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Cassini's Space Odyssey To Saturn

samzenpus posted about 3 months ago | from the mission-of-the-rings dept.

Space 45

An anonymous reader writes in with this look at the amazingly successful Cassini mission and the discoveries it has made. Scientists says Cassini is helping them understand how our solar system developed. Of the astronomically profound discoveries it's made over a decade of circling, the startling hint this April of a new moon being formed in the rings of Saturn is merely the latest. Indeed, the spacecraft Cassini — which inserted itself into orbit around the giant gas planet in July, 2004 — has transmitted imagery and sensory data back to Earth that has given us a new understanding of our bejewelled neighbour three doors down. "It's one of the most successful (space) missions probably ever," says University of Toronto astrophysicist Hanno Rein, whose own work has been significantly informed by the tiny craft's output.

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Happy Sunday from The Golden Girls! (0, Offtopic)

Anonymous Coward | about 3 months ago | (#47395169)

Thank you for being a friend
Traveled down the road and back again
Your heart is true, you're a pal and a cosmonaut.

And if you threw a party
Invited everyone you knew
You would see the biggest gift would be from me
And the card attached would say, thank you for being a friend.

Fear Mongers Didn't Want to Let Cassini Fly (4, Insightful)

Anonymous Coward | about 3 months ago | (#47395193)

Anybody remember all the whiners trying to stop the launch of Cassini because it's powered by plutonium?

Re:Fear Mongers Didn't Want to Let Cassini Fly (1)

Trepidity (597) | about 3 months ago | (#47395235)

I do [motherjones.com] :

It sounds a lot like the plot of a sci-fi blockbuster: A deep-space probe powered by a highly radioactive substance could wipe out humankind.

Re:Fear Mongers Didn't Want to Let Cassini Fly (1)

mbone (558574) | about 3 months ago | (#47395347)

That is one advantage of using the SLS for the Europa-clipper - it would be a Hohmann trajectory, with no subsequent Earth-flybys to get people anxious.

Re:Fear Mongers Didn't Want to Let Cassini Fly (4, Insightful)

rogoshen1 (2922505) | about 3 months ago | (#47395349)

Holy shit. reading the linked article:

But critics disagree with NASA's calculations. "Give me a break. They're making these numbers up," says Michio Kaku, a professor of nuclear physics at the City University of New York, adding that by his calculations of NASA's own accident scenario, some 200,000 people could die if Cassini crashed in an urban area. "This is a science experiment, and we are the guinea pigs."

I would not have expected him to have that kind of outlook.

Re:Fear Mongers Didn't Want to Let Cassini Fly (1)

Trepidity (597) | about 3 months ago | (#47395569)

Huh, I had overlooked the name when reading the article, just read right though to "some physics prof thinks NASA is wrong and it's actually super-dangerous". Didn't realize it was Michio Kaku, which is indeed surprising.

Re:Fear Mongers Didn't Want to Let Cassini Fly (3, Interesting)

Gareth Iwan Fairclough (2831535) | about 3 months ago | (#47395787)

Huh, I had overlooked the name when reading the article, just read right though to "some physics prof thinks NASA is wrong and it's actually super-dangerous". Didn't realize it was Michio Kaku, which is indeed surprising.

It wasn't surprising to me in all honesty. The man is very intelligent yes, but when it comes to nuclear energy he simply will not look at the facts. I've read a few books by him and every single one has had some mention of nuclear energy in it and all of those mentions could be paraphrased as "Nuclear fission reactors are bad and you would be bad for thinking they could ever possibly be good". In fact, I recall that he dedicated an entire book to that very message.

Re:Fear Mongers Didn't Want to Let Cassini Fly (4, Interesting)

arth1 (260657) | about 3 months ago | (#47396071)

Michio Kaku is very intelligent, but he's also an attention whore of the first order.
Too often, that seems to trump reason and restraint.

Re:Fear Mongers Didn't Want to Let Cassini Fly (2)

demachina (71715) | about 3 months ago | (#47396265)

He also seems to spend most of his time enriching himself with bad pop science books and TV appearances. Maybe he did some useful science early in life but at this point he is NOT a scientist to admire or aspire to be.

Re:Fear Mongers Didn't Want to Let Cassini Fly (1)

nadaou (535365) | about 3 months ago | (#47397633)

nonetheless and ignoring possible character flaws, does his calculation hold water? that's the only thing I'm interested in.

Re:Fear Mongers Didn't Want to Let Cassini Fly (1)

Gareth Iwan Fairclough (2831535) | about 3 months ago | (#47397829)

nonetheless and ignoring possible character flaws, does his calculation hold water? that's the only thing I'm interested in.

