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Cassini visits Earth
mwillis writes " Between 8:22 PM PDT and 8:51 PM PDT on August 17, Cassini swung by earth for a gravity assist, coming about 725 miles from the Earth's surface. It still needs a Jupiter flyby before reaching its target, Saturn. Video and mission status here " /sarcasm And, despite fears to the contrary, Cassini didn't smash into the planet and spread 75 pounds of Plutonium across the surface of the planet.
6 billion people, plus, lots and lots of pets, livestock, wildlife...
We could go on forever, just make a short post responding to this asking about content. It'll be fun, really...
1) Do you live near power lines? Would you want people to stop using electrical power because there may be a link between magnetic fields induced by these and birth defects?
2) How about powerful radio transmitters?
3) The Earth has a natural ground emission of approx. 1 milli-Sievert - do you intend to move to a less radioactive piece of rock?
Your reply is just techno-phobe insanity.
There is still a direct cause-effect relationship between power-lines and plummeting property values.
"The number of suckers born each minute doubles every 18 months."
-jafac's law
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
All I know, is for the money I spent, the fucker better damn well WORK when it gets there.
I think for every probe that goes out and fails due to a programming glitch or defective anntenna, should be insured, and that insurance money should be paid to ME in the form a of a TAX REFUND. Same for expensive military contractors that run projects grossly overbudget and behind schedule. (Like THAAD, and F-22).
Otherwise, I'm all for sending chunks of plutonium into space. Park that sucker in my garage for all I care.
"The number of suckers born each minute doubles every 18 months."
-jafac's law
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
Amen, brother!
Meow!
Windows is the Acme of computing -- in the Wile E. Coyote sense.
"That means that some 9,000 pounds of metallic plutonium has been circulating in our atmosphere for
.
some decades now. We apparently survived, although how well is a matter of debate."
If you've ever looked at the curve of overall cancer rates around the world, how there was a steep climb in the 60's, 70's, it kind of levelled off in the 80's, and kind of declined in the 90's, perhaps there was a relationship there somewhere afterall. .
"The number of suckers born each minute doubles every 18 months."
-jafac's law
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
In short, all the best for the probe and I do hope it will give us more insight about what is out there but many people here did not behave like nerds but like jerks and no, although or perhaps because I've got a physics background I am not in atomic energy either but I know the reason and can tell you why instead of flaming around like an idiot.
Sorry for the rant.
No, I doubt that the yammerheads did much reading on the subject at all, outside of alarmist articles.
Altering Cassini's trajectory to any significant degree would require an impact with a BIG piece of space junk. And those are the ones that are kept track of. Hitting a stray piece of junk might damage or destroy the probe, but unless it hits something with a lot of mass, the resulting debris will just continue on along the same path.
Unfortunately many (but not all) environmentalists seem to focus on the things that aren't significant even if things go wrong -- or they cause people to build coal power plants which will cause environmental damage instead of nuclear plants. I have seen claimed that the environmental movements are trying to block the safe storage of nuclear waste because it would remove one of the arguments against using nuclear power (this was in Sweden, in particular.)
The Christic Idiots were demanding that Galileo be deflected away from earth. Apparently, they didn't realise that the probe and it's RTG's would still be in an orbit that crossed earth's. Fortunatly, they were ignored, and all that evil, nasty, poisonious :) Pu is now safely parked in orbit around Jupiter.
I find it very interesting to take a look at all of the people out there that can become emotional about issues like this with only one group of people makeing it an issue : The Media... When the media says something a large group of people break out into a chorus of "of course it is true... They wouldn't put it on TV if it wasn't..." They then take a look at the evil scientists whom they don't understand, and say "all you care about is your experiments, you could don't mind risking the planet for them, or at least havn't thought things through enough". When the scientist tries as hard as he can to convince people, he is horribly at a loss when he comes against the media's grip on the american mind. I could create a campaign right now to "End all Electro-Magnetic Radiation". It is true that electro magnetic radiation is responsible for a large number of birth defects every year, for cancers of almost all types. It is also just sunlight, and yes enough sunlight can kill you, but that doesn't mean that we need to worry about walking from our house to our car. People need to get a grip on their imaginations. Everything that sounds evil isn't necessarily, and everything that is on TV isn't true. Information is everywhere, but some have a tighter grip on it than others, and unless you listen closesly, the little voice of science will be lost in the sea of hype and emotionalism.
Sounds like Freeman Dyson. Either _Imagined Worlds_ or _Disturbing the Universe_.
Would you put your pregnant wife on a 747 from NY to LA?
Let your kids play in the basement very much? Even if you don't have a basement, I'm sure that you let doctors use X-rays on them.
Radiation is not something horrible thing evil mad scientists and the military industrial complex inflict upon the world. It's a fact of life. Mother Nature is loaded with the stuff. Take all the radiation in Cassini's RTG's and spread it out, you don't have to spread it very far to make it reach the same level as the natural background. If, however, you don't spread it out very far, then it's that much easier to contain and clean up.
What people are saying here isn't "techo-macho insanity". It's a realization that while everything has some risk, just because some microscopic risk is mentioned in the same breath as Horrible Evil Radiation isn't call to abandon all your rationality. People who don't know a Neutron from a Neutrino from their own Nuts are the most likely to get all worked up over such nothings.
Oh wait. I forgot. The reason that most all the people who actually know something about radiation and nuclear science aren't the ones who are freaking out is because we're all Evil Mad Scientists and part of the aforementioned Military Industrial Complex.
Fear of the Unknown. Had they lived 200 years ago, the same people who were picketing Cassini's launch would have been first in line to burn the neighborhood weird old lady as a witch when the village's cows got sick.
Alec
PS - don't forget to turn out the sun before you leave! Fusion! Oh the Humanity!
Twit.
Well I guess that just blew them away! Seriously though, the risk of accident is increased at zero altitude (ie launch) and the number of launches that NASA will continue making with radioactive material on board. Also, I really do not trust NASA especially considering how they 'fixed' the data for O-ring failure for the space shuttle but still launched anyway. Fear. -kojak
Ha ha.. Okay, the sun can stay, but only until we find some kind of granola powered source of all life..
I never understood why space flight isn't commercially sponsored yet. (or is it?) I'm sure certain companies would pay a fortune to be the first softdrink on mars, and apparently exploring the surface of mars with a little robot costs about the same as a major Hollywood production...
---
http://www.altavista.com/cgi-bin/query?pg=q&kl=XX& stype=stext&q=narcissistic+personality+d isorder
Imagine a cluster made from these satellites! Or better, a cluster made of people, all running linux - a 6 billion node computer!! I wouldnt mind having that in my bedroom!
I am as well fairy surprised at the disregard for the Cassini protest displayed here.
I myself do not doubt the abilities of scientists and their system of differential equations which predict the path of the spacecraft, under the nearly-ideal conditions of space.
Here is what I have to mention: If this whole operation was really so completely safe that "nothing could possibly go wrong - and if it did, we could fix it", then why would NASA go to the trouble to manufacture the safety mechanisms? I mean, if there is a ZERO percent chance of re-entry, then why bother with the extensive protection of the plutonium for the condition of re-entry? To protect it from a malfunctioned lauch?? If this is a "SAFE" operation to launch plutonium, then I am assuming that the craft is -not- going to be exploding! The fact of the matter is, there was risk involved. No matter how small, it was enough to make these scientists take extra precautions. Furthermore, how can we really test those safety methods, short of recreating actual catastrophic explosions and re-entry conditions.
I don't see why it is necessary to put the lives of people at risk, no matter how small, for a largely trivial end. We have enough problems as it is, and encouraging people to make light of the work of scientists by not questioning their methods is only helping the blissful ignorance campaign of the Con. Hey-- plutonium in the sky is good! While we're at it, why not install Star Wars, and make the shuttle nuclear powered- now that we have conquored the solar system! And how would you like to sample some irradiated crops, while we unleash new untested strains of bacteria that wipe out entire species of "pesky" insects... so called "engineers" have been producing thousands of products for household use for decades that are now proven to cause insane cancer rates.
I love science and am a total techno-head, but I just don't see the point of indifferent behavior towards the people who objected strongly to Cassini. Even if this was the "viewpoint of an idiot who never learned newtonian physics", this attitude does nothing to help anyone.
A W S ----------- QABO : BALA
Some kind of plutonium oxide, I imagine (sorry, my A-Level Chemistry days are fast receding into the past :o) )
That's always assuming, of course, that it got hot enough during re-entry to actually burn - it might just all melt together and fuse into one big, solid lump....
But "enough already", it didn't happen, and trust me (a Physics graduate) when I say that orbital mechanics is a well-enough understood branch of Physics that we can pretty much be completely sure of what we're doing.
(It's even simple enough to double-check the equations by hand on paper, if you mistrust computers that much)
Tim
It's official. Most of you are morons.
It isn't commercially sponsored yet because the US government won't let them go that route. Unfortunately, NASA got tied too close to the military (they were making a political move that backfired) early on, and the US Government isn't letting much in the way of private enterprise "interfere" with things. There are plenty of companies out there that already have plans and are simply waiting for the bloody US government to open up space travel to private industry. Once they do, we'll see another "billionaire boom". Arithon "Cutting the space budget really restores my faith in humanity. It eliminates dreams, goals, and ideals and lets us get straight to the business of hate, debauchery, and self-annihilation." -- Johnny Hart
I'm curious, just what technology NASA should have used, other than rockets?
Unfortunatly, the Apollo program wasn't a scientific program, it was political. The only real goal was to put men on the moon before the Russian's did. It's only luck that we managed to get any scientific goals accomplished while doing it.
No need to crash 'em. Simply robbing the probes of a proportion of their kinetic energy, slowing them into an orbit for collection or whatever, would suffice. Of course, if we're at war with someone, then crashing 'em might be of use. Kinda like that battle^H^H^H^H^H^H accident with Australia and Skylab. "We don't need nukes, we got derilect space probes and, when they run out, rocks." :-)
The Future of Human Evolution: Autonomy
apparently, enough plutonium to cause approx 8 billion inevitable cases of lung cancer
first?
Why is the universe here? -Well, where else would it be?
"Duh" The military application came FIRST. RTS generators are a spinoff from 1960's spy satellites. To use solar power Out Yonder, you'd need solar cells 100 times as efficient, or 100 times as large. That's an awfully big leap.
NASA wrote the report because they did the engineering. Sheesh! Is everyone in the anti-Cassini / anti-RTG / anti-nuke crowd a conspiracy theorist? Or, worse, are they deliberately posturing that way to prime the real conspiracy nutbars?
