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Space Science

Sea Gliders for Other Worlds 147

Posted by michael from the europa-cruiser dept.
An anonymous submitter writes: "NASA has, for the moment, killed funding for research leading to an underwater probe for Europa's suspected saltwater ocean. But it's possible that this is a good thing. SPACE.com proposes that U.S. Navy-funded research into underwater gliders could offer a superior means of probing Europa, exploring Venus, and even diving into the methane/ethane seas of Titan. NASA wanted a big battery and propeller machine under the ice of Europa, but that might break down, stir up water that should left undisturbed, and leak lubricants into a pristine research environment. The navy wants gliders with internal actuators because they have no flaps or propellers, no lubricant, and one already exists that could "fly" under the Pacific from Seattle to Tokyo on a penlight battery! Another model uses no batteries for locomotion at all, but instead taps heat gradients."
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Sea Gliders for Other Worlds More

Sea Gliders for Other Worlds

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  • For the geek that has everything. (Score:3, Funny)

    by PopeAlien ( 164869 ) on Wednesday April 10, 2002 @03:25PM (#3319097) Homepage Journal
    Well once you've got your own luxury submarine [slashdot.org] this would be a good toy to take along with you beneath the waves.

    • Geek Factor THIS! (Score:2, Interesting)

      by cosmol ( 143886 )
      There was talk on the geocaching list years back about a marine geocache. Of course there would be gps on board and a small thruster to move it around the ocean. It would obviously have to be powered by solar cells.

      This gliding technology seems like a perfect fit. Low power consumption, intermittent surfacing, and a simple principle.

      While I'm daydreaming, wouldn't it be cool to send one of these things (or any homebuilt autonomous vehicle) around the world?

      Forget the X prize, I'm offering the C prize (amount TBA) to the first person who does this with less than $500.

      You'd need an efficient drive system, sail or this gliding technique comes to mind. Of course a gps, and modest CPU, a linux ucSimm perhaps. Put it all together in a solid seafaring shell, slap some solar panels on it and let it go.

      You'd want to keep track of it, but I'm not sure what satellite/radio options exist. HAM would only work near civilization, and satellite is probably too expensive. But that is only a minor obstacle :)

  • Contamination avoidance (Score:4, Insightful)

    by PD ( 9577 ) <slashdotlinux@pdrap.org> on Wednesday April 10, 2002 @03:27PM (#3319117) Homepage Journal
    Even if the device is hermetically sealed, it seems that contamination can't be avoided. For example, the little pump would have lubricants in it. No matter how the thing is sealed, eventually water will get in and the lubricants will get out. Even a solid glass sphere won't last forever. What the difference between contaminating Europe today, or doing it a million years from now? The point is to avoid contamination, right?
    • What the difference between contaminating Europe today, or doing it a million years from now?

      Actually, Europe has been contaminated for a long, long time already. ;-)

    • Re:Contamination avoidance (Score:4, Insightful)

      by jweb ( 520801 ) <jweb68.hotmail@com> on Wednesday April 10, 2002 @03:37PM (#3319180)
      The point is to avoid contamination, right?

      Europa exploration basically boils down to two choices: Explore and risk contamination, or don't explore and miss the learning and discovery opportunities present.

      Assuming we go with the first option, our stance should be to do as much as possible to avoid contamination. While we will never be able to avoid contamination (even if this thing never breaks, corrodes, or wears out, it'll still be a contamination in the sense that it was artificially placed there), this idea seems to be the best one yet to minimize the impact of any exploration device we create.
      • Assuming we go with the first option, our stance should be to do as much as possible to avoid contamination.

        Well said. I just wonder why we aren't this careful when exploring/acquiring resources here on Earth? Socio-economic forces seem to step right in and destroy otherwise pristine areas for the sake of profit. Drilling for oil in the Alaskan wilderness anyone?

        What makes us think that, if the exploration phase finds something of 'value', that the exploitation phase won't begin? If this happens, concerns about the 'contamination' of Europa will be lost amid the scramble for possible windfalls.

