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Spacecraft to Fly Through Geyser Plumes On Saturn Moon 80

Posted by Zonk
from the fueling-station-coming-soon dept.
Riding with Robots writes "Today the robotic Saturn probe Cassini will make its closest buzz ever over the surface of the enigmatic ice moon Enceladus, whose surprising giant water geysers hint at a hidden ocean of liquid water. The spacecraft will fly right through the tops of the geyser plumes in order to sample the material that originated beneath the surface. NASA is offering a video, interactive guide and image gallery in advance of the event."
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Spacecraft to Fly Through Geyser Plumes On Saturn Moon

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  • It can really analyse the water samples? Wow, I'm impressed.

    NASA really wants the probe to get a wash down.
    • by rijrunner (263757) on Wednesday March 12, 2008 @03:43PM (#22731806)

          The probe was going to be flying around the rings of Saturn, so they added the Cosmic Dust Analyzer, which can analyze dust particles. For the type of thing they are doing here, they can treat water as a dust particle as it will freeze. It is particulate matter.

       
      • by iamlucky13 (795185) on Wednesday March 12, 2008 @07:12PM (#22733922)
        It should be noted, it also has a mass spectrometer. While this can't identify whether a given particle is dust or ice, I believe it can determine the ratio, so while measuring density on the cosmic dust analyzer, they can make a good guess how much of it is water and how much is dust based on the results from the spectrometer.

        And furthermore, Cassini will fly a mere 32 miles over the surface of Enceladeus. Considering the detail visible from 2600+ miles away [nasa.gov] on a pass several years ago, there should be a couple really great images result from this pass.

        It's rather amazing to think that NASA can successfully fly this spacecraft within 32 miles of an object 300 miles in diameter, while moving at 32,000 mph in an elliptical orbit that carries it over 1 million miles away from Saturn at the extreme, with very limited manuevering fuel. Go Cassini!
        • by ashitaka (27544)
          In this case unfortunately so close is too close and the speed is what kills it. Take a photograph of a racing car moving at 200 mph on the opposite side of a race track is no problem. Taking a picture of that same racing car as it passes 2 feet in front of you is pretty much impossible.

          Cassini's cameras can't focus on the surface moving by so quickly. Should result in some spectacular approach and departure sequences though.
    • Re: (Score:3, Informative)

      by K. S. Kyosuke (729550)

      It can really analyse the water samples? Wow, I'm impressed.

      This...is...Star Trek! ;-)

      Actually, you can do quite a lot with computer-controlled devices that the original manufacturer did not intend originally. Galileo, for one thing, was capable of transmitting a huge amount of data even though it was crippled so much that anyone except the JPL people would probably give up [wikipedia.org]. I bow to those guys. Perhaps they are going to use this [nasa.gov]?

  • by sighted (851500) * on Wednesday March 12, 2008 @03:27PM (#22731626) Homepage
    I should add that although the closest approach to Enceladus is happening as I type this, Cassini won't have a chance to turn its antenna toward Earth until later this evening (U.S. time). The downlink will take several hours, so the first pictures probably won't be publicly available until tomorrow.
    • Re: (Score:1, Funny)

      by Hatta (162192)
      Mmmm enchiladas. Wait what?
    • by CheshireCatCO (185193) on Wednesday March 12, 2008 @04:02PM (#22732022) Homepage
      Early afternoon is, I believe, the plan. JPL (http://jpl.nasa.gov) and CICLOPS (http://ciclops.org) are both planning releases that I know of.
      • by ozbird (127571)
        First image [livingindryden.org] just in - film at 11.
        • Look at the detail of that surface! The crystalline structure that absolutely must be frozen water! There are areas that could be mountains surrounded by flat plains that echo the visions of the frozen worlds of the earliest space artists!

          • by ashitaka (27544)
            The management would like to apologize for the previous post which was intended as a sarcasm test.

            Anyone who replies calling me an idiot for not recognizing a frost-covered window pane should be sacked.

            Yes, it's cold in Dryden.
    • >the first pictures probably won't be publicly available until tomorrow.