They're lying, people! I mean, I want to promote space travel too, but don't be a sucker because they can count on all geeks blindly supporting NASA in everything they do. We are being used.
I strongly disagree with this. NASA does not have my uncritical support. I think the glory days are gone and the few good ideas left are mostly suppressed by the bureaucrats. Dan Goldin's much ballyhooed "Cheaper, Faster, Better" program is partly hype. Look at which programs were put on the chopping block when the budget was being cut. My hat is off the the folks at JPL and elsewhere who have to put up with NASA middle management for the chance to build a Mars Surveyor, NEAR, DS1, etc, every few years.
Despite all of this, when the science side of NASA, by some miracle, does manage to fool the PHBs and build a probe, and actually puts some decent engineering into it, I don't reflexively chop off their heads. I applaud them for it.
If you really "want to promote space travel" then you'd better lose your anti-nuclear attitude and instead support advanced propulsion systems. What we have right now isn't going to get humans out of the inner solar system. Some form of advanced propulsion will eventually be needed, be it fission, fusion, or even antimatter. If you build a working system from MagSails, solar sails, or tethers, I will applaud you. But, dang it, we need something that works.
In the meantime, read the other posts in this thread to see why worrying about a simple RTG is silly when the DoE has admitted that tons of Pu was released into the air by nuke testing, and when so many other radioisotope sources spew vastly more Curies of crap into the air unchecked. (Consider the U and Th content of fly-ash from unscrubbed coal power plants for a start.)
Then for an encore, learn enough Failure Analysis to be able to intelligently check NASA's impact report for substansive errors. If you find any, I'll listen to you.
"You've crossed my Line of Death!" "What? No! Where is it?" "Here in the fine print...."
The engineers were saying don't launch. The suits (let's guess how many had liberal arts degrees) pushed for launching despite the warnings.
Plutonium is one of the most deadly substances around. Having 75 pounds of plutonium ash in the atmosphere is not considered a good thing. Not to be alarmist or forget that we have several hunders atomic weapons pointed at the world, but it is a matter not to be taken lightly.
- Why is the ninja... so deadly?
It seems that somebody has forgotten some basic physics. The deadliness of bubonic plague is based on its molecular structure; it would indeed be destroyed in descent.
The deadliness of plutonium, however, is based on its nuclear structure, which would not be affected by its descent in any way. It might be disintegrated, but it would still be plutonium.
Of course, a close approach is still is complete miss. When you are used to seeing astronomical distanced expressed in units of millions of miles, it's odd to see a figure of such a small order of magnitude.
Why is the universe here? -Well, where else would it be?
Having done that, further stretch your imagination to include the US Congress paying for a much bigger and heavier probe to Saturn. 8-)
Ironically enough, there was an another choice, but it was one that NASA rejected. Imagine the anti-nuke hysteria that would have happened if Cassini had been launched with an honest-to-God nuclear reactor, instead of just RTGs?
A fission reactor would actually be a bit safer than the RTGs, as it wouldn't need to be turned on until after the Earth fly-by. (But, RTGs are already so safe that the difference between 99.9999% and 99.99999% isn't very great.) Of course, outfitting Cassini with derivative of a SNAP reactor would mean that it would need solar cells for the E-V-E leg of the trajectory, and the reactor's emissions would probably blast the various particle instruments with spurious signals.
Probably the biggest turn-off to NASA was the lack of flight tested reactors. They wouldn't risk Cassini on a power source that hadn't been tested to run for decades.
So it comes down to solar power or RTGs, and solar just won't cut it out that far. Someday, maybe, when we have ultra lightweight and yet somehow more rigid concentrator cells. Don't hold your breath waiting for them.
"You've crossed my Line of Death!" "What? No! Where is it?" "Here in the fine print...."
There's always risk involved in anything. There's a risk right now that a lighting strike will send a surge through the wires and electrocute you while you're using the computer. There's also a risk that a metorite will hit you while you watch tv. That doesn't mean that you will stop using the computer and live in a bunker does it? If the risk is small enough then most rational people will choose to disregard it as being essentially impossible.
I don't see why it is necessary to put the lives of people at risk, no matter how small, for a largely trivial end
What about the risk that an airplane will crash into a city or that a car driving down the street will suddenly swerve and hit people. I don't see why we use airplanes and cars just to get to other places quicker when there is that risk. I would argue that the ends that airplanes and cars are used for are more trivial than the ends that Cassini is being used for.
"When you sit with a nice girl for two hours, it seems like two minutes. When you sit on a hot stove for two minutes, it
Very interesting, if true. References, please. (And especially, references that take into account the anti-smoking campaigns in the USA during the - wait for it - 80s and 90s.)
Please also explain why there should be a plateau in the 80s, if the half-life of the short lived fision products are months, days, or less, and the long lived products have half-lives of thousands or millions of years.
(Bonus points for essays on common mistakes made in epidemiology, and why correlation does not necessarily imply causation.)
"You've crossed my Line of Death!" "What? No! Where is it?" "Here in the fine print...."
Rockets in general are okay. The Air Force had developed a number of manned, piloted planes (as opposed to the NASA rockets, which were pretty much ballistic) with a combination of conventional jet engines and rocket engines.
They were reusable, achieved altitudes that were pretty close to the Mercury capsule altitudes and could land on the groud and be reused. Had the program continued they probably would have built a plane that could achieve LEO sometime in the 60's.
I don't mind using big rockets for heavy lifting, but I have always preferred the idea of establishing a space station in Earth orbit from which both small ferries to Earth and missions to the Moon (and other heavenly objects) could be launched. Von Braun also pushed for that idea, but as long as he was building big ass rockets anyway the Lunar Orbit Rendevous plan killed any chance for a permanent space station.
The International station and Mir are pipsqueaks comapred to Skylab, which rode up on one Saturn V and would still be operational today had they not put it in too low of an orbit. The thing was as big as a house.
Had things worked out differently, I think that we could have wound up with a fleet of LEO-capable space planes, a wicked huge space station and a large, permanent (or semi-permanent) base on the moon.
It's true though, that a lot of the Apollo program decisions were motivated by the political need to get to the moon by 1970 at the latest. And the rush to get there meant that no infrastructure was left to permit the space program to grow. It was a one time goal that accomplished very little in the end.
-- This and all my posts are in the public domain. I am a lawyer. I am not your lawyer, and this is not legal advice.
The laws of orbital mechanics dictate that the Earth has to lose as much kinetic energy as Cassini gains during its gravity assist maneuver? Why hasn't anybody made a big deal about *this*? After all, having nuclear material spread througout the planet would be bad, but crashing into the sun because we had too many gravity-assisted spaceflights would be far, far worse.
;)
Somebody should start a campaign to prevent NASA from using Earth for gravity assists. Our lives may depend on it!
For the humor impaired
Mod down posts with a "Free Mac Mini/iPod" sig, they're spam!
Beach is South Fla? You'd have more to worry about from the sunlight. The RTG is so well shelded that it would not come apart. The fear of "Radiation" we have is crazy. They (we, I used to be involved, very slightly in power plants) think of problems you wouldn't immagine. Things like:
There is an earthquake, which knocks down the support building, leaving the access door exposed, then an F5 tornado comes along, and picks up a telephone pole, and wings it, small end first at the door. Impact is at 300mph. The door has to hold. (I was there for the test, it held - Yes, we fired a telephone pole at the door (a sample door))
Cassini's RTG was designed to hold together through either through a launch explosion, or a worst case re-entry
-- 73 de KG2V For the Children - RKBA! "You are what you do when it counts" - the Masso
Do you homework, then come back.
Wow. You contradict yourself so badly it reaches beyond the heights of ordinary hypocrisy. You end by showing your true neo-Luddite stripes.
After raising alarms about nearly every modern endeavor from space exploration to bioengineering and raising the specter of conspiracy in science and implicitly calling peer review in science a sham (since it supports the 'Con') you call yourself a "total techno-head" who "loves science".
I'll go out on a limb and bet that there is a scenario in the Cassini mission plan that covers the case where mission control has been nuked out of existence or has been cut off by an earthquake or a hurricane. And that would mean what?
Just because NASA shows due diligence doesn't mean that every scenario they have a plan for will occur. Also, nearly every scenario is 'possible' and thus has a non-zero probability of ocurring. What would you make of that? Use it as an argument to eliminate 4.5 billion people, that are kept alive only because of (yuck!) science, and return to a pre-industrial, agrarian society?
We should invite all these corporates to Europe. I don't think ESA is prohibited from commercial sponsorship. Since they could only envisage a budget the size of NASA's in their most sordid wet dreams, they ought to put the money to good use. :)
"Cake or death!" (E. Izzard)
--
"This isn't the post you're looking for. Move along."
flame{
It just stuns me to see people resort to simple-minded name calling over this issue. This RTG issue has been beaten to death, and this unnecessary hysteria has to stop. Give me counterexamples, not insults. You cretins can all go back to your creationism classes now.
}\\flame
"I'm an old-fashioned type of guy. I worship the Sun and Moon as gods. And fear them."
Actually, British Nuclear Fuels has done a fairly good job of advertising one of their power stations as a great place for a day out with the kids. This is Sellafield, formerly, erm - Windscale. Yep, that's right, the one that leaked ever so slightly.
This is not a joke. See
http://www.bnfl.co.uk/
I guess they should know whether it's dangerous or not. They're the ones who have to work there.
"Cake or death!" (E. Izzard)
--
"This isn't the post you're looking for. Move along."
IIRC, the canister which held the plutonium was designed and tested not to crack under explosion.
n/t
Don't you think NASA has taken precautions against this? The plutonium is sealed in a ceramic like case designed to go through re-entry. In fact during the 1970's a russain space probe crashed in the ocean with the *same* plutonium fuel. Its been sitting there ever since, safe and not leaking.
As someone who thinks that the lack of a decent liberal arts education is what's leading the U.S. straight into the Toilet of History, I can't help but laugh at your comment. You seem to be implying that a "yammerhead" is someone with a liberal arts education, and that orbital mechanics should be part of the curriculum necessary to get, say, and English Literature degree.
You remind me of the engineering students I used to hang out with in college, who would in the same breath ridicule liberal arts students and then complain about the lack of intelligent programming on television. It always amazed me that such intelligent people could be so stupid.
The purpose of a good liberal arts education is to teach critical thinking and provide enough knowledge that one can make sound decisions on a wide range of issues. This is a skill that, in my opinion, most engineering, science, CIS, and business types lack outside of their fields. If there were more people with good liberal arts educations, the dialog surrounding the Cassini issue would be less hysterical on both sides.