        • While I am generally in favour of taking care not to unnecessarily harm the surrounding environment of any place we visit, I am glad that this enlightened attitude has not always been a goal of mankind. I would hate to live in a cave and be fearful of getting eaten by cheetahs. That would seriously distract me from reading slashdot.
          • Way to over-simplify the point. There's progress. And then there's destructive progress. It seems to me that many times we choose the destructive path. Seemingly out of disregard for our own environment and ultimate safety. My question is; why are we more concerned with the environment of Europa (or other bodies millions of miles away), than we are with our own 'back yard'?
            Don't get me wrong. I'm glad that the people talking about this exploration are concerned about keeping the test environment as pristine as possible. I just don't get why we can't approach things here on Earth the same way.

            • You are right, it is an oversimplification. I wasn't trying to be insightful, just funny. I think that we worry more about far away places for a couple of reasons:
              One: Its easier to worry about Europa than Cleveland because its far away and we don't have to get practical work done there.
              Two: We worry more about places that are more pristine to begin with. Its impractical to worry about the minute contamination of a place when we've already wiped out 10% of its native life.

              But we do worry some about our planet; especially the places that are still pristine. It is an oversimplification to assume we don't.
    • forget all that, how about whatever the probe itself is made out of. Is fibreglass/aluminum/carbon fibre a naturally occuring substance in the target environment. And we haven't even begun to talk about micro contaminants on the surface of the vessel (dust, spores, oils from the fingers of the last guy to work on it, etc). Let's face it, ANY type of active investigation (vs passive) WILL contaminate to a degree that which you are investigating (observe my careful avoidance of the word "probe" in the last sentence ;)
      • Not a bad idea...make it out of a native element.

        Lets send a probe up there to get a sample so we know what is native and in what amounts :)

        Couldn't resist. Then again, for all we know, our passive means (radio/infrared/xray) may also be having an effect.
        • If they're passive then they can't have an effect (they would be active). You don't fire a beam to examine spectra, stuff emits/reflects/transmits electromagnetic energy already. Letting that enery hit you doesn't have any effect unless there is quantum entanglement - but that effect is entirely natural anyway.
    • What the difference between contaminating Europe today, or doing it a million years from now? The point is to avoid contamination, right?

      Well, by a million years, hopefully we will have gone back in person to clean up our mess.

    • The sentient life forms that evolved on europa will wonder if their world was seeded with life by an alien species.
    • What the difference between contaminating Europe today, or doing it a million years from now

      Europe in a million years will be far from the polluted closet it is today, so polluting now would have less of an impact.

    • First, this is not a cleanroom or even your grandmothers living room. It's an unprotected wilderness moon where all sorts of space junk has fallen on it since the beginning of time. As long as we're not worse than that, there is nothing to worry about.

      Second, if we do something today that contanimates Europe in a million years, that means we have one million years to conduct more research.

      In reality, we'll probably need at most a few decades until we've found out all we need to know about it, and can turn it in to something more useful. Or if it turns out to house something very delicate that we'll want to preserve for eternity, we have a million years to stop the future pollution from happening.

  • Sounds cool ... (Score:4, Funny)

    by thud2000 ( 249529 ) on Wednesday April 10, 2002 @03:28PM (#3319128)
    But will it probe Uranus?

  • Now we can populate the sea!
  • Why dont they just use that nifty sub that the Gungans Gave Qui Gon and Obi Wan, It seemed to be echo firendly, and we can finally send Jar Jar away and he will never come back!

  • Eco-Friendly on Europa? (Score:2, Insightful)

    by Anonymous Coward
    Isn't it odd that they are concerned about damaging the environment on Europa, when producing the ability NOT to will do harm to our environment?

    Go Fish.

  • Probing Europa? (Score:5, Funny)

    by Blackheart2 ( 161473 ) on Wednesday April 10, 2002 @03:39PM (#3319186) Homepage
    Don't they know better?
    all these worlds are yours
    except europa
    attempt no landing there
    use them together
    use them in peace
    • Well, thank God I am not the only one to think such....I am a certified astro-geek...but I do not stand alone.
    • Oh C'mon...all we have to do is wait 1000 years until Jupiter turns back into a white dwarf, then we can land there all we want.

      B

    • Use Them Together (Score:2, Informative)

      by Mad Man ( 166674 )
      Actually, the book "2010" (1982) didn't contain the part about "Use them together, use them in peace."

      That was added in the movie (1984), along with the armed conflict between the USA and the Soviet Union in Central America.

      For some reason, Peter Hyam cut out the part about the Chinese ship "Tsien" that did land on Europa, and added the political aspect.

      He must have been smoking some good crack if he thought that was an improvement on the book.