      At closest approach (50 km.) Cassini will be going far too fast to take any photographs.

      • Re: (Score:3, Informative)

        by sighted (851500) *
        Definitely, but there should be some interesting shots from other portions of the flyby, especially of the north polar region, not to mention the other kinds of data that is expected to come down.
    • Re: (Score:2, Informative)

      by Peter Lake (260100)
      Cassini started sending the data back to Earth few hours ago (around 7:00 pm PDT). Hopefully we'll get to see the first images by thursday morning about 5:00 AM PTD.

      Here's an animation of the flyby, you can see the spacecraft's close trajectory and how various instruments in their turn take measurements of Enceladus: http://www.youtube.com/watch?v=9Pfz1n6tMUg [youtube.com]

    • by sighted (851500) *
      NASA's raw Cassini image feed [nasa.gov] is getting hammered pretty hard at the moment, but there are a few shots here [ridingwithrobots.org] too.
  • At closest approach to Enceladus, Cassini will be only 50 kilometers (30 miles) from the moon.
    Seriously, cheers JPL. That's pretty hardcore.
  • by garett_spencley (193892) on Wednesday March 12, 2008 @03:37PM (#22731732) Journal
    I already sampled the water from the geysers on Enceladus back in '78 at a Greatful Dead concert.

    Tasted kind of sweet with a hint of mint.

    NASA needs to get with the times. They've got 30 years of catching up to do.
    • by syousef (465911)
      Does the name remind anyone else of Enchaladas or is it just me?

      Water of Enchaladas....mmmmmm....lets bottle it!
  • by LiquidCoooled (634315) on Wednesday March 12, 2008 @03:38PM (#22731750) Homepage Journal
    If they don't have wipers on their nice expensive spaceship isn't there a chance they could ruin the camera images with droplets and splattered bugs etc?
    • Re: (Score:1, Funny)

      by Anonymous Coward
      Ah yes, but wipers alone would not be sufficient to get the sticky bug guts off the lens. They'd need some pretty heavy duty washer fluid too.
    • Re: (Score:3, Insightful)

      by ShatteredArm (1123533)
      I'd think they'd be happy to make such a groundbreaking discovery as bugs on Saturn's moon.
    • by StefanJ (88986) on Wednesday March 12, 2008 @03:49PM (#22731878) Homepage Journal
      Well, the initial plans called for wipers, but that would have required another .4 kg of expensive plutonium pellets in the RTG, and the added mass of the motor, intermittent-wipe controller, and the mechanism for changing spare wiper blades would have meant that the hermetically sealed capsule containing the Blob (frozen by Steve McQueen in the 1950s) would have been bumped to another deep-space probe.
    • The optical instruments won't be set to the ram direction during a plume pass.
  • We need a nice, interactive "Google Saturn" to help us along the way.
    • Re: (Score:3, Interesting)

      by Corf (145778)
      This is pretty close [wikimedia.org]. On a related note, HOLY SHIT. I used to think orbital dynamics and the physics of space navigation were way over my head. Now, I realize they're way way way over my head. Does this thing even have thrusters of any kind, or did they shoot it into the sky, give it a push, and all this was planned out?

      Hats off to the JPL nerds who made this work. I am floored.

      • by icebrain (944107) on Wednesday March 12, 2008 @04:30PM (#22732324)
        Yes, it has thrusters. Midcourse corrections happen every now and then.

        It's not so much that orbital mechanics is hard; a lot of it is just brute-force computation. The hard part is getting reliable data to base said computation on.
        • by isomeme (177414) <cdberry@gmail.com> on Wednesday March 12, 2008 @06:22PM (#22733434) Homepage Journal
          Getting good data is hard, but good course planning is also hard. It's easy to find an orbit that will work; push an object sideways around a mass at any of a wide range of velocities, and voila, it's in an orbit.

          What's hard -- and really as much an art as a science -- is taking the laws of orbital mechanics, the very restricted maneuvering-fuel budget, and several thousand science goals (often mutually excusive), and turning them into an efficient mission plan.