Personally, I wasn't terribly worried about the Cassini flyby, but I can certainly understand how many people would be. Both the government and the nuclear industry have deplorable track records when it comes to safety and honesty. The pattern has repeated itself all too many times:
Anti-nuke activists: "These things are dangerous!"
Gov't/Industry: "No they're completely safe. You people don't know any science!"
Nuclear facility: BEEEEEP! BEEEEP! (releases dangerous stuff)
-or-
Nuclear facility: (silence) (slowly releases dangerous stuff, government/industry tries cover up until too many people get sick to hide it)
Anti-nuke activists: "See! They lied! Again!"
John Q. Public: "Hmmmmm.... You anti-nuke people may be a fruit and nut assortment, but you were right!"
So once again with Cassini, we had people saying it was dangerous, and we had the government and Big Government Science saying that it was safe and that Cassini's critics did not know any science. This time they happen to be right (IMHO), but to most people (who do not know and should not be expected to know orbital mechanics, the chemistry of heavy metals, or nuclear physics), this sounds like yet another refrain of that old song, "Trust Us, We're Scientists, We're the Government, We're Big Corporations, You're a Bunch of Idiots Who Can't Wipe Your Own Bottoms (Ooops! We Made a Mistake)".
The knee-jerking of so many slashdotters just adds to the distrust that many people naturally have of professional scientists, not because they fear what they don't understand, but because so many scientists or people claiming to be scientists, or people acting in the name of science, have lied, goofed, and covered up. You have absolutely no right to be angry that the "ignorant masses" don't want you playing with matches anymore. You've proven that you aren't mature enough to be trusted with them.
Fine, call me a Luddite, but until humanity develops the wisdom to handle the kind of technological power we have (and that means more liberal arts education for everyone, MWAAAHAHAHAHAA!), we should damn well have a total halt to goofing around with nuclear power sources, genetic engineering, and ecological "tweaking".
So, before you pull this Niven-Pournelle bullshit about people believing that certain kinds of technology have some sort of mystical "badness" about it, please consider that maybe we're all a little smarter than that. It's not the car that we fear, it's the idiot behind the wheel. And with good reason.
This is bogus. See the other posts in the thread for reasons why. (I.e. If 72 pounds of plutonium dioxide can do us in, then why are we alive after tons of Pu-238 were blasted into the air by above ground nuke testing.)
If we let ourselves get used to cheap, brute force crutches like plutonium fueled vehicles, we get stuck with them - they become the standard, not the bonus.
Let's clarify this -- the rocket that launched Cassini was a chemically powered vehicle. The probe itself is equipped with chemical rockets, both for the main engine and the thrusters. Pu is not Cassini's "fuel." It is its power and (to a slight extent) heat source.
Better?
Nothing makes people like that feel more secure about themselves then to believe the great machine that they're a happy little cog in runs as well as everybody promised; that real life does work exactly like the sample problems in their textbooks; that there is never any need to step back and wonder what life might look like if a few "truths" were less than true.
Did you have any specific untrue "truths" in mind? Conservation of Mass-Energy? Newtonian mechanics? (Which are being used to calculate Cassini's trajectory.)
Anyway, I take the contrary view. Before Cassini's launch I saw more news airtime given to the anti-Cassini crowd than the pro-C side. I suppose that graying scientists were a lot less dramatic than oddballs with bad haircuts carrying signs and chanting "No Nukes!" IMNSHO the "cogs in the machine" are the ones who bought the media fear-mongering.
I agree that we should have a better propulsion source, but will not halt all exploration until one is devised. After all, how many new propulsion systems have been brought on-line in the past 30 years? Is there even one? (You can't count DS1's ion engine. They've been around since the 60s. The only innovation is political -- to let the engineers finally install an ion drive as the main engine of a probe.)
Sure, upgraded series of rockets come out, but they differ only in detail from the rockets of the 60s. And, the cost to launch a pound of payload into low orbit hasn't dropped below $3000. There's something wrong here.
Assuming you live in the USA, have you written your congresscritter to support NASA's "Future X" program?
"You've crossed my Line of Death!" "What? No! Where is it?" "Here in the fine print...."
In Phoenix AZ., the enviromaniacs tried many
many times to infiltrate the power plant there,
in an attempt to *cause* an accident! They even
tried to bring down a power line tower!
OOps boss is around corner gatta go!
Antibiotics, vaccines and clean water cause cancer rates to increase. In the "good old days", most people died before they were old enough to develop cancer.
The bravado expressed on this news group indicates a high degree of scientific arrogance inappropriate for critical and skeptical thinkers, especially when one considers the many rocket disasters of late, the Challenger disaster, the many Apollo failures, and the reliance on Europeans for many critical components on board the craft. Thank you
The thing that pulls the rug out of the arguments is that RTGs have been in craft that have exploded at launch and burned up on reentry. Every RTG in those craft landed intact (although not all were recovered) I believe one was tracked into the ocean where it couldn't be recovered.
Does that eliminate all risk? Of course not, but combining the risk of the RTG actually disintegrating with the probability of the craft actually hitting the earth with the actual damage the dispersed plutonium might do, and the risks are extremely small. Oh and the risks at launch are even smaller, since even if every fuel source on every booster were to explode simultaneously with every molecule of fuel combining with with an oxidizer at the same instant (a complete impossibility) the resulting forces would at worse launch the intact RTGs away from the launch sight, but could not possibily disintegrate them.
This is bogus. See the other posts in the thread for reasons why. (I.e. If 72 pounds of plutonium dioxide can do us in, then why are we alive after tons of Pu-238 were blasted into the air by above ground nuke testing.)
ummm... i didn't think we were done counting the casualties from nuke testing yet. seems to me that plenty of people are still suffering and dying from it, not that it's being publicly acknowledged. (and, frankly, i just don't get the mentality that it's ok to do a little more of a bad thing we've done a lot of in the past; not exactly what i'd call social evolution.)
Let's clarify this -- the rocket that launched Cassini was a chemically powered vehicle. The probe itself is equipped with chemical rockets, both for the main engine and the thrusters. Pu is not Cassini's "fuel." It is its power and (to a slight extent) heat source.
Better?
Damn well better NOT be nuclear powered rockets within our atmosphere. My bad, though, shouldn't have started talking about propulsion, when I just meant power source in general.
Did you have any specific untrue "truths" in mind? Conservation of Mass-Energy? Newtonian mechanics? (Which are being used to calculate Cassini's trajectory.)
This is exactly my point. All you're thinking about is your textbook problems. Think REAL WORLD. Want some specific "truths" ?
How about things like real statistics on the amount of debris in orbit over the earth, and the accuracy to which the trajectories of every piece are truly modelled. Also, everyone seems so quick to believe the government when the government promises the casing is "explosion proof." How many times are we going to have to hear, "Well, uh, in the tests everything SEEMED fine..." Between the government's history of misinformation and the fact that testing doesn't guarantee jack, I'm sorry if I'm a little skeptical about what I'm feed as truth.
I agree that we should have a better propulsion source, but will not halt all exploration until one is devised. After all, how many new propulsion systems have been brought on-line in the past 30 years?
Sorry, but them's the breaks. I just can't condone strapping a bunch of highly toxic material to a rocket that has, what, about a 1 in 6 failure rate? Please don't tell me that it's OK because only a small part of Florida, or the Pacific Ocean, or whatever would get poisoned in the event of a disaster. No one has any right to make that sacrifice.
Assuming you live in the USA, have you written your congresscritter to support NASA's "Future X" program?
No, thanks for the tip. The truth is, I'm not exactly an activist here, just been playing devil's advocate for the sake of discussion. I will look into this, though.
I figure it took a good 30-40 years for the bulk of the plutonium dust to settle out of the atmosphere, and wash off the topsoil into the ocean, where we're exposed to much less of it. Unless that is, you eat lots of fish.
"The number of suckers born each minute doubles every 18 months."
-jafac's law
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
and the reliance on Europeans for many critical components on board the craft.
:)
You really had me going until this part
You're a looking a 75 pounds of radiactive dust spreading all over the atmosphere. Not a pretty picture. Actually, you're not. The plutonium is in the form of a ceramic, very similar to your coffee mug. Now, when you drop your coffee mug on the floor, it doesn't shatter into a fine dust, does it? No, it shatters into 2 or 3 chunks. The same for that chunk of ceramic plutonium; if you were to damage it somehow, it wouldn't pulverize into dust, it'd break into a few large chunks. Besides which, the only way something might damage the plutonium ceramic is if Cassini actually plunged into the Earth and you were to mack it with a bulldozer. Then you might get through the casing. There was such a small chance of anything remotely dangerous happening that anybody who actually knew anything just ignored Cassini and let it go on its way. The only people up in arms are the uninformed.
Still scary considering they are considering more plutonium lift offs of other probes when solar energy powered satellites can fit the bill just as well Shalom
Lets suppose for a moment that 75 pounds of plutonium *did* come hurtling through our atmosphere. First and foremost, it would probably be so badly degraded upon re-entry that it
wouldnt matter *what* it was. You could send a damn dump truck full of boubonic plague through the Earth's atmosphere, it would probably disintegrate before ever reaching the
ground. The earth is continually bombarbed by fairly large chucks of threatening debris 24 hours a day, 7 days a week, 365 days a year. Its been this way for millions, if not billions of
years. There's a _reason_ why we arent living in a sea of craters, kids.
you are talking about molecular breakdown; plutonium is an atomic particle. The heat from a nuclear explosion does not alter an atom's radioactive property so a reentry is gonna do zit. You're a looking a 75 pounds of radiactive dust spreading all over the atmosphere. Not a pretty picture.
Hasdi
The CAMPAIGN TO END NUCLEAR FUSION FOREVER is now collecting donations for its campaign to DESTROY THE SUN. As is well known, the Sun produces light and heat by EVIL NUCLEAR FUSION and MUST BE DESTROYED IMMEDIATELY! We can no longer accept the risk of living only 93 million miles from a MASSIVE FUSION REACTOR. NUCLEAR POWER MUST BE PROHIBITED IN ALL ITS FORMS.
After the successful completion of this campaign, our members will be CRYOGENICALLY FROZEN and sent to all nearby solar systems to destroy their suns as well. Only when the NEW UNIVERSAL ORDER bans EVIL FUSION POWER throughout the ENTIRE UNIVERSE will our CHILDREN and THEIR CHILDREN be able to sleep SAFELY at night without the fear of NUCLEAR CATASTROPHE. Of course after we've destroyed all the stars there will no longer be anything but night, but you get the point.