      • 2081? (Score:1)

        by deepone ( 554 )
        Wasn't that with the chinese ship in 2081?
        Was a long time since I read these books so I might very well be confused... :)
  • Whatever happenned to the electromagnetic drives the navy was working on? seems to me that using magnetic fields to slither through water is preferrable to beating your way around with fins, propellers, etc.

    • Re:Caterpiller drive (Score:3, Informative)

      by tenman ( 247215 )
      Electromagnetic drives to move a vessle in water proved to be to high a challenge to fund. While we are still working on effecencies, the current weight to thrust ratio is that of a model rocket engine pushing an adult's mountain bike. The technology is improving, but with funding this low, we spend a lot more time at our desks then we do in the labs.

  • Problems with a reverse heat gradient (Score:5, Insightful)

    by lkaos ( 187507 ) <anthony@nOSPAm.codemonkey.ws> on Wednesday April 10, 2002 @03:42PM (#3319212) Homepage Journal
    First of this is incredible technology. Low-impact approachs to exploration are absolutely what we need to avoid screwing up other planets as we have with this planet. Its always bothered me that we trash on Mars... but anyway, one comment in the article struck me as odd:

    On Venus or Europa, that process is somewhat reversed. [...]

    "A reversed gradient is nothing I would be too concerned about [...]"

    So, if there is a reverse gradient, then doesn't that also mean that there is going to be extrordinary convection currents as the heated (and less dense) material rises to the surface. While there logically would also have to be a down current, the mediums would have to be really turbulent.

    So, in order to heat up the machine to obtain energy to move actuators, one would have to deal with the turblence (in order to get to the heat source). I wonder if batteries are need in some way...

    Now the real question is, how do we get these things off of the planet (or safely disposed of) once they are done being used.

    I think this is a question that needs to be addressed more often (low-impact exploration). Who knows what kind of effect our stuff could have on other forms of life. If there were batteries, they would eventually have to leak and then there's battery acid polluting an environment.

    The reason this low-impact is important is because it means we can do _more_ exploration without having to worry about the effects.
    • Not only are you correct about the heat flow changing the way we think about water (we could feasibly due tests near to "lava" rifts in our own ocean floor to make sure it works)...there is a lot of speculation as to its center. If it gets there, and the heat gradient has been misjudged...then the balance will be off. If it gets there, and it turns out that the heat gradient is extremely variable from one point to another...then the balance will be off.

      Also, if it gets there...and it turns out the liquid is too thick or (due to extra-fluid movement) too thin...then...yep, the balance will be off. The fact is that, while I am almost in love with the tech-idea, I don't want to wait for six or seven years just to say "Oops...let's try again, adjust up point 03 on the reaction slope" and then wait another how many years to here "Oops...ok, we are going to need..."

      Dang it! It would break my Heart!
      • Yeah, I don't see how they could not have some kind of computer system on board in order to be able to compensate. Really, they need AI to control it anyway (the lag between Europa and even Venus would be to high to do anything real time).

        Not to mention the difficulty in transmitted data from underwater...

        Well, I'd like to see some work done here on Earth with these things, but man, it's an awesome technology...
      • not only is he right, but your right. All data point to the fact that any thickness or heat miscalculation regarding the fluid will result in the balance being off. But I have to differ about one this. It would seem that if a monkey can do sign language, then your love with the tech-idea will fade. I know this because one day the monkey will give you the ASL sign for up yours, and you will not be very happy about it. We all know that one man can not serve to masters, so it is impossable to say that you could be in love with the tech-idea and at the same time in love with the monkey who is punking you from behing.

        So in conclution. your "Oops lets try it again" timeline is wrong and I think you know it. But I still agree about the weight thing.
    • For atmospheric stuff, I would hope they glue a couple of solar cells on the thing. Do we have solar cells that would resist the heat and acidity of the Venusian atmospere?

      Also, what you say about turbulence is right, but makes me think that it would work to our advantage if there is a smart computer inside calculating and then moving into columns of updraft. This is the basic theory behind gliders.

      Also, in turbulent currents that just throw a craft around, why not build in a motion reciprocation system like in those Rolex watches that don't need batteries because they run off the mechanical energy of your arm movements? I think these are all good ideas to explore, and I agree with the poster that all this makes more sense than the battery+propeller diver that was proposed.

      • Do we have solar cells that would resist the heat and acidity of the Venusian atmospere?

