STOP CASSINI Newsletter #9 -- May 5th, 1997

An answer to a statement from NASA/JPL regarding launch accidents.

By Russell D. Hoffman

Copyright (c) 1997

STOP CASSINI Newsletters Index


I received the email below this morning and thought it would be a good idea to simply share my answer with the newsletter recipients. It's just one brief question and one reasonably brief answer.

Thanks, Russell Hoffman, Webmaster, STOP CASSINI


Subject: Answer to a NASA JPL FAQ statement.

****** VOLUME #9 May 5th, 1997 ******

By Russell D. Hoffman
Copyright (c) Russell D. Hoffman


At 11:37 AM 5/5/97 -0400, someone sent this email: Hi,
This may be redundant, but do you think it's worth mentioning that even according to NASA itself, there's a 5% chance of failure with the launch?

What is the probability of an accident between launch and leaving Earth orbit that might release plutonium?

While it is estimated that the probability of a Cassini launch failure is about 1 in 20, most failures would not result in a release of plutonium. Though more detailed assessments are underway, initial estimates are that about 1 in 25 Titan IV/Centaur failures could to result in releases of small quantities of plutonium dioxide to the environment. It is possible that there could be small releases of plutonium dioxide particles from some RTG components, but if the components strike water there would be no release. None of the releases are expected to result in any cancer fatalities in the exposed population.

*end excerpt*


To me, this is an example of NASA's favorite tactic: GREAT OVERSIMPLIFICATION.

NASA condenses complex equations into simple yes-no answers. I believe that is wrong of our Government in general. NASA should present facts, not answers. They should let us draw our own conclusions.

Specifically, NASA is (purposely, I assume) confusing and condensing the many different aspects of the launch into one thing -- a 1 in 20 failure rate. But in reality, a launch failure over Florida is undoubtedly likely to be far less dangerous than a failure just a few minutes later and thousands of miles per hour faster, over Africa and then Madagascar. Shortly thereafter, the final push out of Earth's gravitational field (the first time) runs additional levels of dangers.

At each step, the likelihood of an accident goes down. But, the severity of the 'typical' accident goes way, way up. NASA averages all these things together.

Then they take it a step further. They talk about the most likely accidents: "1 in 25 Titan IV/Centaur failures could to (sic) result in releases of small quantities of plutonium dioxide to the environment".

They don't talk about the rarer, far more dangerous accidents. We have no way of knowing, from NASA data, (not that we would trust it) what the chances are of an accident that could release not "small quantities" but LARGE QUANTITIES of plutonium dioxide to the environment. Perhaps NASA is right: It is not 1 in 25. But is it 1 in 250? 1 in 2,500? 1 in 25,000? NASA isn't saying, and is in fact avoiding the issue completely. NASA talks about "the most likely accidents" and then talks about the plutonium release from *those* accidents. Those are the very accidents we really don't care much about.

On top of all this, I doubt NASA completely on one thing: I believe that there are many reasonable LAUNCH accident scenarios (as opposed to FLYBY accident scenarios, which I discuss elsewhere, in a number of documents) that can result in a SIGNIFICANT burn of the RTGs. Accidents where the rocket forces itself into the ground, for example, or where it is late in the launch when the rocket is traveling at very high speed. Also, accidents in which the liquid fuel components explode can expose the RTGs to wildly varying -- and widely varying -- pressure and temperature situations. Some RTGs could be torn apart and their plutonium contents burned (remember how hot the Pu-238 is to begin with -- about 1100 degrees celsius).

NASA should be obligated to talk about these things, if only to prove that they actually understand the true potential consequences of their actions. Right now, it does not appear that they do, from what few references in NASA literature there are to true "worst case" scenarios.

What would just one ounce of the 1150+ ounces of plutonium on board Cassini do to Florida if somehow it WAS incinerated? One ounce is less than .1% of the RTGs. Dr. Helen Caldicott, and Drs. Gofman, Morgan, Sternglass, Gould, and many, many others would say one thing (approximately). NASA would say another. But instead NASA actually says nothing! How can that be right? Just one ounce, just one ounce in more than 1150 ounces. One ounce could destroy many square miles of land and all the people on it and no one should doubt that that is true. Evacuation may be extremely difficult, especially in poorer parts of the world (like most of Africa). Cleanup would be horrendous and expensive and largely ineffective. If the accident is on foreign soil the geopolitical consequences would be devastating as well. It would be a very dirty embarrassment.

NASA's idea of containment of these RTGs in the midst of an explosion that can reach pressures estimated as high as 20,000 PSI using containment vessels which have been tested to only about 2000 PSI is unrealistic. (Pressure test results are mentioned in NASA's original "Final EIS for the Cassini mission" page 2-19. You should find that entire page very discomforting.)

So you ask what I think of this comment of NASA's? I think it was written by people living in a fantasy world where nothing ever fails, and where humans are capable of perfect actions time and time again. And where we get lucky every time.

I think it is typical NASA-speak using typical NASA numbers.

I think it is a white-wash being done with hog-wash.

Sincerely, Russell D. Hoffman


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First placed online May 5th, 1997.
Last modified August 17th, 1997.
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Copyright (c) Russell D. Hoffman