Considering that there was only 33KG or so of plutonium 238 in its RTG, I would say "hell no, no no no no no, never-in-a-million-years-absolutely-not" and I haven't even seen MKs calculations. That amount, even if the RTG broke open and scattered the Pu238 over a city, would be far to dilute to do any harm at all.

Re:Fear Mongers Didn't Want to Let Cassini Fly (1)

prgrmr (568806) | about 3 months ago | (#47399933)

It's more complex than that: Cassini has 3 RTGs, plus a dozen or so pellets in the Huygens probe to keep its instruments from completely freezing during the 7 year trip to Saturn. The ultimate "doomsday" scenario would have to have the entire spacecraft vaporizing less than a mile over a major metropolitan area, scattering plutonium dust as it goes. However, I would be much more concerned if it exploded over a fresh-water lake or reservoir, tainting the water supply. Given that 70% of the Earth's surface is covered by water, an ocean landing would have been much more likely had it crashed. The biggest risk was the launch: 1 in 40 rocket launches blow-up on the pad or before maximum velocity is reached.

Re:Fear Mongers Didn't Want to Let Cassini Fly (2)

cusco (717999) | about 3 months ago | (#47400473)

And even then, multiple RTGs have been involved in launch failures and none have ever caused a problem. More often than not they were fished out of the ocean (US) or dug out of the tundra (USSR), refurbished, and used again on a later mission. I've never been clear on the mechanism the Luddites propose for the RTG to "vaporize" and then spread radioactive dust evenly throughout the atmosphere, targeting human lungs, either.

Re:Fear Mongers Didn't Want to Let Cassini Fly (0)

Anonymous Coward | about 3 months ago | (#47405113)

. I've never been clear on the mechanism the Luddites propose for the RTG to "vaporize" and then spread radioactive dust evenly throughout the atmosphere, targeting human lungs, either.

Well, it happened once... in the 60s, with life going on.. and NASA changed their designs before launching another one so it would not happen again.

Re:Fear Mongers Didn't Want to Let Cassini Fly (1)

Charliemopps (1157495) | about 3 months ago | (#47398985)

Keep in mind, that while he has had a lot of papers published, the majority of the physical models of the universe he's supported have now been proven wrong (or are pretty close to being proven wrong) He seems to support science that he thinks would be "Cool" if it were true, rather than based on evidence. His tendency to support sensational science applies to his academic work as well. He's even trying the Einstein crazy hair look. He's all show, and no go. I've never liked the guy.

Re:Fear Mongers Didn't Want to Let Cassini Fly (1)

arth1 (260657) | about 3 months ago | (#47399161)

Keep in mind, that while he has had a lot of papers published, the majority of the physical models of the universe he's supported have now been proven wrong (or are pretty close to being proven wrong)

Being proven wrong is a good thing in science. The more we prove wrong, the better supported our remaining hypotheses become. We need more people who come up with falsifiable theories that fit our current knowledge, so we can narrow things down further.

But yeah, the sensationalism is not doing science any favors. I cringe when I see Morgan "We only use ten percent of our brain" Freeman present Michio Kaku yet again.

Re:Fear Mongers Didn't Want to Let Cassini Fly (1)

cyberchondriac (456626) | about 3 months ago | (#47400593)

Being proven wrong is a good thing in science. The more we prove wrong, the better supported our remaining hypotheses become. We need more people who come up with falsifiable theories that fit our current knowledge, so we can narrow things down further.

But yeah, the sensationalism is not doing science any favors. I cringe when I see Morgan "We only use ten percent of our brain" Freeman present Michio Kaku yet again.

Are you referring to that movie with Scarlett Johansson? Yeah, I cringed bigtime when I heard that bullshit 10% premise trotted out once again; and worse, so many kids idolize Morgan Freeman (apparent via the memes and comments on sites like memedroid), that a good number of them are likely going to believe this hook line and sinker just because he's in the movie and seems to be confused with something of an authority due to his hosting Through the Wormhole.

Re:Fear Mongers Didn't Want to Let Cassini Fly (0)

Anonymous Coward | about 3 months ago | (#47397727)

It's not really that surprising if you have ever heard him speak or read any of his books. Michio Kaku is a crackpot. He hasn't actually accomplished anything, nor does he have the expertise to go up against real scientists because his form of "science" consists of nothing more than speculation and what ifs.

Re:Fear Mongers Didn't Want to Let Cassini Fly (2, Interesting)

Anonymous Coward | about 3 months ago | (#47395789)

That is an impressive estimate considering Cassini had about 33 kg of plutonium, while 200k deaths is the upper limit of estimates of deaths from Chernobyl (and considered way overestimating the deaths), which released nearly 6 tons of fuel and transuranics, plus a several thousand PBq of shorter lived isotopes and hundreds of PBq of medium lived isotopes (the 33 kg of plutonium is only 0.4 PBq and medium halflife of 87 years).