        I think a more appropriate question would be do we have any solar cells that work in the near-total darkness that exists anywhere close to the surface of Venus. I think not. b-)

        The idea of using the energy flows that exist within the local environment is a good one, though. Your Rolex idea is a great one. On Mars, we should use solar cells (or perhaps heat reservoirs that take advantage of the large temperature differences between day and night). In the atmosphere of Venus, I don't know, maybe we could use some chemical process similar to that used by the bacteria found in ocean vents. OTOH that would seem to imply some openings to the environment, and that's sort of what we're trying to avoid here.

        The larger point is that it's ridiculous to power probes using radioactive crap like we've done in the past.

        later,
        Jess

    • So are you saying that we should not blow it up to see what's inside?

      What about just shooting depleted uranium spikes into it?

      If we look at it, will it still be the same?

      Are you saying, if we explore Uranus, then we should use a condom?

    • So, if there is a reverse gradient, then doesn't that also mean that there is going to be extrordinary convection currents as the heated (and less dense) material rises to the surface. While there logically would also have to be a down current, the mediums would have to be really turbulent. Actually, it's a little more complicated than that. The density of a fluid parcel (such as in the atmosphere) depends on several factors, including temperature, pressure, and composition (for example, water vapor content in Earth's atmosphere, or salinity in the ocean). The distribution of all of these properties affect the stability of an atmosphere. So, it is possible to have a stable atmosphere that is heated at the bottom, as long as the lapse rate (the change of temperature with height) isn't too large.

      The question `how large is too large?' depends on the details of the atmosphere in question. This website [nmsu.edu] has some numbers for various atmospheres in our solar system. With a measured lapse rate of about 7.7 K/km, there probably isn't a lot of spontaneous convection due to purely thermal forcing going on on Venus.

      Of course, turbulence can be forced in a wide variety of ways, so the absence of strong convection doesn't mean there isn't turbulence on Venus.

  • This reminds me of a story posted recently about the story on Lifters [jnaudin.free.fr] posted here a while back. Also on that page was a section about A Serrano's Field Propulsion Thruster [jnaudin.free.fr]. This little device can actually propel itself in a vacuum without any moving parts, according to the site. If one of these were combined with the Glider, perhaps that would be even better. Just a thought.

  • For the North Americans (like me): Penlight Batteries are just AA batteries.
  • "Inside Webb's craft is a cavity filled with an organic liquid compound that contracts when cooled and expands when warmed"

    It seems to me that sending an organic liquid to another planet could possibly be a bad idea. Wouldn't that be a bad contamination?
  • I don't think we will have the materials that could survive for any meaningful period of time on venus for quite sometime, especially with the current NASA emphasis on keepking price down. http://www.asnsw.com/articles/btbv-lm.htm In March 1982, the Soviet Union's Venera 13 and 14 spacecraft transmitted the only color photos ever taken of the Venusian surface. The probe did not last very long, and as I recall it was not for lack of $$ and design put into it. Did it not have a diamond lens on its camera??
  • First thing I though of when I saw the ship.

    Probably a little more eco-friendly that the SeaQuest was, but gotta love the design
  • Isn't that frustratingly slow? Or are they counting on Ocean currents to boost the speed?

    • Re:Only 1 Knot? (Score:2, Interesting)

      by wyrmis ( 570060 )
      Actually, I think they are shooting for frustatingly slow. Perpetual motion is not an option...and longly-sustained-low-energetic motion is only an option for a fair time. Longly-sustained-high-energy is almost unattainable as far as we know. So, they have to go with low-energy to make it longer-sustained. At least this would be pertinent with space exploration. Earth exploration could allow for "recharges." Of course, if it takes it 3 months of time to get its data...then I feel it would be well worth it. On Earth though, as opposed to Europa, it might still be worth it but I see little use to such things unless they are somewhat fixed in later models.
  • ...is a probe that lands on the planet, drills a hole, and then dangles a hula popper. [geocities.com]
    that will prove if there is life on europa.
    have it bag up what they catch and blast off the surface again!