Please send all the money you can spare to Al Gore, The White House, New Babylon, DC, USA. Checks should be out to 'Algore Campaign Funds'. Thank you.
Your reply is just techno-phobe insanity.
;)
:)
Well said!
Frankly I think it must be a troll, it does that "thing" to my blood pressure, y'know, where I just wanna SCREAAAM and hit the roof...
It's also over-emotionalist claptrap
~Tim
--
~Tim
--
Rushing on down to the circle of the turn
1) Do you live near power lines? Would you want people to stop using electrical power because there may be a link between magnetic fields induced by these and birth defects?
The researcher who did this study faked his data. There is no link. This was big news a month or so ago.
...who was saying this would crash and cause...the end of the world???
That's my 1/50 of $1.00 US
JM
Big Brother is watching, vote Libertarian!!
--Justin Mitchell
"2nd Place is a fancy word for losing" --Bender (Futurama)
First of all, it is true that the worst case scenario that is painted by even the most fervent opponents of the mission is rather mild compared to other dangers that are facing us all the time. Still, I wonder why people feel the need to ridiculously downplay the dangers of plutonium. Who cares if it is really ``the most deadly substance'' - the stuff is nasty enough to cause a big headache for any organization charged with handling it responsibly.
However, the real issue is what are the benefits for us (as human beings in general) that justify putting money in the billion dollar range? Since very few people have a true interest in the advance of astronomy as a basic science, the real reason for putting so much effort in these missions are the technological spin-offs that may result. If you see it from this point of view, the Cassini mission becomes really scary!
- One ``dream'' application is the further militarization of space. Plutonium battery powered spacecraft could be smaller, less vulnerable, and less restricted in their orbits than solar or conventional fuel powered ones. Should anyone want this? - Definitely not!
- The development of civilian plutonium-based space missions helps to support a nuclear industry based on the plutonium cycle. The only people who really benefit from the plutonium cycle is the military (and I don't really think of the United States so much as they have enough nuclear bombs to blow us all up anyway). For civilian use it is a complete folly (economically as well as environmentally: The by far the worst radioactive polluters are reprocessing plants (plutonium extraction!), not from nuclear power stations).
- One the other hand, the rejection of a solar power source for Cassini meant what could have been a major push for solar power technology did not happen.
I am not making this statement as a blind advocate of solar power. But I do notice that a choice was made to spend a lot of money, officially on a basic science mission, in such a way that indirect benefits go to the military, and not to sustainable civilian uses.In short, it leads us away from responsible use of nuclear power, which I believe is possible.
Marcel (oliver@member.ams.nospam.org)
To quote the Simpsons: "For centuries Man has yearned to destroy the Sun. I'm going to do the next best thing - block it out."
Man, all you Pro-Cassini people didn't bother to mention all the engineering that was done to prevent accidents, much less post URLs for the less-clueful.
h tm
reprint:
Cassini is using 3 Radioisotope Thermoelectric Generators (minimizing chances that a single event can damage all the power sources), each of which contains 10.9 kg (24 lbs) of non-weapons grade isotope (plutonium-238 dioxide) in ceramic form (tends to break into chunks, not dust) contained in a platinum-30 rhodium alloy clad. Each RTG also has an external graphite aeroshell (a reentry shield) and a graphite insulator to protect the fuel from impacts, fires and atmospheric reentry conditions.
http://www.jpl.nasa.gov/cassini/rtg/intro2true.
-- Ender, Duke of URL
You've missed my point. Did you read the other posts on the "Pu is the world's most toxic substance" urban myth? The very fact that you and I are alive refutes that legend. And, since that seems to be the lynch-pin of your argument, it casts doubt on the rest.
Also, along the "didn't think we're done counting casualties from nuke testing yet" line, how do you separate cancers from N tests versus cancers caused by smoking, food-borne carcinogens, radon seeping up from the basement, or whatever, at this late date? Epidemiology is tricky....
In fact, I wouldn't be surprised to learn that it is dern near impossible to trace the genesis of any specific cancer more than a decade or two from the suspected exposure. (At least, not outside of the lab, which you seem to scorn as the home of unrealistic fiends who want to force-feed you Pu-239. 8-)
. . . . Want some specific "truths" ? How about things like real statistics on the amount of debris in orbit over the earth, and the accuracy to which the trajectories of every piece are truly modelled. . . . .
Ah, now you're getting down to brass tacks, instead of throwing around glittering generalities. But, none of the complaints above invalidate anything you'd learn in Physics 101. They're all textbook examples of ballistics. Horrors! ;-)
For what its worth, Space Command (or whatever agency lives under Cheyenne Mountain) tracks the trajectories of all that space junk. NASA routinely clears its orbits with them. "To what degree of accuracy?" Beats me; it's a national security secret.
But, it doesn't matter. The big stuff (say 6" across or more) is tracked by the large Schmidt cameras in Hawaii and various other locations around the world. Their orbits are known to within some classified, but small, amount of error. Anything smaller can't shift the probe's path enough to matter. Sure, one little paint chip could destroy a major subsystem, but that won't alter Cassini's orbit by even 1%. (Think conservation of momentum, another of those useless, totally divorced from the Real World, textbook concepts.)
And again, your alarm at even an infinitesimal possibility of a reentry seems to be based on an exaggerated view on the carcinogenic properties of PuO2 dispersed over some remote part of the world. This I dispute because it already happened and we didn't die. That's not a textbook problem; it's Real Life(TM) data.
In 1964, SNAP-??, installed in a military navsat, reentered the atmosphere. The RTG as designed incinerated the metallic Pu within. (This was a stupid design decision. If you want to gripe about any RTG, this is the one.)
As a result, future RTGs were designed to survive reentry. In 1968 and 1970, they did just that, in a weather satellite and Apollo 13's LEM, respectively. The weathersat RTGs were recovered, refurbished, and reused. The Apollo 13 RTGs were targeted at a deep ocean trench off of Fiji. No signs of leakage were ever discovered.
You might say, "They never really looked." Maybe they did, maybe they didn't. Either way, you're the one claiming world-shaking consequences to a RTG reentry. These happened, yet the searing waves of deadly radiation didn't scorch the life from the planet, or even the Pacific, and we're all here to tell the tale.
How many times are we going to have to hear, "Well, uh, in the tests everything SEEMED fine..." Between the government's history of misinformation and the fact that testing doesn't guarantee jack, I'm sorry if I'm a little skeptical about what I'm feed as truth.
Don't apologize, it is good to be skeptical. Doubt the government; doubt everything I write. Check and double check all assumptions and unstated conditions. Go back to the primary sources and check again.
On the other hand, don't go overboard and descend into paranoia. If the engineers really had kludged the heat shielding on the RTGs, or fudged the risk assessment on the chances of a launch explosion, why were so many of them -- and their families -- present at the launch? Wouldn't simple self-preservation send them into their cellars or on long vacations to the Yukon? 8-)
Is it not possible that they really did do a good job of protecting the RTGs and were proud enough of their work to be present at the launch?
Let me ask you this: Do you think it is even possible to build a RTG that will stand up to a launch accident?
If you don't, just say so. Nothing I write will be able to allay your fears, and we might better use the time elsewhere.
Sorry, but them's the breaks. I just can't condone strapping a bunch of highly toxic material to a rocket that has, what, about a 1 in 6 failure rate?
Again, you imply a vastly greater risk to this event that the evidence supports.
Hmmm.... That 1 in 6 claim sounds familiar. Have you been alarmed by one of those anti-Cassini web sites, the ones that can't tell the difference between a space probe and a H-bomb? If so, take every claim they make with an entire shaker of salt. More than that, is there some specific claim they've made that you would like to discuss?
"You've crossed my Line of Death!" "What? No! Where is it?" "Here in the fine print...."
- You didn't provide any references.
- You didn't justify the claimed change in cancer rates. In fact, if the Pu took 30-40 years to settle out, wouldn't we just be starting to see an increase in cancer?
- Most importantly, you didn't comment on the effects of the anti-smoking campaigns, which started bearing fruit around the time that the claimed cancer rates started dropping.
Anyway, the evidence on dust is against you. Remember Mount Pinatubo(sp?), the volcano that blew up violently in the Phillipeans about ten years ago? It injected a large amount of sulfuric acid aerosols into the stratosphere. The aerosols took only 2 to 3 years to settle down into the troposphere, where rain could wash them out. I remember this clearly, because as an amateur astronomer, I complained about the high haze caused by that acid mist, until it finally cleared. 8-)"You've crossed my Line of Death!" "What? No! Where is it?" "Here in the fine print...."
s/Pt/Pu/g. Yeah, I'm a pedant =)
"Cake or death!" (E. Izzard)
--
"This isn't the post you're looking for. Move along."
The footage you're referring to can be found on the BNFL website:
:)
Go to http://www.bnfl.co.uk/index1.html
Go to Activities -> Transport then click on "Film: Locomotive"
Enjoy
"Cake or death!" (E. Izzard)
--
"This isn't the post you're looking for. Move along."
Undoubtedly, they each sat down and ate a 75kg hunk of plutonium.
75 pounds, fine. Stupid Imperial system.
why would NASA go to the trouble to manufacture the safety mechanisms? I mean, if there is a ZERO percent chance of re-entry, then why bother with the extensive protection of the plutonium for the condition of re-entry?
The only time there was even a minutely significant chance of the probe re-entering the atmosphere was shortly after launch. The safeties were likely designed for that eventuality, not for the fly-by.
this is a "SAFE" operation to launch plutonium, then I am assuming that the craft is -not- going to be exploding!
There's no such thing as a 100% "SAFE" launch. There's always the possibility that the launch vehicle will explode on the pad, or shortly after lift-off, or perhaps later, when the probe is reaching earth orbit. Do you honestly think that such an explosion will cause a horrible radioactive dust cloud to settle down over half of the United States, killing thousands and giving cancer to countless millions? Not going to happen.
encouraging people to make light of the work of scientists by not questioning their methods is only helping the blissful ignorance campaign of the Con.
Who is encouraging this? This goes against the very foundations of science. By all means, question. But don't question US, question THEM. Read the press releases THEY'VE written, because those are the answers you're looking for, and you won't always find them here (though quite a lot of Slashdot regulars are qualified to respond).
Some people are indifferent to Cassini due to ignorance, I'll admit, but lots of us are indifferent to Cassini because we KNOW BETTER. You'll discover most all truely qualified astrophysicists and scientists were all TOTALLY comfortable with having Cassini make its pass. While they had to admit there was a slim chance of a collision (as they had to, since there's always a slim chance), that chance was somewhere in the neighborhood of 1 in several million, and getting more remote the closer Cassini came to earth.
