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NASA Space Science

NASA Craft To Leave Vesta Heads For Dwarf Planet Ceres 116

Posted by samzenpus
from the moving-to-better-quarters dept.
DevotedSkeptic writes "NASA's Dawn probe is gearing up to depart the giant asteroid Vesta next week and begin the long trek to the dwarf planet Ceres, the largest object in the asteroid belt. The Dawn spacecraft is slated to leave Vesta on the night of Sept. 4 (early morning Sept. 5 EDT), ending a 14-month stay at the 330-mile-wide (530 kilometers) body. The journey to Ceres should take roughly 2.5 years, with Dawn reaching the dwarf planet in early 2015, researchers said. 'Thrust is engaged, and we are now climbing away from Vesta atop a blue-green pillar of xenon ions,' Dawn chief engineer and mission director Marc Rayman, of NASA's Jet Propulsion Laboratory in Pasadena, Calif., said in a statement. 'We are feeling somewhat wistful about concluding a fantastically productive and exciting exploration of Vesta, but now have our sights set on dwarf planet Ceres.'"
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NASA Craft To Leave Vesta Heads For Dwarf Planet Ceres

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  • Good luck Dawn (Score:5, Insightful)

    by symbolset (646467) * on Sunday September 02, 2012 @07:07PM (#41209251) Journal

    We're all counting on you...

    Seriously though, Ceres is an awesome target and much more exciting than Vesta. Vesta is a rock. Ceres is half water ice by volume, in low g. Obviously some serious upside potentials there. A vastly superior target to Mars, or just about anywhere else in the solar system.

    • by c0lo (1497653)

      We're all counting on you...

      ...Ceres is half water ice by volume, in low g. Obviously some serious upside potentials there. A vastly superior target to Mars, or just about anywhere else in the solar system.

      Upside potentials? Care to expand a bit the topic?

      • My guess is that he's talking about possible colonization targets. It's much easier to just 'mine' water at the place you've just colonized, instead of hauling it in.

        • Re: (Score:2, Informative)

          by Penguinisto (415985)

          One tiny problem with that, though: Ceres is a bit further out from the sun than Mars... as in way the hell out there. [wikipedia.org]

          It does have potential for fueling an orbital colony or, well, any colony that isn't at the bottom of a big gravity well. OTOH, if Mars is a screamer of a target to hit, I can only imagine what it would take to hit a relatively microscopic-sized target that's way further out, and somewhat surrounded by asteroids.

          Sounds like fun, though.

          • by mbone (558574)

            One tiny problem with that, though: Ceres is a bit further out from the sun than Mars... as in way the hell out there. [wikipedia.org]

            It does have potential for fueling an orbital colony or, well, any colony that isn't at the bottom of a big gravity well. OTOH, if Mars is a screamer of a target to hit, I can only imagine what it would take to hit a relatively microscopic-sized target that's way further out, and somewhat surrounded by asteroids.

            Sounds like fun, though.

            Should be no problem, especially once Dawn gets there and nails down the orbit.

            Note, however, that there is plenty of water on Mars, a good deal of it accessible from the surface at the poles.

            • Re:Good luck Dawn (Score:5, Informative)

              by symbolset (646467) * on Sunday September 02, 2012 @10:27PM (#41210129) Journal

              Mars has water. A lot of it, right on the surface. Plenty to provide air and water for indefinite human habitation and fuel for the return trip, if you have the energy. That's the good news.

              Mars also has a lot of gravity (.38 g). And it's the gravity that's a killer because it's not got enough atmosphere for a decent atmospheric brake. To land a significant (20 ton or better) craft on Mars in condition to lift off again demands that you set her down on the jets, and that is a very unforgiving process that costs a metric boatload of fuel. Whatever source of energy you use is going to have a lot of mass too. The 1 ton of Curiosity is actually as much mass as we can land on Mars right now. To get humans there in any condition to start a colony requires a vast quantity of fuel to shorten the trip and to land. And where are we going to get that fuel? Ceres!

              Mars has too much gravity to be a good source of water for fuel in microgravity. You have to burn too much fuel to get it off of Mars. As it is on the return trip the humans are going to have to meet up in Mars orbit with a return booster fuelled by LH2/LO2 from Ceres.

              Yeah, Ceres is a good bit further out and it takes longer to get there (to the GP). But the robots don't care. Planetary Resources should get us enough Near-Earth asteroid water to make the fuel to lift the craft out of LEO and send it swiftly on its way to Ceres. At 0.03 g, the water comes off of Ceres nice and easy. Once it comes back to lunar orbit (firing its LH2/LO2 jets) with its kilotons aquatic payload a lot of other things like Mars become realistically possible. There are just not enough near-Earth asteroids of the right type to provide the supply we need for this.