  • Gliding torpedo (Score:3, Interesting)

    by John Jorsett ( 171560 ) on Wednesday April 10, 2002 @04:23PM (#3319452)
    I knew a Navy engineer who wanted to make a gliding torpedo. It would be slow, but so quiet that it would be undetectable. He also thought that it could be programmed to hold a ship 'hostage', poised just beneath it and set to detonate if the ship changed position. Don't know if anything ever became of his ideas, but they were interesting.
    • This is the kind of unintended thing our increasing abilities re: engineering and computing lead us to. For instance the al Qaeda could get build a gliding torpedo and program it to go after an LNG tanker in a harbor. Given the efficiences, the gliding torpedo could be launched hundreds of miles away off a beach or a trawler and blow your harbor to hell. Several nations could use it and it would be difficult to trace back to the origin ship.
      • I was thinking this exactly. I was picturing something more like an atomic bomb on one of these gliders guided by GPS to blow up right under the Bay Bridge. Needless to say, any evidence about who sent the thing would be vaporized in the blast. (How many nations in the world hate the US?) It could even be in the shape of a dolphin, so it would be very hard to detect en route.

        As I've always said, it seems the best long-term defense against terrorism is for the US to play fair with the rest of the world. Until we do, we're all at risk.

        • Playing fair? Hmmmmm, there are fanatics of all stripes (any -ism you care to mention) that would like to take down the US without regard to American life or property. Playing fair is unlikely to deter such persons.

          What I could agree with is that we need to 'play fair' in terms of working with nations and peoples, not boss them around like they are the hired help, or leaving them to rot with people we prop up for convenience, profit, or emotional appeal. That way we keep 94% of the world at least neutral towards us, then we can squash any -ism that is thinking about coming after us without having to fight the whole world.

  • But how do we get data back? (Score:3, Insightful)

    by Dr. Spork ( 142693 ) on Wednesday April 10, 2002 @04:26PM (#3319485)
    It's all well and good to go on long missions under the Europa ice crust, but if this is expected to be of any use to science, there must be a way of getting data back to Earth. I doubt we could equip this thing with a radio powerful enough to send data through potentially miles of water and ice. The original plan for the battery+propeller vehicle was to have it tethered, IIRC. Would this work in the same way? The cooler thing to do would be to let it go free but then returh and report to a base station (or maybe interface with a cable hanging down from the base station into the water.) The base station could then relay the data back to and orbiter and then on to Earth. Anyway, I think this could be the real technological challenge. Even if you can move far on a "penlight battery" you can't send much of a signal with one.

  • All they really need... (Score:1, Interesting)

    by Anonymous Coward
    All they really need to do is land and sample the ice. If there is life under the ice, and there is a turnover of water onto the ice as I have read, then there will be evidence of life in the frozen water on the surface.
    This would be much easier to do than getting a sub through the ice - if it turns up positive we can then go for the sub.

  • one of the cool.... (Score:2, Interesting)

    by greymond ( 539980 )
    on of the cool things about having being in a country persueing military operations (war on terrorism) and having a rocky market - is all the cool gadgets we get out of it - just think of all the cool stuff that was invented during ww1 and ww2 (good and bad there was still alot of neet stuff)
  • Why is the government paying for this research? I don't see any tactical advantage to beeing able to explore the oceans of Europa. Space research is important, but shouldn't it be privately funded? There are more important things that the US government should be spending OUR money on.
  • If I had to design one of these Europa divers, I fear I would make it have a radioactive decay drive. Basically, it would have a super decay-resistant shell (that we could recover in the far future, before it decomposes) and a bunch of radioactive stuff on one end. That end would get heated and produce thrust. You maneuver with changing the shape of the craft, or with moving around the heat source inside. The heat could also power a computer and a radio to send out data.

    I know it doesn't sound right to send a bunch of Plutonium to Europa (the Monolith warned us...) but we could shield it reasonably well. Once its mission is done, it could use its internal heat to melt upwards through the ice and onto the surface. There it would be isolated from the Europa ocean (the ice would re-freeze below it) and sit in a little warm puddle waiting for someone to pick it up (in, say 200 years).

    This solves a problem which the other posters have already mentioned, namely that even if we send anything else which is on the drawing board, there would be no plan to get it back. It would decompose in the Europa ocean and potentially cause a lot more environmental destruction than just a couple of gamma rays.

    • "I know it doesn't sound right to send a bunch of Plutonium to Europa (the Monolith warned us...) but we could shield it reasonably well."