If all of the people qualified to make decisions about something seem content that things are OK, perhaps you should give them the benefit of the doubt. NASA engineers are not stupid people. Ask your questions, sure, but don't turn a blind eye to the answers because of your own fears and doubts.
Really, we should be a little more critically-thinking than this.
Wow, you're ABSOLUTELY RIGHT. Why in the world did I ever put my trust in space flight with the DOZENS of experienced men holding PhD's in things like astrophysics and engineering when I can run around screaming with my arms up in the air with the rest of you uneducated Slashdot kiddies?
NASA isn't some sort of covert government agency bent on getting things into space no matter what the cost. The guys at NASA aren't stupid. Give the people with degrees the benefit of the doubt and leave your conspiracy theories at home.
Actually zero altitude is the least risky time for an explosion to occur. That way the Pu doesn't get spread very far and can be cleaned up. This is much less dangerous than a high altitude burn up. NASA screwed up royally with Challenger, but the fallout (no pun intended) of that incident has been much tighter safety reviews than ever before. You are correct that the risk increases with the number of launches, but if NASA's risk estimate of 1 chance in 1.2 million of a mishap is even close to correct then they will have to launch hundreds of thousands of missions before the cumulative risk becomes significant. (So far they are up to what? A few dozen?)
"Gentlemen, I would like to propose a new tax on the poeple to help fund what I like to call my giant 'laser'. This 'laser' will be used on all NASA buildings, destroying them one by one until the only space program in the world is MINE! I have all the telescopes! I have all the rocket fuel! If you want to send probes to Saturn you will have to pay me....one BILLION dollars! HAHAHAHAHHA!!!"
The Divine Creatrix in a Mortal Shell that stays Crunchy in Milk
The House Between - Original Sci-Fi Series
One the other hand, the rejection of a solar power source for Cassini meant what could have been a major push for solar power technology did not happen.
Bzzt, sorry, thank you for playing. NASA *wants* to use solar power. Solar power is cheap, easy and comes with no political headaches.
But, at Saturn, the solar flux is 1/90th that of earth's. AND-Cassini needs to broadcast data much farther than your typical geosat. If Cassini used the most efficient solar panels know at launch time (which, of course, is impossible, since it takes at least a couple of years to build/test a probe, it would have been much heavier-and thus, it couldn't be launched with the boosters then in use.
I am not making this statement as a blind advocate of solar power. But I do notice that a choice was made to spend a lot of money, officially on a basic science mission, in such a way that indirect benefits go to the military, and not to sustainable civilian uses.
No, money was spent on the only power source, know to man, that would be able to drive several instruments, record data, and transmit that data from the orbit of saturn. Furthermore, Pioneer 10 and Voyagers I and II are all RTG powered, and are still scientifically useful.
This isn't a nuclear/non nuclear or civilian/military question. This is a simple engineering exercise.
The ONLY power source capable of running the insturments aboard, and transmitting back that data, from a jovain orbit or farther, while still remaining light enough to be lauchable, is an RTG. Therefore, an RTG was used.
Ceci n'est pas une sig.
Not True! I remember seeing R.E.M. on one of the late night talk-shows just prior to the Galilleo launch. They were quite upset about the RTG safety issue and were advocating a protest at KSC.
ralph nader said 'utter and complete BS?'
--neil
This was a sociology professor? Not to be too big a jerk, but what does a sociology prof know about plutonium and satellites?
Hey, I HAVE a political science degree. You know what? If I EVER have to sit through another whiney group of navel-gazing experts discussing the ills of "society", I will retch. The only time I've ever heard more ill-informed opinions was the semester I majored in broadcast communications.
Call it sociology, political science, human studies, whatever, it's NOT real science. It's a bunch of research and studies. Pretending it is science is an insult to the fields of physics, mathematics, chemistry, etc.
Sorry for my rant, I've just suffered through way too many political speeches disguised as lectures.
You'd like that kind of half-knowlege? I can make a really good case that you already have a good supply of half-knowlege. The wrong half, that is.
Do you know what an ion is?
I'm smart enough to know what you actually meant with your above comment. It scares the hell out of me that you're not smart enough to say what you actually mean.
If tits were wings it'd be flying around.
You're wrong.
I'd rather risk my life by a scientific mishap than have things stay at status quo. If this civilization is to survive we *need* progress in physics and space exploration. We are not getting any, all money goes to stort-sighted business ventures. And then people object to even that little that IS being done. People like that will be the first to get a weapon and go on killing and looting if a world collapses in a few decades due to lack of energy or whatever. The same people who believe only *they* have any rights. People who tell you what color to use on your house, what plants to plant, and that no nudity is to be seen in theatres. Or don't give a shit about their economies exploiting other nations or even killing people just to keep their industries going.
I'd take scientific risk over human risk any time. I'm sick of people's "righteousness".
I guess it's all right! Let's pour more plutonium into the atmosphere! It doesn't hurt ANYONE...stupid hippies worried about such trivial things. Pfft!
Well, one of the reasons for the selection of Cape Canaveral (or whatever they're calling it these days) as a launch site was that rockets which had problems shortly after launch would end up in the Atlantic Ocean. It's not as though that part of Florida is a particularly nice place to live. And I know, I'm from Florida.
However, given that the Pu is encased in an extremely durable salt/ceramic mix, it's not nearly so dangerous as a hunk of raw Pu would be.
-- This and all my posts are in the public domain. I am a lawyer. I am not your lawyer, and this is not legal advice.
Does anybody know just how much plutonium the 26 men alluded to in the above article consumed? Just curious how that would compare to the amount we would have been exposed to had Cassini hit Earth...
... but a lot of people got scared, and probably still are. I still wonder why people som easily believe the negative scientific reports, but ignore the positive...
You are off by several orders of magnitude. The bare sphere critical mass of Pu-239 is about 10 kg.
There is about 5000 kg of Pu-239 in the environment as a result of fallout from nuclear testing.
RTGs use Pu-238, a plutonium isotope that is about 250x more active than Pu-239.
Mea navis aericumbens anguillis abundat
No-one is suggesting that we deliberately dump plutonium into the atmosphere. But the stupid hippies are continuing their long-lived tactic of putting out blatant sensationalist lies to get their way despite massive evidence to the contrary.
And many of us are getting fscking tired of being told what to do by idiots who are willing to lie about just about anything if it supports their cause. The last thirty or forty years since the hippies began their crusade have been an increasingly rapid fall into irrationality and chaos.
Fsck the "me generation"; the world will continue to get worse until they stop thinking only of themselves and we start following some rational policies rather than believing their crap.
And how much the stupid hippies have cost the US taxpayer in extra engineering time and payload mass required to add extra safety systems because of their idiotic claims.
Needs to be moderated up, IMO.
Reason #18 to post as an AC: Pulling "facts" out of your ass is encouraged.
The CERAMIC plutonium was divided up into small pieces encased in, I believe, uranium and graphite (or something), among other things. The idea is that, even if the probe were to have exploded or impacted the earth, the chunks of plutonium would not have burned up and neither would they have been in any way exposed in the end.
The chances of the Plutonium "catching fire and dispersing in the atmosphere" are nearly non-existant. Please do a little bit of research before you make assumptions like this and make AC's look worse than they already do.
72lbs of Plutonium isn't a lot.
You may think all scientists are arrogant, uncritical and blissfully ignorant when it comes to the things they do, but you should be willing to concede the possibility that the people with the PhD degrees in things like astrophysics and nuclear engineering might just know what they're doing. Mistakes happen, sure, but these guys are not stupid.
Agreed!
Why in the world did you post this as an AC? Post it as a user and be known. Let the credit flow to you. Let your comment's score be greater than zero.
Don't know why my reply to this disappeared, but luckily I saved it myself, so here it is again :
I think I'll just drop this. We're orders of magnitude apart insofar what we see as good science and engineering. To you good engineering is taking a risky endeavor and decreasing the risk as much as possible (an evolutionary approach.) To me good engineering seeks novel, risk free solutions (a revolutionary approach,) and is willing to be patient until the good solutions come.
As an example, rather than using plutonium to power Cassini's instruments, why not a flywheel based generator? There have been great advances in flywheel technology lately. In low-G and free fall environments, friction isn't a worry, so you'd get pretty decent efficiency. You ought to be able to torque the flywheel back up by catching a little angular momentum during a grav assist, if you make the approach just right.
It scares me to death to hear someone as apparently educated as you (and the others like you on this site) have no concept of long term ecological responsibility. It's enough for you that "you and I are alive right now," so therefore airborne dispersal of granulated heavy metals and radioactive material have no effect. DDT didn't get banned because humans started dropping off like flys in its presence. Lots and lots of major ecological damage was done before anyone started to do anything about it.
It's not about being a hippie or a luddite, it's just about acknowledging that the current dominant paradigm (to use a scary soc. word) of technological advancement has brought us some pretty dark returns. It's time to start learning from history. If we, as scientists (believe it or not, I am, in fact, a physicist - granted I'm a theorist) want to improve the reputation of scientific advancement, we have to start opening our eyes to the real world outside of the lab. Any risk is too much risk when it comes to endangering what little remains of the global ecosystem.
Life is a risk. You take your life in your hands every time you drive to work. (If you bike, take the bus, or walk you take even bigger risks.) A gasoline truck drove by your workplace today. It had a small, but non-zero risk of intense fire or explosion. Pesticides, herbicides, and serious industrial chemicals are shipped by truck and rail every day. There are risks associated with all of this.
"The cowards never started and the weaklings died along the way." (Please direct all Politically Correct flames to the nearest propane tank. ;-) There's dern little risk-free anything in this life. Get used to it. Work with it. Make it work for you. . . . If you just "wait" for revolutionary advances to come to you, they'll never happen. Somebody has to make them happen. Somebody willing to try something new, and possibly a bit dangerous.
And yes, I'm still going to minimize those risks to the extent possible and practical, even if you don't find that esthetically pleasing.
As an example, rather than using plutonium to power Cassini's instruments, why not a flywheel based generator? There have been great advances in flywheel technology lately. In low-G and free fall environments, friction isn't a worry, so you'd get pretty decent efficiency. You ought to be able to torque the flywheel back up by catching a little angular momentum during a grav assist, if you make the approach just right.
Ingenious, but there are a few problems:
- Flywheels don't generate power. They just store energy. On a mission that will last 11 years or more, a reliable, long term source of power is needed.
- Cassini's last gravity assist is at Jupiter. It won't reach Saturn until years later. What provides minimal housekeeping power (and heat) for that time?
