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Space Science Technology

NASA to Research Antimatter Rocket 358

Posted by timothy from the skeptical-until-it-blows-me-up dept.
Fraser Cain writes "One of the dozen technologies selected by NASA's Institute for Advanced Concepts (NIAC) this year is Positronics Research's ideas for an antimatter rocket engine. Instead of 3100 kg of propellant on board Cassini, the spacecraft could get by with just 310 micrograms of electrons and positrons. Of course, making the antimatter can be expensive."
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NASA to Research Antimatter Rocket More

NASA to Research Antimatter Rocket

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  • The problem is that they won't be able to create sufficiently powerful and controllable anti-matter engines until they secure a sufficient supply of dilithium crystals.

    But seriously folks...

    Many of our upcoming challenges both earthbound and space bound relate to the safe, efficient, portable, and inexpensive generation of HUGE amounts of power. Whether it's antimatter, zero-point energy, fusion, whatever, let's get something off the drawing board and into service.

    My laptop is more powerful than a 1975 supercomputer that filled a room, but a D cell battery hasn't changed its size in 30 years and today's best D cell lasts what 2, 3 times as long as one from 1975? We're still running coal-based and oil-based power plants that were built in the '70s. Is everything shooting along while power generation creeps?

    • I say research some zpm tech and lets be done with power generation.
    • Is everything shooting along while power generation creeps?

      Work out the chemistry on it. The simple truth is that unless there is a fundamental change in energy density of chemical reactions, there just isn't a lot more to ask of chemical storage. That's why there is the shift towards "power generation." This is really just a fancy term for changing from where there is a chemo-eletrical differential (i.e. positive/negative sides) to actively causing a chemical reaction that provides electricity; however, there are two problems with this approach. First, it is usually easier to ask the device to use less power. Second, power generation at a minimum produces heat, sometimes violently and excessively. Batteries are nice because they are generally quite safe, reliable, and (most importantly) currently mass-produced.

      On a side note, super atoms seem to be a possibility on "rewriting" our understanding on chemical reactions.

      • Re:But, if I give'r any more she'll explode! (Score:5, Interesting)

        by Rei ( 128717 ) on Saturday July 09, 2005 @06:30PM (#13022953) Homepage
        Yeah, chemical advances are pretty much a dead-end (although there may still be *some* improvement left to go - for example, alane (stabilized aluminum hydride) hybrid rockets) but there's a long way to go before we can just deal with things like antimatter rockets.

        Just ignoring all propulsion-creation issues (you can't just pump the two things together in a reaction chamber, and most of the emitted energy is gamma), when you see statements like this:

        Instead of 3100 kg of propellant on board Cassini, the spacecraft could get by with just 310 micrograms of electrons and positrons.

        It sounds great until you realize that, with conventional technology, those 310 micrograms would require a penning trap weighing hundreds of tons (at best) to store them. We need *far* better storage density in addition to far more efficient antimatter generation.

        Far more near-term is antimatter-catalyzed microfission and microfusion (where you use antimatter to start a fission or fusion reaction in a tiny fuel pellet). For non-antimatter based high ISP propulsion, there are lots of neat ideas - to name a few, solar and magnetic sails, magnetohydrodynamic propulsion, fission fragment rockets, Orion and its successor Medusa, photonic rockets, and one of my favorites, nuclear saltwater rockets (you store an concentrated aqueous uranium or plutonium salt in capillaries, and inject it into a reaction chamber where it reaches critical mass and flies out the back at extreme speeds)
    • Indeed. In space, you live and die by how much power you can generate. Here on Earth we have the Sun to power the whole planet, which can then be distilled down to more power dense forms. That doesn't exist in space.

      What we need is to start using the nuclear fission powered engines that we KNOW work. Whether they be NERVA, Orion, or nuclear powered ION drives, nuclear fission is the best place to start.

    • What's a teeming horde to do? (Score:4, Interesting)

      by lheal ( 86013 ) <lheal1999NO@SPAMyahoo.com> on Saturday July 09, 2005 @06:02PM (#13022828) Journal

      Humans like to find new territory and conquer it. We currently have exhausted the Earth's surface, except for the submerged and frozen parts. So we have to go somewhere.

      That said,

      Many of our upcoming challenges both earthbound and space bound relate to the safe, efficient, portable, and inexpensive generation of HUGE amounts of power.