              Ceres is the key to everything. If it really has the water.

              • What if you where to crash Ceres into Mars for the purposes of transforming.

                Would that provide a large quantity of surface water/ice for Mars, more than the oceans on Earth, the dust and heat from the collision may even help to establish a thicker atmosphere and raise the surface temperature.

                Thats 10^21 kg of mass to that needs to be reduced in orbit by 1AU , it sounds a lot, but all you would need is a rather strong space elevator type cable, some rechargeable fuel efficient ion engines, proper calculation

          • by shaitand (626655)

            My guess is he's talking about finding life.

        • Re:Good luck Dawn (Score:4, Interesting)

          by symbolset (646467) * on Sunday September 02, 2012 @11:34PM (#41210427) Journal

          Colonization of Ceres requires that the humans live in a huge centrifuge because humans don't bear up well under such a tiny gravity in the long term and centripetal force is a fair substitute. Construction of such a centrifuge on Ceres would require considerable resources we don't have because Ceres has both significant gravity and spins on an axis. Ultimately a human habitat on orbit of Ceres seems more likely to me than one burrowed into the ice for this reason, as the centrifuge is simpler on orbit. In fact, the operation of human habitat polar centrifuges would alter the poles of Ceres and be self-defeating. But given such a habitat on orbit, short-term surface ventures and shelter from solar storms are trivial with a surface gravity of 0.03 g and unlimited available fuel from refinery operations. A space elevator on Ceres though, that would make better sense than anywhere else in the solar system.

          No, I'm excited about Ceres only as a source of water for LH2/LO2 fuel, O2 for breathables, water for drinking, minerals for refining and fabrication - not as habitat. It may be 50 years or more before we put people there and that will be out of scope for me.

      • by mug funky (910186)

        i'm guessing it's about potential fuel for even further expeditions.

        take a 50/50 rock/ice object and a "sufficiently advanced probe", you can extract aluminium from the rock, make nanoparticles, then use the ice with the nanoparticles as a rather powerful thermite style propellant.

        or just make a shirtload of liquid H2, but that's possibly a bit more energy intensive.

        • by jamstar7 (694492)
          Or crack the ice down to hydrogen and oxygen, you know, that stuff we breathe? With plenty of solar energy, it shouldn't be a problem. Where there is water, there can be life, even if it lives in a habitat. Bonus if the ice is 'dirty', contaminated with various hydrocarbons. They'd make great feedstocks and precursors for your plants and animals.

          Hell, sign me up!!!
      • Re:Good luck Dawn (Score:4, Interesting)

        by symbolset (646467) * on Sunday September 02, 2012 @09:43PM (#41209961) Journal

        Space is cold, and dry. It can be pretty hard to find water out there, and gas stations are far between.

        Planetary Resources [planetaryresources.com] is a company in Seattle set up to mine asteroids. The big deal at first is asteroid-borne water, which comprises up to 30% of some asteroids. They are going after asteroids that pass near the Earth at first.

        The big deal is what potentials this opens up for expoloration of our solar system and the stars. With energy water can be converted into LH2/LO2 fuel. The problem is that lifting up the fuel from our deep gravity well makes this prohibitively expensive.

        Ceres may have 200 million cubic kilometers [wikipedia.org] of water ice, almost all of it relatively pure and on the surface, 100km thick. That's more water than all of the fresh water on Earth. Ceres has a surface gravity of 0.03 g, so getting the ice or fuel away from there is no big deal. There may be other volatiles there as well - Xenon would be a great find. We've found water on the moon and Mars, but getting the water away is nearly impossible because the gravity on these bodies is just too high. Small asteroids aren't plentiful enough for a huge explosion of exploration and manned habitation in space.

        Abundant water and energy are the two essential keys to human and robotic exploration of the solar system. If we can somehow with robots bring energy and equipment to this ball of water we can bring back enough fuel to scoop much larger payloads out of much cheaper near Earth Orbits and move them anywhere from there. That enables larger habitations with centrifugal simulated gravity, water ice mass shielding from radiation, million-kilo LH2/LO2 rockets that start in microgravity and so don't have to spend 90% of their fuel lifting up out of our gravity well.

        Ice makes a great construction material too, so if we found a way to put humans on Ceres they need not worry too much about radiation or building materials. It's also a great thermal insulator, and we've learned how to carve habitats out of ice in Antarctica.