- Off hand, I really doubt you can pick up any significant power without a much steeper gravity gradient than either Jupiter or Saturn has (to say nothing of Earth). I suspect it would take a close approach to a neutron star or a black hole to spin up your flywheel. (And no, I'm not going to pull out MTW's Gravitation and try to remember enough calculus to use it without serious consulting money. 8-)
You'd do better to look into electrodynamic tethers. In the presence of a strong planetary magnetic field, they can turn an orbiter's kinetic energy into electricity and vice versa.Cool? Yes. Ready to use in the outer Solar System? Definitely not.
We've had trouble making tethers work in the two Space Shuttle missions that tried them. The SEDS folks have had better luck with their regular and electrodynamic tethers, possibly because they started small and built up. Besides, the conditions dictated by the Cassini mission wouldn't be right for an ED tether.
It scares me to death to hear someone as apparently educated as you (and the others like you on this site) have no concept of long term ecological responsibility. It's enough for you that "you and I are alive right now," so therefore airborne dispersal of granulated heavy metals and radioactive material have no effect. DDT didn't get banned because humans started dropping off like flys in its presence. Lots and lots of major ecological damage was done before anyone started to do anything about it.
You're still missing my point: The claims that "Pu is the most toxic substance in the world" are bogus, wrong, and incorrect. If those claims were true, we should have been dead many times over. The DoE admits to something like 4.5 tons of Pu-239 was released by USA nuclear bomb testing. That's only the Pu. How about the radio-activated bomb casings, dirt, and other debris? How about the U-235? How about the vastly more deadly fission products? What about the Soviet and French bomb tests? Even more radio-crap kicked into the stratosphere.
When I say "we're still alive" that's an existence proof that the claims of the anti-Cassini groups are flat out wrong. It is not an invitation to dance about the world scattering PuO2 around. Sheesh!
Tell you what -- let's consider Teller's bet. If you still believe that Plutonium is the most lethal substance on Earth, then I'll swallow 1 milligram of Ir-coated Pu-238 dioxide, if you first swallow 1 milligram of botulism toxin. Then we'll see which is the most poisonous stuff around. You'll die in frothing agony within minutes while I might get cancer 20 years from now. Maybe. (Even that is unlikely thanks to the iridium coating -- but since Cassini is using Ir, so can I. 8-)
Furthermore, Cassini wasn't going to crash and didn't crash. If it had, I was willing to bet that the RTG designers had done their job right. (Didn't you watch the tapes of the RTG testing?) Even if they hadn't, we're back to the "deadly Pu" myth again.
You're "scared" that I and others aren't "ecologically responsible" enough to suit you. Well, sorry. I'm not going to stop thinking about life's risks and start emoting about them (i.e. become a neo-Luddite). And, I can't help your fears, other than to point out where they are unfounded and to hope that you will conquer them.
It's not about being a hippie or a luddite, it's just about acknowledging that the current dominant paradigm (to use a scary soc. word) of technological advancement has brought us some pretty dark returns. It's time to start learning from history. If we, as scientists (believe it or not, I am, in fact, a physicist - granted I'm a theorist) want to improve the reputation of scientific advancement, we have to start opening our eyes to the real world outside of the lab. Any risk is too much risk when it comes to endangering what little remains of the global ecosystem.
Well, hell. If you're a theoretical physicist, then you can break out Misner, Thorne, and Wheeler to find out how feasible your flywheel idea is. Remember that you're limited to, at most, one metric ton. (Even that is generous; the RTGs don't weigh that much.) And, you've got to fit the resulting flywheel and it's housing into the Shuttle's cargo bay. Oh, and make sure that this enormous spinning flywheel doesn't make it impossible to maneuver the probe. C'mon -- I dares ya! I double dares ya! ;-)
Also, get off your philosophical high horse. Species have been made extinct with nothing more than sticks and stones. (E.g. the hypothesized extinction of the America's large mammals (mammoth, etc) by human hunting after the last Ice Age, and definitely the Dodo, killed by sailors armed with clubs.) Consider human misery caused by the Khmer Rouge with relatively little technology and a whole lot of savagery.
In other words, science isn't the problem; it's what you do with it. There's no tool in existence that can't be used for good or for evil. Any increase in power comes with an increase in responsibility. All your talk about "dark returns" and "want to improve the reputation of scientific achievement" strikes me as a bit too Woody Allen-esque for my tastes.
"Any risk is too much risk ...." Feldgercarb! If you truly believe that, then you'd better go out and commit suicide, because your very existence is a slight risk to the global ecosystem. (Sure, it's an incredibly slight risk, but you're the one claiming "any risk is too much".) Remember the the Oklo natural nuclear reactor? It fired up in Africa (references not at hand) a long time ago, and operated sporadically for millions of years. No containment dome. No nothing -- just an unusually rich bed of uranium ore moderated by the soil and ground water. The planet survived that. It will survive us.
That's not to say that we can strew our garbage wherever we like. The ancient proverb, "Do not throw rocks in the well you drink from" still applies. But, the whole point about intelligent life is that it makes new resources and new ecological niches possible. If our species has a "purpose," then it may well be to bring life to lifeless planets. It is not to hide in the basement because we're afraid to do anything at all.
"You've crossed my Line of Death!" "What? No! Where is it?" "Here in the fine print...."
Any kinetic energy the earth loses this way could easily be replenished by harvesting it from other planets. Simply speed up some probes using the gravity assist of other planets, and then let the probe crash into the earth at the appropriate angle.
The plutonium in there is already in the form of oxide. It can't burn up.
I think you have missed the point here. No one with a firm grip on reality would ever seriously make the claim that "nothing could possibly go wrong." Every single thing we do in daily life is fraught with some level of risk. (Contrast the dozen or so people who have lost their lives in the space program with the hundreds of thousands who die every year in car accidents.
What can reasonably be said about the Cassini mission is that the level of risk was *extremely* small. The fact that NASA took safety measures with the mission is what helped to make that risk so small. If they were just lanching a pile of unshielded plutonium on top of an untested rocket booster, the risk would be huge. NASA takes measures to reduce that risk as much as possible. The relevant question, therefore, is not how risky the mission is inherently without any extra precautions. The relevant question is how much risk is there once you factor in all of the elaborate safety measures. The answer is very little, a fact corroborated in hindsight by the uneventful flyby.
Clearly you place no importance on the exploration of space. Many people would disagree strongly. Some even feel that exploration and colonization of space is the only hope for the long term survival of humanity. It is the only possible way that we can survive a truly global catastrophe (e.g., large asteroid impact, global thermonuclear war, global environmental disaster, etc.)
If you are not interested in that long term view, then consider the short term spinoff benefits. The goals of the Apollo project were mostly about national prestige and the urge to explore for its own sake, but the spinoffs of the technology developed to reach the moon have reached into every aspect of our lives. You claim to be "a total techno-head." Consider then for a moment that nearly every device/technology that you value today had its origins in the pure research of the space program.
A final argument in favor of space exploration in general and planetary science in particular is that understanding the climates and "geologies" of other worlds helps us to better understand (and hence protect) the Earth's climate. Do you realize that the whole idea of a planetary "greenhouse effect" came from the study of Venus?
To sum up, the "end" is not trivial. Far from it. And the risk is as low as can be achieved, far lower than the risks most people accept in their lives every day.
Yeah, Nuclear is really bad compared to spewing thousands of tons of crap into the atmosphere when we burn coal. Attitudes like yours killed the funding for fast breeders and other good technology that could/would make nuclear power safer than cheese. Thanks.
Makes you wonder how all those safety measures affect the efficiency of the thing.
there was this book I read some time ago that said how the US chose light water nuclear reactors as the standard instead of another design that was so inherently stable that it would not melt down even if the control rods were taken out of the reactor and used as kiddie toys.
... of GE)
the author was one of the scientists working on nuclear power. he was employed by General Atomics. (strangely enough, an ex-division
the reason for the choice was political rather than scientific/technical. (the scientists were all for the safer reactor)
can anyone confirm this or do I have to go have another drink?
Between 1945 and 1959, the United States conducted some 600 above-ground nuclear tests, utilizing some 22,000 pounds of plutonium in the process. A nuclear explosion is not a very efficient process; only between 8 and 12% of the fuel in the bomb is actually converted in the process. The rest is vaporized by the explosion and cast into the atmosphere, to settle out downwind as fallout.
That means that some 9,000 pounds of metallic plutonium has been circulating in our atmosphere for some decades now. We apparently survived, although how well is a matter of debate.
The 72 pounds of ceramic plutonium on board Cassini is a pittance in comparison and is chemically much harder to incorporate into the body than the metallic form.
Let's put it this way. If I ate a teaspoon of what Cassini is carrying, I'd stand a slightly elevated chance of colon cancer some twenty years down the line. If, at the same time, you ate a teaspoon of a completely legal substance, nicotine, you'd be dead in minutes of a heart attack.
Elf Sternberg
If you're so smart, why aren't you naked?
too bad there aren't 8 billion people on earth.
more_fun_flame_mode(on); // I enjoy debate. I dont take it personally.
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If I remember what I learned in Chemistry a few years ago, the critical mass of plutonium is about 2,000 pounds.. Meaning, in any warhead, there must be at least 2,000 pounds of high-grade plutonium to smash together in order for an explosion to occur.
2,000 pounds. Compared to 75.
Now, multiply that 2000 figure by the number of plutonium warheads that were tested out here in the desert, and out in the pacific for the past 40 years. Compare that figure against the 75 pound nuclear payload aboard the Cassini. The difference between the "threat" of Cassini and what _has already been released into the atmosphere_ is so laughably huge that it doesnt even warrant a concern on our part. You'de be more likely to have your life disrupted by tripping over a crease in the sidewalk than you would have it disrupted by Cassini coming back down to earth.
You need neither be a rocket scientist, nor a mathematician to figure out that all the whining over the Cassini probe is nothing more than radical hippy whiners who think we should make rockets out of hemp and fuel them with manure. The whinings occasionally get picked up by the media, which is why you're hearing about it here.
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Bowie J. Poag
Bowie J. Poag
Swallowed plutonium is fairly harmless. It's not water-soluble or fat-soluble, so it passes through your intestines into the toilet. Only a thin layer of cells in the digestive tract gets exposed to alpha rays, and those cells are constantly dying and falling off anyway, just like skin. BUT if you inhale a microscopic amount of plutonium dust, it will get stuck in the tiny air sacs of your lungs. For the rest of your life, the living tissues of your lung will receive a steady dose of alpha radiation.
