What Can Go Wrong With Cassini:



by Russell D. Hoffman Copyright (c) 1997

Who are we that we would launch Cassini on the world?

Cassini is a space probe scheduled to be launched by NASA in October, 1997. It will contain over 72 pounds of plutonium, the deadliest substance known to mankind. We are doing this, not because it is necessary, but because we are arrogant. Because no one has stopped us. Alternative power sources exist--the plutonium is not necessary.

We have already created radioactive junkyards and chemical wastelands all over the country, and in many other places around the world as well, such as on remote Pacific islands, deep sea trenches, and our very groundwater and atmosphere.

What do you want to be known for?

Now, our so-called space experts want to destroy the near-earth regions of outer space. These regions are of vital importance. They are the second-most important part of the entire universe after our own lovely planet (the one we're spoiling). We cannot get to outer space--to the other planets and beyond--if we pollute near-earth orbit. And everything we put there pollutes it and every piece of pollution there destroys it.

Already, military and civilian clods in space programs around the world have placed billions of pieces of space junk in orbit in a haphazard and careless manner. It would be like throwing a bucket of buckshot out of your car every couple of yards while driving from Boston to San Diego. Or rather, a bucket of tacks for future drivers to avoid...

Only it's worse, of course, because rather than just sitting on the ground, your tacks are flying all over the roadsurface at speeds around 25,000 miles per hour, and the other drivers are required to travel at that speed as well!

And as if that wasn't bad enough, it's a 3-D game where the road surface is a multi-dimensional sky full of buckshot. Only some of it's a lot bigger than buckshot. And some is a lot smaller.

The hazard from pieces bigger than buckshot, or even the size of buckshot, is great. A piece the size of a marble has the kinetic energy of a 400 pound safe at 60 miles an hour. (NASA description.)

Things much bigger than that we can track a little bit (but not all that well, and we loose pieces regularly). But there are lots of deadly things we cannot begin to track but which could damage any ship we have ever placed in orbit or have planned for launch including Cassini.

With our radar and other surveillance systems, we can only track pieces bigger than about 4 inches in diameter (about 10,000 of them are tracked) but we cannot track them very well, and we know very well that there are 10 or 100 or 1000 pieces that could hurt us for every one that we even try to track.

So, what are our choices?

It leaves us only one choice. Chance it. Every space mission chances it. Every single mission is a lottery. A game of chance. What they are chancing is the odds of a collision with a major piece of space junk, where major is generally agreed by everyone--in and out of the space industry--as being about the size of a buckshot or BB, and certainly no bigger than a small marble. Any piece of space debris, even one the size of a pinhead, can ruin a spacecraft. Like airplanes and other high-performance, low-weight endeavors, virtually everything on the spacecraft is a vital system that must be in good working order for the mission to succeed. At millions of dollars an ounce, you can bet there are very few ounces 'wasted' on backup systems. There may be multiple computers for backup, but generally there is only one thruster in each direction, one antenna, and one of most parts. Everything is designed to work right. And everything has to work right! And everything can get knocked out by one of billions of pieces of space debris!

On Cassini, what little shielding there is around the plutonium power pack is known by all involved to be totally inadequate for many possible reentry or collision scenarios. It's really only good for certain freefall failure modes. Specifically it is designed to withstand up to about 2,000 pounds per square inch (psi) but NASA admits that pressures of nearly 20,000 psi are possible during launch! And a collision with space debris could mean still higher--vastly higher--localized pressures. If the shielding is damaged by a piece of space debris, then as the probe falls through our atmosphere it could be further torn open and it's deadly plutonium contents burned up and spread throughout our ecosystem.

And it's not even right to say that so far, we have been lucky in our space launches, so why shouldn't we continue to be lucky in the future? We may indeed be lucky in the future. But future luck doesn't depend on past luck no matter what you might have heard. Luck shines on those who don't take unnecessary chances.

And besides that, we haven't been very lucky in the past. Statistically speaking, the odds really are not very good, judging on past performance! If our present trends continue, we shall be very unlucky indeed! Of the nearly two dozen nuclear launches the U.S. has made, three have already had accidents. Russia's failure rate is even worse, including the Fall, 1996 plutonium-packed Mars probe. But the Mars probe only had about .7 pounds of plutonium: Cassini will have over 72 pounds!

Numerous space launches, with both nuclear and non-nuclear fuel cells, have resulted in dismal failures. Often, the causes are completely unknown and unknowable. Man-made space debris has been cited as a probable cause of numerous failures by Russians, Americans, and everyone else. Failures, that is, of systems that cost billions of dollars and were not supposed to fail.