        In short if that water is really there it is the key to humans establishing a permanent occupation of space, and maybe the fuel we'll use to send the first probes to nearby stars. We'll know in about 30 months.

        • by c0lo (1497653)

          Abundant water and energy are the two essential keys to human and robotic exploration of the solar system.

          I can see the water on Ceres, the energy part is a bit tricky.
          - Mars-Sun distance - varies between 1.38 AU and 1.66 AU (say 1.5 AU as an average)
          - Ceres-Sun distance - varies between 2.55 AU and 2.99 AU (say 2.7 AU as an average) With a variation of of irradiation going with the inverse of square distance => a unit of surface on Ceres receives 3 times less energy from Sun then the same area on Mars. Same calculation knowing that the solar constant for Earth (1 AU) is approx 1 kW/m2 results in a 137 W

          • by WCguru42 (1268530)

            Same calculation knowing that the solar constant for Earth (1 AU) is approx 1 kW/m2 results in a 137 W/m2 on Ceres (put on top of it the 20% efficiency of a photovoltaic and you'll get... what... 27 W/m2?)

            Isn't part of the 1kW/m2 on Earth due to the atmosphere absorbing some of the energy? Ceres wouldn't have that problem. Still, that distance-squared reduction would still create issues.

            • by c0lo (1497653)

              Same calculation knowing that the solar constant for Earth (1 AU) is approx 1 kW/m2 results in a 137 W/m2 on Ceres (put on top of it the 20% efficiency of a photovoltaic and you'll get... what... 27 W/m2?)

              Isn't part of the 1kW/m2 on Earth due to the atmosphere absorbing some of the energy?

              Yeah... [wikipedia.org] - my lazy ass didn't want to be too exact: the solar constant as seen by a satellite is approx. 1.36kW/m2. Which means on Ceres it would be 186 W/m2.

              Ceres wouldn't have that problem.

              I wouldn't be so sure: it can actually be worse due to the water subliming [wikipedia.org] at "day" time (a "haze" which would create an absorption - mostly in IR and UV) and condensing back at night time.
              Now, if the sublimation/condensation process is not energetically balanced - and because the PV "steal" some energy it is definitely not balanced, thus the condens

            • by symbolset (646467) *
              Insolation is a serious issue. It would be necessary to either use nuclear power, or first move the water closer to the sun before converting it to fuel with solar power. On orbit around Ceres the unfiltered solar energy is only a little less than on the Sahale in summer, and that is not nearly enough to do the job in a reasonable amount of time. It takes a LOT of energy to convert water to its constituent elements and then liquefy the proceeds. Think of LH2/LO2 as more of an energy storage medium than
          • by symbolset (646467) *

            Very good question. Yes, we are likely to use nuclear energy for this. Remember, the plan is to lift it only to LEO, and use the Hydrox from Planetary Resources to lift it higher and send it to Ceres. Nuclear fuel is a high-density, high-value cargo and we'll need quite a lot of it. To fully exploit Ceres' water resources would deplete the entire world's available nuclear weapons and some fraction of nuclear waste from power production, and then some. Convenient, no? We were done with that stuff here

    • by Anonymous Coward

      I'm not convinced Ceres is particularly useful as a destination. I guess I'm just not American. The ESA has given the go ahead to the only mission to interest me since Cassini Huygens - the JUICE mission to explore the moons of Jupiter, and in particular it's focusing most of its interest on Ganymede - the largest moon in our solar system, with its own magnetic field - just like Mercury. If I was going to bet on life being found in our solar system, maybe even complex life - Ganymede would be my bet. I hone

      • As this image [wikipedia.org] makes clear, Ganymede's magnetic field protects only the equatorial latitudes from Jovian radiation. The rest of surface is bombarded with heavy ions, although the surface radiation levels are admittedly much lower than on Io or Europa.

        If life were to exist there, it would probably be in the subsurface oceans (as with other candidate moons) where the presence of the magnetic field is of less importance.

        • by Dr. Spork (142693)
          Exactly, and there wouldn't be much point to humans living in some under-ice ocean, just to be able to say "Gee whiz, I'm actually living on Ganymede! Look at me here, living!". There are many more places for us to live under the sea on our own planet. Yes, that sounds stupid, but us living on any other planet - with the possible exception of Mars - would be even more stupid. But there are "sky is falling people" who think we will screw up the Earth, and will only survive as a species if we move to space. T
          • Re:Good luck Dawn (Score:4, Interesting)

            by symbolset (646467) * on Sunday September 02, 2012 @10:45PM (#41210191) Journal

            This is an interesting point. A sufficiently deep subsea human habitat that was self-sufficient might be enough to preserve mankind against even a planet-killer asteroid, if it survived the initial shock wave. Certainly many aquatic species survived the last dinosaur killer, including sharks. If you put it at the equator it should be safe from ice ages. Geothermal energy would be persistent enough, even if the uranium from seawater thing didn't work out. It would have to be a subsea city with pop > 100k though to provide a persistent level of science and culture.