      Space propulsion may end up being a two-fold operation, with a rocket or rail gun used to break free of the earth or moon's gravity well and a deep-space propulsion unit used for the long haul.

      Something like a solar sail or ion drive might fill the bill. An ion drive is relatively inexpensive, but doesn't give much push. If a chemical rocket or magnetic accelerator gets you started, an ion drive could work nicely.

      You still need "HUGE" amounts of power for a rail gun or rocket, though.

      Feel free to ignore the above. I'm just waiting for an rsync to finish so I can shut down the old server and go home.

      • Re:What's a teeming horde to do? (Score:4, Interesting)

        by ScrewMaster ( 602015 ) on Saturday July 09, 2005 @06:09PM (#13022855)
        Better yet, I say we build a lunar mass driver, and mine the moon for materials to build lots of near-space orbiting infrastructure around the Earth. The mass driver could be powered by solar arrays and would continually launch small packets of ore and other materials towards earth. "Catcher" ships would go out to meet the incoming deliveries and take them where they're needed. Giant solar reflectors could take moon rock and melt it, at which point it could be foamed by gas injection, molded into any desired shape and then used as a structural material.

        Actually, this all came from James P. Hogan's "The Two Faces of Tomorrow". Interesting book from a space-technology perspective.

      • Re:What's a teeming horde to do? (Score:4, Funny)

        by Alsee ( 515537 ) on Sunday July 10, 2005 @02:02AM (#13024863) Homepage
        Humans like to find new territory and conquer it.

        <Bush>
        Well, there's still Iran.
        </Bush>

        -
    • My laptop is more powerful than a 1975 supercomputer that filled a room, but a D cell battery hasn't changed its size in 30 years and today's best D cell lasts what 2, 3 times as long as one from 1975?

      Indeed, how can our civilization advance until everyone is carrying around D-cell-sized batteries that contain enough energy to destroy a city. (Try not to short-circuit them.)

      • Re:Scotty, we... need... more... power! (Score:5, Funny)

        by ericspinder ( 146776 ) on Saturday July 09, 2005 @06:42PM (#13023019) Journal
        until everyone is carrying around D-cell-sized batteries that contain enough energy to destroy a city.
        That's when this converstion would come to pass:
        Farnsworth: "So what are you doing to protect my constitutional right to bear doomsday devices?"
        NRA Guy: "Well, first off, we're gonna get rid of that three day waiting period for mad scientists."
        Farnsworth: "Damn straight! Today the mad scientist can't get a doomsday device, tomorrow it's the mad grad student! Where will it end?!"
        NRA Guy: "Amen, brother. I don't go anywhere without my mutated anthrax. For duck huntin'."
    • Because if a near-free energy source was developed our oil dependent economy would be in trouble. Our supreme overlords would not like that very much.

      There are all kinds of supposed suppressed technology like the free energy magnetic motor. Some are probably fakes but some look very convincing. I'm not an expert in any of this, but it's obvious power technology is being suppressed. Breakthroughs are made every day in technology but strangely rarely in energy research. How else can you explain our cars st
      • I'm not an expert in any of this, but it's obvious power technology is being suppressed.

        If I had an energy source that generated any voltage, at all, at a cheaper cost than what comes out of my wall, you'd better beleive I would use it. And I would likely expand it as much as I could, because once I have my power paid for, then I get to start selling the voltage.

        Energy technology is NOT being suppressed. Unless, of course, by "supprsed" you mean "forced out of the market by cheaper alternatives."

        How

    • Is everything shooting along while power generation creeps?

      It is simply the economics of power. The reason that technology advanced so quickly is that it was profitable to push it along so quickly. Conversely, the reason that alternate energy has not advanced at all is because it is extremely bad on the bottom lines of oil companies.

      If you think Microsoft is hard on it's competitors (or percieved future competitors), just imagine an industry thousands of times larger that is run by people thous

  • If they can make it, good. (Score:3, Interesting)

    by A beautiful mind ( 821714 ) on Saturday July 09, 2005 @05:40PM (#13022675)
    If they could make this work it would cut down the size of the object to be launched drastically. That would be a great thing, which in itself would make spaceflight more profitable. No more 3T fuel, fuel tanks, etc.