Re:Fear Mongers Didn't Want to Let Cassini Fly (1)

kwbauer (1677400) | about 3 months ago | (#47397337)

Surprising that "Mother Jones" would distort the truth, isn't it? What is even more surprising is that people have ever viewed them as a credible source of anything.

Re:Fear Mongers Didn't Want to Let Cassini Fly (1)

cyberchondriac (456626) | about 3 months ago | (#47400647)

Them and a hundred other media sources.

Re:Fear Mongers Didn't Want to Let Cassini Fly (0)

Anonymous Coward | about 3 months ago | (#47402981)

No, it doesn't take much Pu to poison a person, or a whole lot of people. And 33 Kg is a lot when viewed in that light...

From Wikipedia, and supported by other sources:

"...calculations show that one pound of plutonium could kill no more than 2 million people by inhalation." And you've got 33 X 2.25 lbs...

Re:Fear Mongers Didn't Want to Let Cassini Fly (0)

Anonymous Coward | about 3 months ago | (#47404993)

Chernobyl releasing [nature.com] nearly 60 kg of Pu241 and 250 kg of Pu239-240. Despite being right next to a Pripyat with a population of 50k and 120k people total in what is now the exclusion zone, and evacuations taking some time to even start, the number of deaths is quite small, even if compared to Kaku's 200k out of NYC or Tokyo's population. Short of issuing plutonium filled inhalers and forcing the population to use them, getting a large part of that plutonium to all go into people's bodies is non-trivial.

Re:Fear Mongers Didn't Want to Let Cassini Fly (1)

KeensMustard (655606) | about 3 months ago | (#47395631)

Now you mention it, no, I don't remember that. Maybe concerns were expressed and I didn't notice in the excitement and anticipation. Maybe those concerns weren't as widespread as you remember. In any case I don't think that should be the takeaway.

Re:Fear Mongers Didn't Want to Let Cassini Fly (0)

Anonymous Coward | about 3 months ago | (#47395741)

It was all over the popular media at the time. Protests, stories on CNN, the whole nine. To most normal people, that controversy was all the knew about the mission. Most people couldn't even have told you where it was going.

Re:Fear Mongers Didn't Want to Let Cassini Fly (1)

Gareth Iwan Fairclough (2831535) | about 3 months ago | (#47395791)

Now you mention it, no, I don't remember that. Maybe concerns were expressed and I didn't notice in the excitement and anticipation. Maybe those concerns weren't as widespread as you remember. In any case I don't think that should be the takeaway.

I do. It was incredibly big news at the time. I also recall similar protests about Galileo in the run up to that launch.

Re:Fear Mongers Didn't Want to Let Cassini Fly (1)

TapeCutter (624760) | about 3 months ago | (#47397593)

I remeber people making such claims but I also remeber everyone else laughing at them. I was more interested in the fact that the probe had to twice traverse a gap in Saturn's rings so as to put it in the right orbit when it arrived.

Re:Fear Mongers Didn't Want to Let Cassini Fly (-1)

Anonymous Coward | about 3 months ago | (#47396115)

I worked for a company that had something to do with building those power plants. For obvious reasons they kept it a big secret exactly how much radioactive material they had. I don't know the exact amount but it was a lot because they built several of them, and they were quite close to a major city. It would have set off some serious protests if the secret had gotten out.

Re:Fear Mongers Didn't Want to Let Cassini Fly (1)

motorhead (82353) | about 3 months ago | (#47399947)

Wankers

Re:Fear Mongers Didn't Want to Let Cassini Fly (0)

Anonymous Coward | about 3 months ago | (#47403063)

No, the hippies and others you deried raised a significant issue and that conversation caused the redesign of then-current and future RTGs so that they will survive both an exploding launch vehicle and reentry. That is a good thing.

We already blew up a bunch of these things, so the concern was not far fetched, either: Transit-5BN-3, Nimbus B-1, Lunokhod 1. The Apollo 13 RTG survived reentry and was used as the basis for the redesigned versions in operation today.

So, nyah nyah to you, too.

Re:Fear Mongers Didn't Want to Let Cassini Fly (0)

Anonymous Coward | about 3 months ago | (#47405067)

Depends on which hippies you mean, as the Cassini protesters certainly didn't influence the RTG design. Cassini used the same RTG design as used for Galileo and Ulysses, which were first built in 1986 and designed before hand, when the Cassini mission was just a recommendation to send something to Saturn, possibly with a lander. Your other dating seems kind of off a bit too, as it was the burn up of the Transit RTG that lead to the change in design, and by the time of the next use, all RTGs were designed to survive re-entry. How many hippie protesters were there for the Nimbus launch?