It doesn't say in the article. But note that only 4 of these men died when 10 would be expected to die from any random sample of men. Thus either 1) Plutonium make people live longer or 2) This sample is exceptional. It also doesn't say whether or not the men were sick or what have you, or whether any or all of these men actually had cancer, excepting the one who died of it (they might all have had cancer, but not yet died, and plutonium exposure may or may not have been the cause). As the article suggests, this is all probably just a statistical abberation, from which no conclusions can be drawn. It's a pretty lousy study to use as proof of a point. Couldn't they come up with a better one?
Yah only the military has ever benifated from space research. They are the only ones with access to them new fangled computers. And that teflon coating on their pans, why should the be the only ones who get stick proof pans? And those suits that fire-men wear to keep them safe inside burning buildings, it's not like their a direct off shoot of the space program or anything. In the future I sugest that you think a bit before you post. The space program has had countless benifates for man kind. Just because they don't send homer simpson into space doesn't mean he hasn't benifated from it.
BTW, from what I understand NASA rejected solar power because at the time it was not viable, and on a long journey you have a huge chance of those panels being destroyed by space debris. Don't you think NASA would rather use solar power? Which do you think is cheaper, 75 pounds of plutonium, or sun light?
-matt
*Sigh*. People, this is a troll, plain and simple. You can't start out by calling people names like "whiners" and "panickers", then complain that people don't pay attention to real science, then present some really poor science (what exactly is an atom supposed to degrade into anyway? Where did those 400,000-500,000 numbers come from anyway?) unless you're trolling for angry replies.
As a side note, why did this troll get 2 points and an "Informative" label?
The plutonium is encased in a very thermally-hard material that NASA has tested the *!&#@$ out of to make sure that upon accidental re-entry, the plutonium wouldn't burn up. That way they could recover it and not cause the so-called 8 billion deaths of lung cancer.
I suspect that we're kindof safe on this one. Newton's laws have a pretty strong track record when it comes to space travel... ;) Anyone know if Cassini has a control burn near Earth? Although, if you want to get paranoid. Chances are that there's a couple of US and Russian military satelites with nuclear power plants up there... Tom
Galilleo had two close passes with the Earth in '90 and '92 (the '90 was closer, 1000 km no ?) It was a lot sicker than Cassini, too, with the failure in the main antenna. Didn't hear a peep, then. Why ? Because no-one had an agenda to push back then. Now they do, and they go "Plutonium! Nasty! Be Scared! Cancer! They say it can't happen!!!!!!" and hope that no-one bothers checking up on the facts. (Oh, and the fact that most of the US was keeping an eye on that little tussle in Iraq.) Remember, the people who launch these things have friends and families here on earth, and, also, a mistake at this point means no more funding for the next 5 or 7 years.
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Yeesh. All this whining makes me wonder why people aren't impressed with heavy-duty science anymore. Instead of the thrill of discovery, people would rather occupy their time panicking and whining about a 75 pound lump of "angry rock".
Reminds me of that episode in All In The Family where Gloria complains to Archie about how many people die every year by guns. Archie quips back, "Well little girl, would you be happier if they got pushed out of windows?"
Lets suppose for a moment that 75 pounds of plutonium *did* come hurtling through our atmosphere. First and foremost, it would probably be so badly degraded upon re-entry that it wouldnt matter *what* it was. You could send a damn dump truck full of boubonic plague through the Earth's atmosphere, it would probably disintegrate before ever reaching the ground. The earth is continually bombarbed by fairly large chucks of threatening debris 24 hours a day, 7 days a week, 365 days a year. Its been this way for millions, if not billions of years. There's a _reason_ why we arent living in a sea of craters, kids.
Besides.. Earth has already seen far worse man-made ecological disasters over the past 200 years than 75 pounds of plutonium could ever cause.
The Industrial Revolution, Hiroshima, Nagasaki, thousands of Cold War nuclear tests , Love Canal, Three Mile Island, Chernobyl, The Gulf War, just to name a few... I'd be willing to bet that if you took every single person who experienced irreversible physical illness as a result of these catastrophies, you could probably arrive at a figure of around 400,000 to 500,000 people grand total. And as tragic as those numbers are, they amount to less than one one-thousandth of a percent of Earth's human population. 75 pounds of plutonium, even *if* it came back to earth, would not reduce us to the level of a bunch of custard-eating Teletubbies living below ground for the next 10,000 years. Besides, i'd trust an engineer over a hippy, wouldnt you?
In other words, the 90's are over. We can all put down out guitars and quit whining now. Putting limits on what science can investigate is far more dangerous than sending a silly little spacecraft out for a spin.
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wildly_inflammatory_editorial_mode(off);
Bowie J. Poag
Bowie J. Poag
Most gravity assists have control/acceleration burns . At their closest approach the craft can gain the most advantage to burning some of it's fuel . The math is a little complx but basically ... it is possible that it is most efficient to burn once on the first gravity boost . The guys at JPL are pretty good ( form what I hear ) at figuring out exactly what is the most efficient .
the craft falls with the fuel but does not carry that fuel back up .
Although
Squireson@bigfoot.com
Let us start a compaign against gravity assists and let us model it after the campaign against nuclear fuel onboard spacecraft .
This would be high satire .
squireson@bigfoot.com
Sure, orbital mechanics is absolutely predictable... but the risk involves collision with a piece of space junk floating around in earth orbit... there's lots of nuts and bolts and paint chips up there.
It's better than that - the "crap" you get from burning coal actually contains significant amounts of radioactive material (mainly Thorium, I think).
That was the risk for the fly-by, not the launch. I personally don't have much faith in those estimates but the risks during launch are much highier. The contents if exposed would of ruined the launch area for thousands of years (plutonium has a terribly long half-life) and don't bet on anyone clearing up that stuff (basically clearing up every micron particle would be unrealistic). I love science and space exploration but this is just complete lunacy.
They seem to have no idea that radioactivity is all around us all the time... and most of the time we (Humans, Inc) get along just fine with it.
These people have obviously never thought about why a Geiger counter goes off around a piece of granite....
They probably would totally freak out if they realized that depleted Uranium is in virtually every Jumbo jet flying today. (Used as a counterweight on the wing control surfaces to minimize flutter because they needed a very dense counterweight that could fit within the wing contour plus our government was apparently selling tons of the stuff at discount prices)
Not to mention I have a lot of respect for the boys at JPL... when you consider what they could make by going into industry, you have to admire the dedication.
--Rob
JPL's Number One Fan
--Rob
The development of civilian plutonium-based space missions helps to support a nuclear industry based on the plutonium cycle.
A major problem right now is how to get rid of plutonium from old nuclear weapons. Assuming it's the correct isotope, shooting it into deep space saves it from having to be buried in someone's back yard. As another person mentioned, the sun's just too dim in the outer solar system.
I'm a Canadian, and when I was a kid a Russian satellite came down in the arctic, and spread radioactive contamination over a good chunk of land. This satellite DID NOT have the kind of safety that Cassini has, and even though a few Caribou may still glow in the dark, the world did not end. I'm sure that this incident made Cassini even safer, since contrary to popular belief, scientists are quite likely to learn from their mistakes, and the mistakes of others.
For my money, as long as more than 1% of the world's population smokes, drinks, or eats hamburger, a 1-in-N-billion chance of the worst-case Cassini scenario is a negligible risk. I WANT to see pictures of Saturn. I'd wager that all the environmental impact reports that had to be done on Cassini did more damage to the planet (e.g. by dioxins from bleaching the paper they're printed on) than the probe itself ever could have.
But, at Saturn, the solar flux is 1/90th that of earth's. AND-Cassini needs to broadcast data much farther than your typical geosat. If Cassini used the most efficient solar panels know at launch time (which, of course, is impossible, since it takes at least a couple of years to build/test a probe, it would have been much heavier-and thus, it couldn't be launched with the boosters then in use.
Or for that matter, boosters that are planned to come on-line in the next ten years. Cassini is, if my memory serves me correctly, the heaviest deep space probe yet. Any heavier and we could not have launched it.
All of the replies to my post have been on the order of "there are much worse mutagens already in the environment, so adding a tiny bit more isn't any big deal."
But every little bit raises the rate of birth defects (or cancer, etc etc etc), so I stand by my question-- are YOU willing to have a child with a birth defect (or cancer) in order to save a few million on whatever tech project is under question?
I don't believe any sane person would be.
Wow, I'm glad the government doesn't have to ask my permission to risk my life. That'd be so inconvenient!
yeah, but most people have 2 lungs right? Typically, you only get one cancerous lung.
If I have cancer in both lungs doesn't that mean I have two cases of lung cancer?
The next titan launch did explode, but it was the older titan rocket with known problems. The titan that launched Cassini enjoys a perfect launch record.
Enough of the FUD already.
AMEN!
Bowie J. Poag
Bowie J. Poag
Cassini DID crash into the Earth, but NASA's spokesfolks aren't willing to admit this.
Why, oh why didn't we listen to Ralph Nader and his friends? We're all gonna die!
It's true though. And since we're talking about a planet-wide issue, should the US government have to get the permission of every one of the approx. 6 billion people that live here? Does this apply to private entities (individuals and corporations) which are conducting risky work?
The airplane argument I mentioned earlier is this: I hate to fly. I'm absolutely terrified of flying. Really. So I don't fly unless I absolutely have to; it's a stressful experience that I would be all too happy to not have to deal with. However, given that I am strongly concerned about planes dropping out of the sky on a more or less random basis, why should I be put at risk of having planes that I'm not even in falling on _me_? There's no reason for pilots et al to risk my safety by flying planes at all, even if I'm on the ground.
The answer of course, is that if something is not immediately dangerous and extremely risky, it can be done without having to get approval from the people who may be effected. The Cassini probe was determined to not be likely to endanger people, and thus, it was approved. Had it not been considered to be sufficiently safe, it would never have gone ahead at all.
-- This and all my posts are in the public domain. I am a lawyer. I am not your lawyer, and this is not legal advice.
Plutonium! You mean this sucker is nuclear?
...
No no no. It's electrical. But I needed a nuclear reaction to generate the 1.21 Gw of electricity
When this baby hits 88 MPH, you're gonna see some serious shit.
I stand by my question-- are YOU willing to have a child with a birth defect (or cancer) in order to save a few million on whatever tech project is under question?
Are YOU willing to become a quadripalegic in order to save a few hours getting around town? Do you drive/ride in a car, or walk everywhere? (It's not clear you're very safe as a pedestrian either, maybe you should just stay home and worry about meteors coming through the roof). Everything in life has a risk associated with it. Some (like Cassini's), are so low as to be laughable.