  • Containment (Score:5, Insightful)

    by moz25 ( 262020 ) on Saturday July 09, 2005 @05:41PM (#13022680) Homepage
    One of the major problems with antimatter is that you need to be able to contain it very very securely. The actualy weight of the antimatter may be substantially less, but the whole infrastructure to create it and contain it is going to be considerably more complex and expensive.
    • that is where good ole' electromagnetism comes into play.

      • Re:Containment (Score:3, Informative)

        by imsabbel ( 611519 )
        Well, captain obvious...
        Without electromagnetism is would be impossible, but even with it its really damn hard...
        Dont forget: if you wanna store large amounts of anitmatter, you can forget positon only storage simply because of colomb forces... 300ug positrons or antiprotons would ruin any attempts to trap them...
        So you need anti-hydrogen atoms. Doable, but still tricky. Because now, you have to use higher order fields to trap. Something like a penning-trap. Of course now, you can get spin-flips that will r

  • Danger! (Score:3, Funny)

    by Laivincolmo ( 778355 ) on Saturday July 09, 2005 @05:41PM (#13022681)
    Captain! If we can't stabilize that containment field in the next thirty seconds, we're going to have a core breech. Wait... what if we reverse the polarity? Brilliant!
    • haha... I'm also impressed with Enterprise engineer's frequent trick of solving problems by reversing field polarities :) They must have taught it in star fleet academy's engineering 101, "when in doubt, try reversing the polarity". :-)

  • 310 micrograms! (Score:2, Insightful)

    by Anonymous Coward
    It's going to take insane amounts of energy to generate and store that much antimatter. Hopefully this leads to increased funding for particle accelerators though.

  • Expensive to produce (Score:5, Informative)

    by rssc ( 898025 ) on Saturday July 09, 2005 @05:46PM (#13022716)
    According to the Wikipedia producing antimatter is quite expensive. They mention something of $25 billion per gram. [wikipedia.org]
    That's around $7'750'000 for these 310 micrograms...
    • That's around $7'750'000 for these 310 micrograms...
      Considering that a 'cheaper' probe is north of 350 million, 7.5 million just for some really lightweight fuel would be really cost effecient. However, I believe that the weight and cost of the containment for the antimatter is the real issue.
    • Interesting. As a portion of the cost of a launch for a interplanetary mission, that's almost trivial. The overall cost could end up much less if the containment and other technologies don't overly kill the cost.
    • Yeah, and I hope it never gets easier to make and store. Antimatter would be the ultimate WMD - if it ever gets to the point where a small group of whackos could synthesize a gram or two and contain it in a refridgerator-size vessel civilization is pretty much over.

      • Re:Expensive to produce (Score:4, Insightful)

        by Daniel Dvorkin ( 106857 ) * on Saturday July 09, 2005 @09:36PM (#13023782) Homepage Journal
        Honestly, antimatter is no more an "ultimate" WMD than nukes are -- if you blow up a city, it really doesn't matter to the inhabitants of that city that someone did it with antimatter rather than, say, an unaccounted-for Soviet-era nuclear weapon [theregister.co.uk]. The reason I'm not terribly worried about antimatter-toting terrorists is the same reason I'm a lot more worried about terrorists getting pre-made nukes than I am about them building one from scratch: it takes a tremendous knowledge base and industrial infrastructure that is beyond the capacity of even the biggest and best-funded terrorist group.

        Worrying about terrorists with WMD's makes sense. Worrying about antimatter research in that context is just silly.
  • The actual technology of using antimatter to power a drive sounds great, but surely there will be great advances in technology needed to store antimatter in something light enough to make the difference worthwhile. The weight and size of the entire package are something to think about, but this still seems like an exciting direction for things to be going, and one that could perhaps make long distance space travel possible.

  • How much? (Score:3, Interesting)

    by MyLongNickName ( 822545 ) on Saturday July 09, 2005 @05:49PM (#13022745) Journal
    How much antimatter would it take to wipe out all human life on earth? My guess is in the 20g - 5000g range, depending on how it is "deployed". Anyone else have a better clue?

    Why do I ask? Think about nuclear power. We are now worried about radioactive material falling into the wrong hands. Fortunately, we have some detection methods to make it a little harder to deploy. Now if antimatter becomes a common battery source (say SUV's have 1 millionth of a gram to make it run for the week), how hard would it be to make the ULTIMATE terrorist act?

