you have a particle which is a millionth the size of a particle that will "for sure" cause a lung cancer (again, that would be about 27 micrograms for Pu 239, and about one tenth of a microgram for Pu 238) then that millionth-sized particle will have a millionth-chance of causing a lung cancer. But the chance will not be zero. (And NASA's own documents indicate that "5 billion" of the population might get SOME plutonium in their systems from a Cassini reentry accident!)

Thus, spreading Cassini's plutonium into the upper atmosphere is a trick NASA is playing with human lives. It is a trick that will make it impossible to identify who gets a cancer, leukemia, or birth defect from Cassini, but those effects WILL happen if Cassini reenters the Earth's atmosphere on August 18th,1999. If it does, there WILL be a release of plutonium into the environment! Perhaps half a pound, perhaps 10 pounds, perhaps the full 72.3 pounds (about 33 kilograms), or roughly 400,000 Curies of plutonium, will be dispersed into the environment. Sane people do not gamble with other people's lives like that.

-- rdh

(4) A nuclear EMP as it relates to hospitals and nuclear power plants

Readers may recall a series of letters to and from a certain Jeff Nyquist, writer for World Net Daily ( These letters concerned the effects of nuclear war and the effects of the Electromagnetic Pulse which accompanies any nuclear blast. They appeared in newsletters #128, #129, #132, #133, #134 and #135. On June 27th, I sent Jeff Nyquist the following letter regarding an article published in SPACE NEWS, which we discussed in the previous newsletter (#145):


Mr. Nyquist,

Here's a place where you can learn something important without having to listen to me, whom you obviously don't believe (though you should).

Check out SPACE NEWS, June 28th, 1999, page 17: "Energy Pulses Called an Overlooked Threat". For you, it should be quite an eye-opener (but don't think even it tells the WHOLE story. For that, you'll just have to listen to me after all!)

-- Russell Hoffman



At 10:22 PM 6/27/99 +0000, J. R. Nyquist wrote:

I understand about EMP. I've written about it elsewhere. However, I do not believe that it would cause nuclear plants to melt down.



I responded immediately with, "If that's what you don't believe, you haven't studied it very well." I followed that up with the following more in-depth discussion of the electromagnetic pulse:


SUBJECT: Mr. Nyquist: Exactly how certain of this are you?

Mr. Nyquist,

Regarding your statement [shown above], exactly how certain of this are you? 100%? 99.999%? 99%? 90%? 51%?

Because you're talking about what would lay waste to millions of acres of land, kill hundreds of thousands or even millions of people, and destroy the infrastructure of the nation. Don't forget, Mr. Nyquist, TMI was NOT a meltdown (okay, maybe just a little bit). Chernobyl wasn't even a "worst case scenario" by any stretch of the imagination! It was not a "China Syndrome". It was the start of one. Are you aware of that fact? How sure are you that a nuclear EMP would not effect the nuclear power plants in America?

Is this sureness based on your assumption that the EMP would simply not be that strong for anything? Or is it that nuclear power plants are uniquely not vulnerable, because they all have old, outdated equipment? Because if just ONE vital piece of the complex nuclear plant has been upgraded to today's digital technology, such as more efficient electronic controllers for the hundreds of pumps, or various display and control panels in the control room -- if any of these are the least bit "modern", then the EMP could be catastrophic for that nuclear power plant. Or do you disagree with that statement? If so, state which nuclear power plants you think have NOT ONE VITAL PIECE OF COMPUTER EQUIPMENT IN THEM so someone can check your facts.

If you really understand the EMP, then you know it would also destroy all the fine electronics in every hospital in the country. One EMP would do that. With all the fancy hospital equipment destroyed, then even the smallest of nuclear wars (just a minor holocaust, you might say) would turn into a global horror, since infections could not be treated, broken bones could not be x-rayed, operations could not be performed. Oh sure, you could still stick a scalpel in someone, but have you visited a modern hospital lately? They are high-tech wonders. They are completely vulnerable to the EMP. Even the emergency lighting systems would undoubtedly fail.

One last question. Why haven't you published a link to our rebuttals of your statements, especially after asking if *I* had the decency to publish YOUR absurd statements (which I did, and will do again)? Are you afraid your readers might see the logic of our position and the absurdity of yours (I don't blame you if you are)?


Russell Hoffman


Any subscribers in Maryland who are represented by Roscoe Bartlett (R-Md) are implored to pass our comments on to him. -- rdh

(5) Interesting web site: Free anti-war banners for the www and print:

Visit this ultra-cool web site for graphic art you can use at your web site for free!


(6) What you can do today to stop the Cassini flyby of Earth:

To learn about the absurd excuses NASA used to launch Cassini in 1997, ask them for the June, 1995 Environmental Impact Statement for the Cassini Mission. At the same time, be sure to ask them for ANY and ALL documentation available on future uses of plutonium in space, including MILITARY, CIVILIAN, or "OTHER" (just in case they make a new category somehow!). To get this information, contact:

Cassini Public Information
Jet Propulsion Laboratory
4800 Oak Grove Drive
Pasadena CA 91109
(818) 354-5011 or
(818) 354-6478

NASA states that they do not have the resources anymore to answer most emails they receive. Liars! They have $13 billion dollars to play with. They can answer the public's questions!

Here's NASA's "comments" email address:

Daniel Goldin is the head of NASA. Here's his email address: or

Here's the NASA URL to find additional addresses to submit written questions to:


Be sure to "cc" the president and VP and your senators and congresspeople, too.

Always include your full name and postal address in all correspondence to any Government official of any country.

(7) Subscription information

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