Big (4, Interesting)

Tablizer (95088) | about 3 months ago | (#47395251)

whose own work has been significantly informed by the tiny craft's output.

Tiny? I saw a clone in a space museum. That sucker is almost as big as a bus.

Anyhow, as a science mission, it has to rank up there almost with the Voyagers in terms of new and fascinating discoveries.

did they (0)

ozduo (2043408) | about 3 months ago | (#47395329)

discover Unobtanium?

Flagship Missions (4, Informative)

mbone (558574) | about 3 months ago | (#47395335)

Viking, Voyager, Galileo, Cassini - these were the so called "Flagship" missions - big, envelope-pushing missions intended to substantially advance our knowledge of the solar system. (MSL is really another, but Mars is special for NASA and so they don't call it that.) They have somewhat fallen out of favor, as they are very expensive and prone to delays and overruns, but it is hard to see how there can be substantial advances, particularly in the outer solar system, without them.

The next mission of this class will, Congress willing, be the Europa-clipper, which is slowly getting to the AO stage [nasaprs.com] . I can hardly wait.

Re:Flagship Missions (1)

neilo_1701D (2765337) | about 3 months ago | (#47395439)

Don't forget Pioneer 10 and 11...

Re:Flagship Missions (1)

hackertourist (2202674) | about 3 months ago | (#47398053)

Pioneer 10 and 11 predate the "Flagship" moniker. They also weren't really flagships: they had a limited science package and were designed for low cost, their mission was to see what circumstances the Voyagers would encounter and determine the feasibility of the Voyager mission.

I don't mean to disparage the achievements of Pioneer 10 and 11, by the way. It's just that NASA attaches a specific meaning to "Flagship" and the Pioneers didn't fit that bill.

Re:Flagship Missions (2)

Tablizer (95088) | about 3 months ago | (#47396437)

Galileo unfortunately had a main antenna failure, limiting it's imaging capabilities as a weak backup antenna had to be used instead. It still did great science, though, even though imaging had to be carefully cherry-picked.

"Scientists says" (-1)

Anonymous Coward | about 3 months ago | (#47395483)

News for nerds. Stuff that matters.

Titian Hero (3, Informative)

Tablizer (95088) | about 3 months ago | (#47396509)

The man who saved the Huygens lander:

"...Smeds was able to confirm the existence of the flaw only after pushing through an extensive series of tests that was initially rejected by mission managers as unnecessary.

Smeds confirmed the existence of the fatal software flaw in the Probe Support Avionics (PSA), mounted onboard Cassini, in a series of tests conducted in February 2000...

"They said it was too complex," says Smeds, adding, "But then I started to investigate the equipment available at JPL's ground stations..."

http://www.esa.int/Our_Activit... [esa.int]

Spacecraft (1)

tquasar (1405457) | about 3 months ago | (#47397041)

Pioneer 10 and 11 launched in 1972 and 73, not functioning yet still going into deep space. Voyager I and 2 still going in interstellar space over fourteen light years away from Earth. http://www.nasa.gov/centers/am... [nasa.gov] http://voyager.jpl.nasa.gov/in... [nasa.gov]

Re:Spacecraft (0)

Anonymous Coward | about 3 months ago | (#47397745)

Voyager I and 2 still going in interstellar space over fourteen light years away from Earth.

Erm... no.
Voyager 1 is currently (approx.) 35 light HOURS from earth.
Voyager 2 is currently (approx.) 29 light HOURS from earth.

Source: http://voyager.jpl.nasa.gov/where/

Re:Spacecraft (0)

Anonymous Coward | about 3 months ago | (#47399629)

Actually, 35 hours is *roundtrip* light time, so Voyager I is less than 18 light-hours from Earth.

Re:Spacecraft (1)

rhodium_mir (2876919) | about 3 months ago | (#47401737)

Voyager I and 2 still going in interstellar space over fourteen light years away from Earth.

Voyager I is 127.6 AU away from Earth which is closer to 0.002 light years.

Another Paid Advertisement? (0)

fygment (444210) | about 3 months ago | (#47398513)

So at least two stories [see also Project Neptune [slashdot.org] ] today from anonymous readers, reminding us of long standing projects that have been mentioned here before. Interestingly both have some Canadian content.

Both really kind of non-stories, just PR or paid advertisements.

Re:Another Paid Advertisement? (1)

barakn (641218) | about 3 months ago | (#47400301)

Apparently you are unaware of the news industry's habit of fluffing up its content volume with pieces commemorating the anniversaries of semi-significant events, especially anniversaries that occur in multiples of 5 - something to do with the number of digits on our ape paws.

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