Follow Slashdot stories on Twitter

 



Forgot your password?
typodupeerror
×
Space EU NASA

Cassini's Space Odyssey To Saturn 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.
This discussion has been archived. No new comments can be posted.

Cassini's Space Odyssey To Saturn

Comments Filter:
  • by Anonymous Coward on Sunday July 06, 2014 @04:27PM (#47395193)

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

    • by Trepidity ( 597 )

      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.

      • by mbone ( 558574 )

        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.

      • by rogoshen1 ( 2922505 ) on Sunday July 06, 2014 @04:54PM (#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.

        • by Trepidity ( 597 )

          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.

          • by Gareth Iwan Fairclough ( 2831535 ) on Sunday July 06, 2014 @06:29PM (#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.

            • by arth1 ( 260657 ) on Sunday July 06, 2014 @07:23PM (#47396071) Homepage Journal

              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.

              • 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.

                • by nadaou ( 535365 )

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

                  • 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.

                    • by prgrmr ( 568806 )
                      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
                    • by cusco ( 717999 )

                      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.

              • 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.

                • by arth1 ( 260657 )

                  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.

                  • 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: (Score:2, Interesting)

          by Anonymous Coward
          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).
          • 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.

    • 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.
      • 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.

      • 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.
  • Big (Score:4, Interesting)

    by Tablizer ( 95088 ) on Sunday July 06, 2014 @04:36PM (#47395251) Journal

    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.

  • Flagship Missions (Score:5, Informative)

    by mbone ( 558574 ) on Sunday July 06, 2014 @04:52PM (#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.

    • Don't forget Pioneer 10 and 11...

      • 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.

    • by Tablizer ( 95088 )

      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.

  • Titian Hero (Score:4, Informative)

    by Tablizer ( 95088 ) on Sunday July 06, 2014 @08:43PM (#47396509) Journal

    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]

  • 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]
    • 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.

  • 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.

    • by barakn ( 641218 )

      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.

Single tasking: Just Say No.

Working...