Either way there is a huge loss and no one knows why. It may be space debris, it may be a loose nut out of control. Titan launch vehicles have had some dismal launch failures, and with the Cassini probe, that's only half the battle.

Two years later it gets worse.

If all goes right, Cassini is supposed to fly out of earth orbit shortly after launch. Then, it will circle Venus to pick up speed, and then fly back to earth for a close flyby and additional speed gain in 1999. How close?


The plan is to fly the spacecraft within 320 miles of earth, at a trajectory that will force it to be almost captured by our gravitational pull. If all goes according to plan it will then be flung out into the solar system.

How close is 320 miles? Out to about 75 miles, our atmosphere can exert enough force to slow the probe down and heat the probe up, and cause it to fall inwards to earth, either crashing or burning up on the way in. 320 miles is only 320-75=245 miles above that point. That's pretty close. If anything slows it, or re-aims it, or runs into it we could be staring down the throat of our own poisoned pill.

Perhaps a tiny piece of space debris (of which there are billions) will hit a guidance control system. If anything like that happens the probe could come closer to the earth than we want. If we loose contact with Cassini it could align itself aimed for earth without our being able to stop it. Earth is a pretty big target when your desired desination is barely 3 percent of earth's diameter away from earth and your aim is largely decided many millions of miles away.

It's a close shave even when it's done right!

Even a little mistake can really screw things up! This is your basic butterfly effect. If anything goes the least bit wrong, we could be in for a pretty rough ride as a species. Plutonium is a deadly killer when spread in minute quantities throughout the atmosphere and that's precisely the way Cassini can crash catastrophically. It's nothing to be casual about. There is clearly cause for concern and candor.

Instead NASA in engaged in cheap politics to keep its game alive and to pay off the various players in the field who can make a lot of money by the decision to use plutonium instead of far safer solar panels.

After the flyby with Venus, Cassini comes back to earth at a vastly increased speed. If something goes disasterously wrong and it starts coming right at us instead of right next to us (320 miles above earth's surface) don't think we can send up a rocket to collect it or even blow it up.

It will be coming nearly straight at us even if everything goes right, and so having some failure could mean it would be coming straight at us--and uncontrollable. If we did manage to smack something into it, it would STILL be coming right at us--just slower and in millions of pieces--unless we somehow did this millions of miles in outer space or with some huge projectile either significantly bigger than or traveling significantly faster than Cassini is--and a perfect shot at that! Get real! Buddy, it ain't gonna happen! If something goes wrong, we might get to watch this poison pill heading right for our collective throats for months! This would have, among other things, a chilling effect on American prestige as the world stares up at our forthcoming poisoned present.

If Cassini comes back at a shallow angle and burns up high in the atmosphere, the plutonium will spread it's increased levels of lung and other cancers more or less evenly all around the world for decades to come. If it manages to make it back to earth but the shielding is damaged or destroyed, the plutonium will probably be far more deadly in the local area where it lands--it could even cause a large area (perhaps the size of Manhattan; perhaps Manhattan itself) to become uninhabitable for thousands of years. This one space probe can most certainly do all that.

There is no engineering principal or marvel at work that can prevent such a disaster. It's called a "worst case scenario" and it's real bad. And as long as we launch the plutonium over alternative methods, there's not a bit of science involved that can prevent the 'worst case scenario'. Reduce the risk, yes. But prevent it? No.

If we launch plutonium, only being lucky will prevent it. We're not relying on technology here! We're relying on luck! This is not the high-tech wonder we were looking for! This is yesterday's flawed low-tech crud recycled as innovative space exploration. Don't buy it. It's past its expiration date.

Just a little bad luck is really all it takes. And NASA knows this. Instead of using a technological solution to the problem they decided for who-knows-what-reason to use a statistical calculation of the chances of impact with orbital debris greater than approximately 4mm during various phases of flight or some such nonsense. But don't let the high-sounding technical terminology fool you. What they mean is we are relying on luck.

We could have used a technological solution that the scientists would be proud of--European solar panels. By eliminating the plutonium power pack virtually all the dangers cited here are eliminated or reduced to millionth's of what they are when using plutonium. But instead we are using plutonium and relying on 'luck'. And NASA has not been lucky.

Let's call Cassini by what it really is: A proposal to launch chemical roulette warfare against the people of the planet earth by its own citizens! Can anyone think of a more ludicrous thing? Have we all gone mad?

Well, have we?