      How does contamination by plutonium compare to the intense radiation belts that already exist around Jupiter?
      • Yeah, I asked myself this too. But because the answer was "I don't know" I didn't mention it in my post. In any case, I suspect that not much Jovian radiation can penetrate under the Europa ice. Still, I don't think a Plutonium drive would be a big deal. If there is life in the Europa oceans, it is probably very close to the density and composition of saltwater (as are we). This means that the chance of a gamma ray (that penetrates the shielding) hitting a lifeform there is exactly the same as the % of volume in the Europa ocean occupied by life. I assume this is very small indeed.

    • Re:I Want a Plutonium Drive (not kidding) (Score:1, Informative)

      by Anonymous Coward
      The only way to get a satellite there is a nuclear power source - the amount of energy from the sun that reaches Europa is very low (hence, all of our deep-space stuff has had a radio-thermal power source). The problem with the nuclear power sources 'melting' (actually, at the temp/pres. on the surface of Europa, water will sublime) has been studied. As I recall, the approximate depth of entry is on the order of tens of meters (worst case, more or less) after a catestrophic containment failure on the surface. The ice shell on Europa is predicted to be between 1-10km thick, so there's no real contamination problem there. That's actually one of the nice things about the NASA design - with the umbilical cord, your power source could remain on the ice surface (with your transmitter), and not risk contaminating the postulated oceans below, not to mention the fact that your datalink between the swimmer and the transmitter is nice and easy. The real problem with working on Europa is the harsh EM environment (particularly for the vehicle traveling there). The EM fields from Jupiter at that distance are extreme, and will give you a mission life on the order of a month or so (starting from the time you're in orbit, and remember you've got to melt/dig/whatever your way through a kilometer or more of ice)...

      • I wish I could moderate on this topic, but I already posted. Thank you for helping me understand this. I guess I knew about the EM troubles for the inner Jovian moons, but I didn't really put all this together. It really pours cold water (ha ha) on the idea that some fancy free-ranging submarines could ever get any data back to scientists.

  • I can just imagine fleets of these long tube like gliders deep in the ocean, programmed to travel to a specified GPS location for pick up. They could carry huge ammounts of drugs! This will be the DEA's new nightmare.
    • That was my first thought as well. This sounds like it opens up the way for vehicles that would be extremely difficult to track. What's the DEA going to do? Kill all the dolphins? And if you're loading it with a supply that costs pennies to produce under friendly political circumstances in the Mideast or Southeast Asia like meth, ecstacy or hash as opposed to agirculturally intensive products like coke or heroin and if your topredo mules only cost a few thousand dollars to fabricate with negligible operating costs, then you don't care if three quarters of the shipments never make it. A few dozen twenty pound deliveries of meth, X or hash that made it safely could easily pay for a fairly large fleet of roughly made sea gliders.
      They woudln't have to be used from across the ocean, of course. Just bring them a thousand miles off shore in fishing boats and launch them into a known current.
      The GPS could be used quite sparingly in such a scenario, if at all.
      The glider arrives, places a single phone call to a pick up crew before submerging to the shallow bottom and firing off a C02 bouy from that rear compartment where the ballast is. A small fishing boat comes around and brings up the glider by the bouy, extracts the contents, ditches the glider and on the way back to shore the fishermen drop the dope wrapped in a neoprene sheet that looks like a wetsuit and makes it float. It's picked up by a surfer. As the surfer comes to shore, he's already got his wetsuit off and rolled into a bundle casually tucked under his arm. Voila! Heck a wetsuit filled with water is probably coming close to twenty punds anyway. It could look quite natural.
      Obviously too much James Bond lately. It's somewhat plausible though.
      Or how about a huge sea glider filled with tons of weed in waterproof individual one ounce containers that just popped open on a crowded beach like Pacific Beach in San Diego or Santa Monica. No strings attatched, a goodwill mission from the Commuist Party of Mainland China That's even less plausible, but much more fun to imagine.
      Or no, thousands of topless Thai prostititues in G-strings doing nasty dances to pirated MP3s. No, wait. That wouldn't work.