    Granted, the availability of antimatter on this scale won't happen for a few decades, if not centuries. But when it does... it will be interesting...
    • Interesting point. Peter F. Hamilton's "Reality Dysfunction" series examines this to some extent. A far-reaching space opera, one of the side notes is that the intergalactic governments have outlawed antimatter, both for propulsion and especially for weapons, because of how frighteningly powerful and compact it is.

      - Greg

    • More than that... (Score:5, Interesting)

      by ControlFreal ( 661231 ) * <niek AT bergboer DOT net> on Saturday July 09, 2005 @06:03PM (#13022832) Journal

      The upper end of your scale, 5 kg, amounts to E = m * c^2 = 5 * 9e+16 = 4e+17 Joules.

      The Russian Tsar Bomba [nuclearweaponarchive.org] ---the World's largest nuclear weapon ever detonated on Earth--- yielded 50 Megatons of energy, or about 50e6 * 4e9 = 2e+17 Joules.

      That bomb didn't kill us, so 5 kg of antimatter won't kill us all.

      To put things in perspective, the Hiroshima bomb (15 kton) destroyed about 1.5 grams of matter. The Tsuami quake on the Pacific, last year, yielded about 30 Gigaton [esgindia.org], or 6.4e+19 Joules. That amounts to about 600 to 700 kg of destroyed matter.

      • Thanks for the information and the links. Some interest. I'd figured the upper end of my scale would be good for a single bomb released from the air... concussion would wipe out life. From the Tsar Bomba link, I see I was wrong.... maybe by a couple orders of magnitude.

        So, I can sleep better knowing that a terrorist couldn't destory the earth with something that could fit in his pocket... he'd need at lease a U-Haul to make that happen.... end what are the odds of that? [mit.edu] :)

      • One small mistake (Score:3, Informative)

        by kf6auf ( 719514 )

        You made a minor mistake in your E=mc^2 math. The mass you use should take both the antimatter and the matter into account because any given matter-antimatter reaction involves the conversion of matter and antimatter into pure energy. This results in 10 kg being converted into energy, or about 10^18 Joules or 125 megatons.

        And in case you were wondering if the other poster that claimed bad math was right or not, he's wrong. The correct units are J=kg*(m/s)^2 like parent used.

    • 1. Technology -- use of tools -- defined and shaped humanity, and still does. If we turn away from new technology because we fear we might use it inappropriately, then we might as well forget how to make wheels and fire and join the other primates sitting in the forest eating grubs and taking up space.

      2. Any advanced propulsion technology, including antimatter, is likely to be deployed only in space, not on vehicles launched from Earth. Manufacturing facilities could be base off the planet, as well.

      3.
      • 1) I never said don't pursue the technology.... Just a weird thought about its potential use. Certainly you are not advocating that we don't thing of how the technology could be used by someone, are you?

        2) You might be right. You might be wrong :)

        3) I was just making up a scenario where anti-matter might be obtainable by the average person... not planning on pantenting anything... I was just thinking about how big we could make our SUVs if we had a cheaper power source :)

  • Expensive isnt even beginning to descripe it.... (Score:5, Interesting)

    by imsabbel ( 611519 ) on Saturday July 09, 2005 @05:49PM (#13022746)
    Without so much more technological breakthroughts (who will of course make that whole project pointless, because totally new options would arise), building a antimatter rocket will be impossible.

    First: containment-> Its hard getting long livetimes in a nice good storage ring that doesnt suffer massive accelerations and other nasty stuff launching from earth brings with itself.

    Second: containment part two: To power it, you would need a energy source of such capacity that could feed an ion drive or equivalent just fine without the need for antimatter.

    Third: containment part three: if it fails it will give the a real nice flash. ok, with such a small one this doesnt matter (a normal rocked exploding is also devastating, but a bigger one would be like a nuke on steroids).

    Fourth: Production of anitmatter: current efficiency of antimatter creation is somewhere around absolute zero... dont know the the exact numbers (the article was a few years old), but with current technology it could very well take the energy production of the whole USA to create that much anitmatter... for a year or so...