Aiming this 'weapon' right at our own throats when a non-nuclear option could have been purchased on the open market from Europe--our friends and allies--is truly the height of arrogance and stupidity. We should all be ashamed of ourselves as Americans and as citizens of a global community.

If that probe collides with anything that's already up there, or if its launch vehicle has virtually any kind of malfunction, there will be more than 72 pounds of plutonium spread throughout our upper atmosphere and near-earth orbital area. This is insane and the people approving it and building it should be declared so! And the people paying for it as well! That's US! In our throats indeed! Plutonium is the most deadly substance known to man, and spreading it throughout our atmosphere is the most deadly thing we can do with it.

We have to stop Cassini by whatever nonviolent means it can be done. There is no doubt as I write this that in the time left before the scheduled launch (less than a year), concerned Americans and citizens around the world can convince enough people so that an injunction or other legal means can be found to stop the Cassini probe.

We are not asking to halt space exploration. We are even willing to continue to put billions and billions of our hard-earned tax dollars into tens of thousands of employees in white lab coats just to see what they'll come up with. But it better be safe, whatever it is! We cannot risk poisoning the planet and millions of horrific deaths from yet another failed NASA science experiment!


Stop Cassini before it stops us!

Write to congress, our president, and our so-called environmentalist vice president and tell them you're fed up with nuclear power in space! It doesn't belong there!

To the best of my knowledge, the facts as presented in this article are of little dispute, most being taken directly from NASA itself. It is only the conclusions on which we (NASA vs. the environmentalists) differ. NASA says it's safe enough to launch. They try to convince us that they have 'minimized risks' significantly enough to make it safe 'in spite of the risks'. But their idea of safe enough is whatever level of safety we'll let them get away with. Cassini isn't safe and it can't be made safe.

It can't be, for one reason because they cannot prevent random collisions with billions of manmade pieces of space debris (and quite a few natural ones as well during the flight to Venus and back). They can only guess that it won't happen. They cannot engineer anything well enough to stop the possibility of disaster, even in their own minds. They don't even claim to. They merely claim the risk is low enough to satisfy their opinion of whatever a 'safe level of risk' is that will still permit them to launch.

Why risk anything?

The other reason it cannot be made safe enough is this: What level of risk is safe enough when there is an alternative that is millions of times safer--to use solar power instead? Only boondoggle politics at the highest levels permitted the shameful decision to 'go nuclear' when a safe alternative was available, and those responsible should be exposed for what they've done and publicly shamed. Nuclear power does not belong in space (or anywhere else).

Alternative power sources are available. We can do this right. In a fit of incredible arrogance or ignorance or both, NASA failed to use the safe option. We must not let human inertia push this crazy project to completion just because we were not alert enough to stop it. We have to stop Cassini before the risk is taken.

Is it too late to stop it?

It's not too late, until they press the "Ignite Stage 1 Booster Rockets" button. Even after that, the second dangerous part--the flyby with earth in 1999--can still, at least in theory, be stopped. And should be.

What About the Money?

If someone put a dumb-dumb bullet in a gun, spun the barrel, aimed it at your head, and then asked for your permission to pull the trigger, would it make any difference to you if you had paid for the bullet? "The money has already been spent" is a ludicrous reason to endanger the world this way. Would we continue a war just because we had already paid for the weapons?

by Russell D. Hoffman

The author would like to add the following to this electronically-circulated World Wide Web Internet Page:

First that citizens of other countries, especially the Soviet Union, must also tell their governments to stop this pollution. This is a global problem if ever there was one!

Also, if anyone would be willing to translate this document to other languages the author would appreciate your effort. Please contact the author if you would be willing to do this.

Please distribute this document IN ITS ENTIRETY (as a raw HTML file or printed document) or request written permission to excerpt. Please link to it rather than placing it on another server.Thank you.

You can email the URL address (shown below) of this document to our elected Government representatives. Just highlight the 'http' address, then 'cut' it into your computer's 'buffer'. Next, click on the email addresses we provide in the attached document. Tell our elected officials that you agree that we need a complete "NO PLUTONIUM IN SPACE" policy.

Source URL of this document:


List of Elected Government Officials.

Related pages at this web site:
Stop Cassini Home Page
No Nukes In Space! Not now, not ever.
Space Debris Home Page
A series of articles on this shameful problem.

This article has been presented on the World Wide Web by:

The Animated Software Company

Mail to: rhoffman@animatedsoftware.com
First placed online January 10th, 1997.
Last modified April 19th, 1997.
Webwiz: Russell D. Hoffman
Copyright (c) Russell D. Hoffman