  • Pink Seagliders (Score:3, Informative)

    by Freedryk ( 117435 ) on Wednesday April 10, 2002 @04:48PM (#3319627)
    These things kick ass. I'm a grad student at UW in Oceanography--the pink seagliders in the second picture are built two floors below where I am typing. They're amazing--they communicate home with a cellphone antenna, and there's a 386 laptop connected to a phone line down the hall that accepts their dial-up connections. This allows them to upload their data and recieve new instructions for their mission. Currently they just have a conventional phone on-board for testing, but that will hopefully be upgraded to something like the remains of the Iridium network for the real version.
    They are the result of an amazing confluence of technologies--low-power cpus, which turn on something like once every five minutes to check their situation and take a measurement, temperature and salinity probes that give reliable data without calibration for a year, battery packs, cellular communication, GPS. The great application for these, however, is not to other worlds--it's to our own. In a few years, it is hoped that there will be a global array of automated seagliders and buoys taking temperature, salinity and velocity measurements everywhere in the ocean. Basically, it will be used to construct a global climate monitoring system--something we'd never be able to do without low-power computers and sattellite tech.
    • And hence the need for surefire eco-friendliness. We have done so much damage to sea creatures (think of the wales when we tested nukes underwater) and ecology that if these things are sent out in the ocean en masse to sample the environment, they had better well not damage it.

      I am looking forward to the day that we begin to model the global climate based on empiracle data from this monitoring system.

  • Comment removed (Score:3, Interesting)

    by account_deleted ( 4530225 ) on Wednesday April 10, 2002 @05:55PM (#3320008)
    Comment removed based on user account deletion
    • Read the fscking article please ;p
    • Your ideas intrigue me, and I wish to subscribe to your newsletter.

      "Underwater gliders work by being buoyantly nearly neutral while near the water's surface, so that they sink slowly down. Very slowly - full steam ahead is under one knot. As they sink, an internal weight is shifted toward the lateral direction the vehicle should go - if you want to go straight, just shift the weight forward to tilt the nose down a bit. Then to rise, pump an oil contained inside the hull into external sacks - this simple maneuver increases the craft's volume, and thus lowers its density just enough that now the surrounding water wants to push it upward."

      (quote from the article)
    • uh, for this we'll have to resort to the fourth rule of thermodynamics: you don't getting anything for free (if you can't tell, I made that up, but it's still true).

      The work you do to expand or contract the bladder is the same (or less efficient) as that that would normally propel the sub.
  • There's still the matter of the delivery system, they still have to drill through ice to get to the water below.
  • Correct me if I'm wrong (like I have to ask :-) but it hasen't been proven that there are actually liquid sea under Europa's icy surface has it? It's plausible, maybe even likely, but not certain. So maybe we're jumping the gun a bit here with all this ultra-cool betteryless glider talk?
  • So maybe we're jumping the gun a bit here with all this ultra-cool betteryless glider talk?

    We are never jumping the gun when it comes to something ulta-cool. You build something for the sake of ultar-coolness. Forget practicality, if more stuff was done simply for the cool factor the world would be a better place.
  • Now if we could only get cars that run like that!?
  • The concept of using "rotors" (I guess those would by gyroscopes right?) inside the craft as a means of maneuvering reminds me of the alien craft from The Abyss. They had those weird spinning pieces inside them and not much else.
  • Did anybody consider that if there is any life on Europa that it could be highly evolved.

    A Deep One could be waiting down there for a nice tasty morsel in the form of an Earthlings glider.

    mmm. tasty inflatable sacks, just what I needed...
  • If we could replace the 7x7 missle planes that we ride in with underwater vehicles, that would be cool. -Israel
  • ...and one already exists that could "fly" under the Pacific from Seattle to Tokyo on a penlight battery!

    And how long would this take???

    BTW, anyone have insights as to how "wings" work in incompressible fluids such as water? Do you get the same pressure drop from increased velocity above the wing as you do in air? Though a compressable gas ballast is usually the prefered method of producing 'lift' underwater, could you forgo lighter-than-water substances within the hull of an underwater vessel in favor of using "wings?"
    • My understanding is that in most applications, including aircraft, racing cars and sailboats it's not so much producing lift from the bernoulli(sp) effect as producing lift from the angle of attack of the wing.

      • It has long been debated which effect is more prominent with air as the fluid. Introductory textbooks on aircraft airodynamics tend to state the pressure differential as the cause of lift; while in practice, it many times is more so an effect related to the attack angle - true.

        Don't believe everything you read - even if it comes from a textbook [nasa.gov]. Check out the link for an interesting JavaApplet!!! Pretty neat.

        Good point though. I'm sure attack angle would be even more prominent with water. I was just curious if non-compressable fluids do the same as compressable with a wing-type configuration (as far as the pressure differential goes).

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