            There's probably a good trilogy of books in this one if you want to develop it.

            Not proof against nuclear war though. If I know anything about my fellow men, they're griefers and when the shit hits the fan a subsea survival habitat is going to have several torpedos with its name on them, some of them nuclear.

            • by Teancum (67324)

              As much as the notion of aquatic habitats may seem romantic, the engineering requirements for sustained deep sea habitation are in some ways much more extreme than even going to Mars or the Moon. Keep in mind that the pressure going underwater doubles after just a few feet. Going from sea level to the Kármán line in altitude only has a drop of about 1 bar of pressure. Since that is practically zero, it can't get any worse. If you go diving just a few feet deeper, depending on where you are at,

              • by khallow (566160)

                Surface seasteading, on the other hand, seems to be very promising in spite of the fact that nobody has really been successful at doing that with 21st Century technology.

                They've been successfully doing it since ancient times. The current very successful model is seasteading by ship with occasional stops in specialized structures called docks and harbors.

                • by Teancum (67324)

                  Surface seasteading, on the other hand, seems to be very promising in spite of the fact that nobody has really been successful at doing that with 21st Century technology.

                  They've been successfully doing it since ancient times. The current very successful model is seasteading by ship with occasional stops in specialized structures called docks and harbors.

                  While a few people do seem to live their lives almost permanently aboard ship, they really are transportation devices to get you from one place to another and not a place where civilizations form and act independently.

                  There really is a difference between a ship and an island or city. There is also the difference between a spaceship and a settlement in space as well, even though you can build a city in the middle of the ocean just as much as you can build a city in some random spot in space.

                  I think it could

                  • by khallow (566160)

                    While a few people do seem to live their lives almost permanently aboard ship, they really are transportation devices to get you from one place to another and not a place where civilizations form and act independently.

                    Even so, they're seasteading examples. And some of the most profound changes in society have come from ships such as the voyage of the HMS Beagle on which Charles Darwin made the observations that became the theory of evolution, or any number of decisive sea battles (such as the battles of Midway, Jutland, or Salamis).

                    • by Teancum (67324)

                      Even so, they're seasteading examples. And some of the most profound changes in society have come from ships such as the voyage of the HMS Beagle on which Charles Darwin made the observations that became the theory of evolution, or any number of decisive sea battles (such as the battles of Midway, Jutland, or Salamis).

                      Jared Diamond has gone so far as to assert the development of modern mankind and civilization as we know it today originated from the evolutionary pressure from long distance sailing. Certainly the ability to navigate across the ocean is an evolutionary pressure for increased intelligence.

              • by symbolset (646467) *

                Surface seasteading doesn't protect us against an asteroid or nuclear war. It's an interesting social solution to other problems, but it doesn't address the whole "We're all going to die" thing. I'm all in favor of it for the benefits that you present, but it doesn't address the core issue in this discussion. An asteroid hit wipes it out. A nuclear hit wipes it out. It's not a backup plan.

                It's an interesting segwey I'd like to see have its own discussion, but it's out of place here.

              • by symbolset (646467) *
                The advanced technology I need to preserve atmosphere at any reasonable depth is called a "cup".
                • by Teancum (67324)

                  The advanced technology I need to preserve atmosphere at any reasonable depth is called a "cup".

                  Or so people used to think, including John Roebling [wikipedia.org] when he was building the Brooklyn Bridge in New York City. Unfortunately the workers on that bridge developed something called Caisson Disease [wikipedia.org], named after the affliction first significantly noticed by the workers who died building that bridge in NYC. In fact Roebling himself died from complications of decompression sickness as he entered the cassion regularly to check on the progress of the workers.

                  There are numerous health problems with using a cup lik

                  • by Trogre (513942)

                    You'd best update John Roebling's Wikipedia page then, since it states that he died from tetanus that arose from having his foot crushed by a ferry.

                    In fact, you could say he experienced a sort of compression sickness :)

          • by Legion303 (97901)

            But there are "sky is falling people" who think we will screw up the Earth, and will only survive as a species if we move to space.