So, yes, I'm willing to take this risk for the advancement to science it provides. Just about everything I do in my life puts me in far greater danger than this space probe does.
Do you think NASA, the rest of the government, and the nuclear power industry are any more honest than Ralph Nader et al.? NASA has lied plenty in the past. If they say the odds against the probe crashing are "a million to one", they're pulling the number out of their ass! They also said the problem of a certain takeoff (was it Cassini?) were a million to one. We've had a lot less than a million launches, and a lot more than one crash.
NASA, the DoD, the defense industry, and the nuclear industry all have very direct, self-interested reasons why they want us to think this is safe-- they get money and power. (Ralph Nader et al., isn't getting rich here; he's a favorite target of liberal-bashers because he's a "consumer advocate", but ya know, you're one of the people he's trying to help. You do know he promotes Linux against Microsoft, right?)
They're lying, people! I mean, I want to promote space travel too, but don't be a sucker because they can count on all geeks blindly supporting NASA in everything they do. We are being used.
Really, we should be a little more critically-thinking than this. We should know better. I'm surprised that I'm the first slashdotter in over a hundred comments that has raised these points.
But every little bit raises the rate of birth defects (or cancer, etc etc etc), so I stand by my question-- are YOU willing to have a child with a birth defect (or cancer) in order to save a few million on whatever tech project is under question?
Your argument is flawed because you're setting up a false choice. If you put up a realistic description the risk vs. reward you might have something to discuss.
I think I'll always have fond memories of the Cassini mission. Back a couple of years ago when debates were running rampant before NASA launched it, I got involved in a really enjoyable debate with some Sociology students at school.
The teacher in that class, who IMHO would ban himself if he realized that upon death he'll undergo radioactive decay, was always saying to his students 'Subvert the dominant paridigm.' And whenever he told his students to jump, every single one of the bozos asked how high.
I bashed through their anti-Cassini arguments like a knife through vaporized butter. My shining moment was when one of them complimented me for having subverted the dominant paridigm of the class. That was cool.
The moral is: stay far away from Gordy Fellman.
-- This and all my posts are in the public domain. I am a lawyer. I am not your lawyer, and this is not legal advice.
Your arguements suck . I am not pointing out that you are wrong only that you are right for the wrong reasons .
The casings were designed to survive a ctastrophic explsion upon launch . Nobody points this out .
Reentry is virtually impossible .
If Nasa misses the approach point by a few meters they pour over records for weeks trying to figure out what went wrong .
If it is going to miss by more than that they know about it weeks or months in advance and can fire onboard rockets to adjust .
If they can't fire onboard rockets they can rockets at the thing .
Cassini will get to jupiter within several miles of their projected course . Newtons laws still work very very well .
No safety threat . Not at launch , not ever .
Nope. I'm first. You're always first now I get to be first. If I don't get to be first then I'm going to tell.
For all you bastards who have "newest first" set.
Yes, it would cause eight billion cases of lung cancer. If.
If, we ground it up into a fine powder, then managed to distribute it to the world's Evil Organizations, then managed to coerce everyone into lining up for their turn at the inhaler.
Or, if we could manage to get several thousand blimps to fly over most of the world's populated areas, somehow dusting the atmosphere with the said powder.
If.
That's assuming it wouldn't completely burn up upon entering the atmosphere.
But, it's only eight billion cases after all. We have six billion people right now. We'd better get a-breeding so some people survive.
the world just reached 6 billion people
It's interesting how pro-Cassini people are here..
I guess after the fact, that's pretty safe position..
Yes, orbits works good, physics work good, but computers work bad, people make mistakes, shit happens..
It all worked fine this time, and next time, and so on, until time number five thousand there is bug, a burn jams and pow... You dom't get alot of pows before things start to get pretty bad down here at Humans Inc..
The money on Cassini is nothing compaired to say, Apollo 13, and look what happened there.. Things break, it happens..
Of course something like Cassini is a million times safer and more sane then all those atomic weapons and power plants, but still just not a good idea..
This stuff is too dangerous, find another way...
Just say no to nuclear power, any kind, any where.. If you can mine the resources outside of earth orbit, and use them there, fine, but keep that shit away from my(our) bioshphere.. It's about as safe as powering equiment with anthrax..
Cassini carried about 72 lb of Plutonium. You make it sound like an everyday occurrence, but in fact that is far more than almost any other spacecraft has yet carried. The potential disaster may have arose if after an accidental re-entry, the Plutonium would have caught fire and dispersed in the atmosphere. Winds would have scattered it everywhere. Skeptics and military industrial people don't understand that aiming the equivalent of a nuclear bomb at Gaia is unacceptable. For a speedier trip to Saturn the space cadets risked the general health life on Earth. It is to my great relief that this mission succeeded, unlike a lot of other space missions. The bravado expressed on this news group indicates a high degree of scientific arrogance inappropriate for critical and skeptical thinkers, especially when one considers the many rocket disasters of late, the Challenger disaster, the many Apollo failures, and the reliance on Europeans for many critical components on board the craft. Thank you. Have a nice day.
Does anyone remember the test that BNFL did a few years ago - they put a waste transport vessel over some railway tracks and crashed an Intercity 125 loco at cruising speed into it.
The train came off worse.
Even if Cassini had totalled on the launch pad, there would have been no mass contamination of Florida becuase the core was designed to hold together in such an event.
There's a vidcap of the train crash kicking around the net somewhere. Must go and find it.
james
Absit Invidia
Some of the commments in these threads sound like they come from the same people who lapped it up when the military kept telling us how fanastically Patriots were working in the Gulf War. That was all the anti-anti-war propaganda the government needed to start, these guys picked it up from there, so happy to wave this banner of success in the faces of people who had doubts about the war. Nothing makes people like that feel more secure about themselves then to believe the great machine that they're a happy little cog in runs as well as everybody promised; that real life does work exactly like the sample problems in their textbooks; that there is never any need to step back and wonder what life might look like if a few "truths" were less than true.
Technically, of course, you're right - the chances of a collision with a piece of space junk large enough to cause a signifigant course alteration are very slim. Nonetheless, the chance of a disaster from which our species would not recover exists, and should be addressed. The point of the protests is not to stop scientific progression, but to put a halt to the cheapening of good science by the get-rich-quick mentality that's been seeping in in the latter half of this century. The aim of science, above all, is to improve our lives, not endanger them. Nonetheless, the notion of "acceptable risk" has become common parlance - it does not bother anyone to put money one side of an equation and human lives on the other.
"But the risk is so insignifigant!" you cry. Sure, for now. The problem comes with scalablity. If we let ourselves get used to cheap, brute force crutches like plutonium fueled vehicles, we get stuck with them - they become the standard, not the bonus. So when someone wants to do something that is more innovative and safe, they'll hear "Sorry, that is not economically viable." In the meanwhile, longer missions with larger vehicles are planned: "Shoot boys, guess we'll have to shove some more plutonium in that dad' burned thang. They didn't complain about 75 pounds, how can they complain about 150, it's only 75 more..." Bad scalability is at the source of virtually every environmental problem we have, it's almost the definition of an environmental problem. We're good enough and smart enough to create technologies that leave no footprints, if we just give ourselves the chance.
What do we lose if we wait for a real solution to the propulsion problem - a few years maybe? I can wait a few years in order not to risk the lives of the vast majority of people on this planet who couldn't give a damn about space research. What gives people who like technology the right to constantly risk the lives of those who don't? Sure, we satisfy ourselves with glowing descriptions of how "acceptable" the risks our of our endeavors, but we don't have to flip too many pages of a history book to find case after case of people and ecosystems who got completely screwed by technological endeavors that had nothing to do with them and that will never benefit them.
If wanting real science, not corporate bullshite makes me a hippy, than send me my Freedom Rock record. In the meanwhile, I'll remain slightly annoyed that the people with the plutonium don't seem to mind spreading it around. (I don't know if you noticed it or not, but all the radioactive material we spread around just MIGHT be part of the reason why so many people seem to be getting cancer these days... bah, but what's a few more pounds here and a few more pounds there, right?)
I've noticed a strong correlation between anti-Cassini sentiment and, well, to be blunt, ignorance, but I didn't expect to find so much of it on /. The anti-Cassini FUDmongers are *counting* on your ignorance. Fight it! Talk of toxicity, birth defects, dosages for every man woman and child on Earth, and even expressing any appreciable risk of collision from a gravity assist whatsoever, all reveal that the person doesn't know what he or she is talking about. Plutonium *can* cause lung cancer, but the real facts are *no one knows* how risky it is, quantitatively. Public reaction has prevented any serious research into Pt toxicity since the early '60s. Anyone who quotes toxicity or fatality numbers as a result of a Cassini crash scenario is pulling them straight outta their ass. RTGs were chosen as the electrical power source after consideration of *all* the relevant costs and risks: economic, technical, AND environmental. This is SOP. Every option is identified, and evaluated by performance vs. cost and risk. The winner of this contest (in the case of Cassini) was RTGs. If there were any real risk to human health or life, they would have chosen some other energy source. (Note that "real" risk is not the same as "conceivable" risk. You have to stop somewhere.) Now compare that approach to the one used by the FUDmongers. Just like many other reactionary groups, they start with the assumption that "plutonium = bad." Period. No arguments. No challenging the assumption. There are, by their definition, no acceptable ways to make it safe to use - don't even try. Any attempt to reform the object of their FUDmongering is met with instant, vicious, irrational fusillades of vitriol and flying spittle. Causes like this are only popular with the ignorant... Please, fellow /.ers, before you take sides on the next technical issue like this, recognize when you are under-informed, and study it first. *Then* choose your side. Real socially responsible people aren't afraid to say "Gee - I don't know. Let me look into that."
I can see the fnords!
Hehehehehe. And what about your post, silly boy? Where's *your* content? :)
Read my stuff.
2) If the Cassini rocket had blown up on takeoff like the very next Titan launched did, would you have taken your pregnant wife to the beach in South Florida?
The replies here are just techno-macho insanity. It makes me very sad for the hacker community.
...it wouldn't have been an environmental disaster anyway.
The plutonium is in the form of pellets. So unless you ground the pellets into dust, no "disaster". Its an alpha source, so a couple inches of air would stop any emissions.
Oh well, guess emotional scaremongering wins out over scientific fact every time.
As for rocket malfunction on launch, then the spacecraft would fall back on top of the Space center, or just drop into the sea just off the coast, where it would be easily retreivable.
Leo
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I've got green eyes, red hair, and I'm left handed. A hundred years ago, I'd have been considered in league with the De