          Then add to that dealing with the unexpected. The Cassini team had a whole orbital tour worked out before launch, then discovered while the probe was already en route to Saturn that they needed to completely change the orbital geometry for the Huygens probe's Titan descent to compensate for a radio design snafu. They succeeded in not only rejiggering nearly all the planned science to fit into a new orbital tour, but also in grabbing a few resulting new opportunities for observations along the changed route.

          The best analogy I can think of is to the difference between generating a set of legal chess moves, and a set of good chess moves.
          • Very true, although it's a bit more complicated still: chaos pretty well guarantees that even if you plan out a great trajectory in advance, you'll drift and end up in trouble down-stream. Plus there are inevitable changes required due to problems (like with Huygens or changing models of the Titan atmosphere) or due to changing objectives: someone wants to go closer to a given moon, that takes arranging.

            A lot of trajectory planning seems to be an art, from where I stand on the sidelines (albeit with a dece
            • Re: (Score:2, Informative)

              by Tablizer (95088)
              Very true, although it's a bit more complicated still: chaos pretty well guarantees that even if you plan out a great trajectory in advance, you'll drift and end up in trouble down-stream. Plus there are inevitable changes required due to problems (like with Huygens or changing models of the Titan atmosphere) ...

              It's not so much "trouble", but rather using up more course adjustment fuel to compensate for errors in reality versus the model. After every moon pass-by they can use the cameras to check the pro
              • The less fuel you have, the shorter the mission and/or less chances to change your mind.

                Yep, reaction mass (Cassini doesn't have fuel per se) is one of the most common limiting factors in missions. (Although it should be noted, not the only one.) As the mission wears on, we're having to scale back the kinds of things we want to do with the spacecraft because the reaction mass is getting too precious.

                One minor quibble, you don't just do navigation images after a fly-by. They're being taken all the time to monitor the spacecraft's trajectory.

          • Re: (Score:2, Interesting)

            by Tablizer (95088)
            needed to completely change the orbital geometry for the Huygens probe's Titan descent to compensate for a radio design snafu.

            That's an amazing story in itself. The dude who discovered the problem did it on a hunch, barely got funding to check into the issue, and was almost ignored when he uncovered the problem. It would make a great "nerd drama" movie.
                 
      • by sighted (851500) *
        This is even better: an interactive, 3D version [nasa.gov]
  • by Satanboy (253169) on Wednesday March 12, 2008 @03:52PM (#22731918)
    Maybe it will find something like the andromeda strain [wikipedia.org].

    Now, that would be something.

  • by ezwip (974076)
    I remember the good old days when they'd tell you to rewrite your book report for talking about water in space.
  • Oblig... (Score:3, Funny)

    by BenSchuarmer (922752) on Wednesday March 12, 2008 @03:54PM (#22731938)
    That's no moon!
  • by delibes (303485) on Wednesday March 12, 2008 @04:02PM (#22732012)
    In 2061 [wikipedia.org] (written over 20 years ago now) captain Smith fuels his spacecraft with water from Halley's comet and then flies through a geyser to clean the ship. The 'cosmic car wash manoeuvre' always struck me as crazily risky, but now it looks like someone at NASA thinks it's good clean fun :) Hopefully Cassini won't get too much of a blast at a distance of 50km.

    Also, since there's hydrocarbons on Titan and ice in the rings and moons of Saturn, I think Clarke picked the wrong gas giant to send his characters to! Saturn's got it going on.

    • by Drooling Iguana (61479) on Wednesday March 12, 2008 @04:22PM (#22732248)
      Clarke did pick Saturn. Kubrick changed it to Jupiter to make the special effects easier. The sequels to 2001 were written as sequels to the movie, not to the book.
      • Which is why Silent Running used Saturn as a backdrop - Douglas Trumbull (Who did the SFX for both) recycled test footage from 2001 as stock footage for Silent Running.
    • Re: (Score:3, Informative)

      by rbanffy (584143)
      For 2001, Clarke picked up Saturn. The monolith was in Iapetus.