            I've never heard of a single person who wants the species to get into space because he's worried about humans screwing up the planet. I have heard of many, many people who want us to get into space because of the odds of another asteroid strike destroying most of earth's life again.

      • by symbolset (646467) *
        Jupiter is twice as far out from the sun as Ceres, meaning that it's usually almost three times as far from the Earth at closest approach. Coming away again is harder too, as surface gravity is 6 times as high. I should think that having a heavy-duty supply of propellant from Ceres or other sources would help get the resources there for proper development of Ganymede.
    • But if we do nail both Ceres and Mars somehow, then we can have the Vesta both worlds. How about it, science?

  • Are they leaving him behind on Vesta? I guess it's about time. Maybe his act will be fresher for the Vestans....

  • by tomhath (637240) on Sunday September 02, 2012 @07:30PM (#41209359)
    This kind of control just amazes me. Orbiting a dinky little asteroid, just amazing.
    • by symbolset (646467) *
      Yes, it really is, even though calling Vesta dinky is a bit of a stretch. It has more surface area than Texas by almost twice. Almost a million square kilometers.
    • by daid303 (843777)

      If you want to feel this kind of control yourself, try the Kerbal Space Program.

  • Vesta flyby video (Score:5, Interesting)

    by Narishma (822073) on Sunday September 02, 2012 @07:39PM (#41209417)

    Here's a cool video [youtube.com] generated from pictures taken by the probe as it orbited the asteroid.

    • Too bad it's just a CGI animation. Around the 0:30 mark you see what looks surprisingly like a coconut with two eyes and the beginings of a mouth or nose. More stuff for alien conspiracy theorists to shake their stick at.

  • Dear Slashdot: (Score:5, Insightful)

    by fustakrakich (1673220) on Sunday September 02, 2012 @08:20PM (#41209633) Journal

    When posting NASA news, it's always best to go to NASA itself [nasa.gov]. Avoiding ad cluttered sites will help reduce excess traffic on our limited bandwidth.

    • by Teancum (67324)

      That mostly depends on the submitter. Next time you submit a story like this, make sure you follow your own advise on this matter. Perhaps eventually it will catch on too.

      • I always go as close as possible to the source of a story* when making a submission... 100% of the time. The editors can do the same before posting the submissions that don't. But they and Google Analytics have a different agenda.

        * short of linking to paywalls and anything that requires registration.

  • When did Ceres become a dwarf planet instead of an asteroid?
  • WHAT. It is a crime, a *crime*, I tell you, that this article doesn't even mention the NASA team's slogan for this phase of the mission.

    http://dawn.jpl.nasa.gov/news/hasta_la_vesta.asp [nasa.gov]

  • Didn't the probe have some flaky gyroscopes or the like a few months ago? Last I read, they risked the entire Ceres mission. Two were malfunctioning, not just one. Haven't seen an update.

    • by Anonymous Coward

      Eh, the second (of four) reaction wheel was shut down due to excessive friction torque; when the first one failed in 2010, they started working on software to fly with only two (+ hydrazine jets, but using much less fuel than hydrazine-only). It also spent most of the rest of the cruise phase with none, using hydrazine jets + gimballing the ion thruster for all attitude control, to save the remaining wheels' wear life for use on orbit at Vesta and Ceres, and will do the same while cruising to Ceres. They al

      • by Anonymous Coward

        I don't know what it is with reaction wheels, but there's a long line of missions where they have been one of the most serious things to fail, sometimes very early in the mission (Dawn, Hubble, FUSE, Hayabusa, Kepler, etc.). It seems like every second mission has unexpected problems with them. I know they are mechanical, mechanical means wear-and-tear, and space is about the harshest environment to operate in, but is it really the case that we've been building these things for 4 or 5 decades and yet early

        • by Tablizer (95088)

          Must be why probes carry a fair amount of hydrazine. It might be one of those things where if it works, it can save a lot of fuel and time and give you more options; but if it doesn't, then have a back-up ready (hydrazine nozzles).

  • NASA Craft To Leave Vesta Heads For Dwarf Planet Ceres Forgets To Include Comma Makes Headline Hard To Parse

    DevotedSkeptic [devotedskeptic.com] writes^H^H^H^H^H^H^H copies and pastes

    And FTFY too.

  • For a visual representation of the mission, download Celestia [shatters.net] and install the Dawn [celestiamotherlode.net] and Vesta [celestiamotherlode.net] addons. Make sure to enable "Orbits" and "Orbits/Labels" for planets, dwarf planets and spacecraft. If you select Vesta (Enter -> type Vesta -> Enter) its orbit will be visible as well. Use the time controls to view the whole mission :)

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