      Only the movie (and subsequent books) mentions Jupiter. It makes sense, as more people watched the movie than read the book. In the book, they use Jupiter to accelerate Discovery towards Saturn, but Kubrick (IIRC) thought this would confuse the audience (like the Bowman meeting with the monolith in the hotel room after the psychedelic trip would be readily understood) and Saturn was dropped. Douglas Trumbull used the techniques developed during
    • by odyaws (943577)

      In 2061 (written over 20 years ago now) captain Smith fuels his spacecraft with water from Halley's comet and then flies through a geyser to clean the ship. The 'cosmic car wash manoeuvre' always struck me as crazily risky, but now it looks like someone at NASA thinks it's good clean fun :)

      Probably not a coincidence that Clarke also wrote some books with Gentry Lee [wikipedia.org], one of the chef engineers at JPL, so he certainly had good sources for this stuff (though 2061 was written a few years before Clarke first p

    • by Ihlosi (895663)
      Also, since there's hydrocarbons on Titan and ice in the rings and moons of Saturn, I think Clarke picked the wrong gas giant to send his characters to! Saturn's got it going on.



      I don't think that the 90 km-deep ocean on Europa is anything to sneeze at. Unfortunately, it's under a few km of ice.

  • by CheshireCatCO (185193) on Wednesday March 12, 2008 @04:05PM (#22732044) Homepage
    The spacecraft is flying 200 km from the south pole of Enceladus. The plume extends *thousands* of kilometers into space. We're not passing through the top of the plume by any means. We're getting right into it.
    • Re: (Score:3, Insightful)

      by tcolberg (998885)
      I don't think NASA would put Cassini into any significant danger, considering that the probe is still doing a lot of good work. But think of the science being done here! This is why we should be putting more money into our robotic missions. We don't even need to qualify them by saying they can do some things more efficiently than humans, they can do things right NOW that we meatbags have no chance of doing for at LEAST another century!
      • Any time any maneuver like this is considered, there's a study group assembled to examine the risks. As some articles are mentioning, a 25-km flyby was considered, but was deemed a little too risky after looking at the studies.
      • by Otter (3800)
        I don't think NASA would put Cassini into any significant danger, considering that the probe is still doing a lot of good work.

        The video on the JPL site explains that at the altitude at which they're passing through the plume, the only particles are micron-sized and don't threaten the craft at all. Larger particles can't get up that high.

    • If this image [nasa.gov] is any indication, then it pretty much is the top of the plume.
      • It's not. The plumes extend well beyond 1000 km. And you'll notice that we cut through a much brighter (hence denser) part of the plume before passing under the moon as well.
    • >The plume extends *thousands* of kilometers into space

      Megameters! And other distances relatively unfathomable ...
      • You know, I've been valiantly trying to get "megameters" accepted in my discipline, but I'm having little luck. I sort of snapped when I saw someone label a plot in "kilo-kilometers".
    • by Hillgiant (916436)
      This is the captain. We have a little problem with our entry sequence, so we may experience some slight turbulence and then - explode.
  • get Ring Around the Cawh-lur?
  • And thats no geyser either...
  • You'll piss it off.
  • All These Planets Are Yours Except Europa, Attempt No Landing There ...

    I know it's not Jupiter
  • by ecavalli (1216014)

    NASA is offering a video, interactive guide and image gallery in advance of the event.

    Well that's cool, but more importantly, will NASA be offering the same sort of media of the actual event?

    I have to imagine those pictures would be much more interesting.
  • ...welcome our soggy robotic pinball-moon-wizard overlord.
  • the enigmatic ice moon Enceladus, whose surprising giant water geysers hint at a hidden ocean of liquid water.

    Damn, I keep mixing them up. I thought Enceladus was the one that was "very noted for its exciting sit coms but ravaged by vicious mountain goats".
  • NASA's raw Cassini image feed [nasa.gov] is getting hammered pretty hard at the moment, but there are a few shots here [ridingwithrobots.org] too.

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