    All those points dont mean that it wont be possible (or even desirable) to build an antimatter engine, but the needed advancements are THAT far away, that every kind of basic studies now are pointless.
    • >Third: containment part three: if it fails it will give the a real nice flash.

      No matter what kind of rocket it is, it has enough stored energy to put its payload into orbit.

      For any given amount of payload, an antimatter rocket is actually going to be lighter than a chemical rocket. It doesn't have to carry the weight of chemical reactants. It doesn't have to lift that weight. Same payload, less total energy.

      Best of all, gamma rays don't travel very far in air, so as long as you maintain the same rang
  • Of course, making the antimatter can be expensive.

    Shouldn't that be explosive? Or did I missed something when learning my Star Trek science [nasa.gov]?
  • In terms of destructive power, it's actually a lot less dangerous than you'd think: http://en.wikipedia.org/wiki/Antimatter_weapon [wikipedia.org]
  • As a public service I am creating this thread for the purpose of containing all the inevitable Star Trek jokes. Please do your part by getting them out of your system here. Thank you.
  • Why is Slashdot even reporting this? "One of the dozen technologies selected"... Wake me up, when there is a prototype... Heck, a blueprint of a prototype...
    • Blame the title, and the editor that let it pass. I tried to tell them before release that it was wrong.

      NASA will not research anti-matter rockets. NIAC (http://www.niac.usra.edu/ [usra.edu] will fund an external investigation. This is the kind of thing that NIAC (NASA Institute for Advanced Concepts) does. They foster the dreamers.

      It's very intersting stuff, but it's PRE-vaporware. It's not even a study yet. It's a brainstorm on paper to find out if the idea is worth making a study out of.

  • hard to make (Score:5, Informative)

    by n0mad6 ( 668307 ) on Saturday July 09, 2005 @06:01PM (#13022820)
    Speaking as someone who uses antimatter every day, I have to point out that at least now, antimatter is very difficult to make. We expend 100,000 protons (ones that have been accelerated to very high speeds) to make one anti-proton. They get "stored" in a large accelrator complex underground (much bigger and bulkier than a spacecraft). After about half a day of this, we produce about a hundred thousandth of a microgram of antiprotons (which we then smash the hell out of).
  • They say that a couple hundred micrograms of antimatter contains about as much energy as 3100kg of fuel, right? So what's the difference if either one explodes? Well, brushing aside the higher reaction speed of antimatter/matter and the random radiation flying around...

    Containment of positrons is also *super* easy. Just use a Penning trap - a big magnet and two electrodes. And you could make it so small that it would be virtually indestructible. It would really be much safer than a giant fuel tank wit
    • Confinement of positrons is certainly straightforward in a Penning Trap. Unfortunately, the Brillouin limit means the total mass-energy of the stored positrons is always at most the stored magnetic energy of the magnet used in the trap.

      This is completely inadequate for prpulsion purposes.

  • Storage, not production, is the problem (Score:4, Informative)

    by pfdietz ( 33112 ) on Saturday July 09, 2005 @06:18PM (#13022900)

    The posters here missed the mark.

    Making positrons is actually much easier than making antiprotons. Pair production on photons produced in accelerators should give efficiencies of 5 to 10% -- and the positrons are much easier to cool.

    The big problem with positrons is storing them. Unless these people have a major new idea to get around the Brillouin limit on Penning Traps, the energy stored per mass of equipment will be too small to be interesting (even worse than the energy/mass of chemical propellants.)

  • I was wondering when we would get away from chemical propellant.

    But for any energy medium we don't get out of the ground - we have to harvest/make somehow and that process almost always consumes more energy than what the final product can emit. Is this the case here?

    Not that I care about the energy consumption so much, just the implication to cheap space travel and such, unless we get up off our asses and build fusion reactors.

    But still, the possibilities are endless.

    Geosynched Sattelites may stay up i
  • Pffft, I already have one of these, its crap.

  • The realities of containment (Score:3, Interesting)

    by ChiralSoftware ( 743411 ) <info@chiralsoftware.net> on Saturday July 09, 2005 @07:27PM (#13023243) Homepage
    It seems like they need to produce not just positrons, but full anti-atoms. Positrons all have the same (positive) charge so containing them is hard because they repulse eachother. An anti-atom (ie, positrons oribiting around anti-protons) would be neutral and could even be formed into a solid. This solid could then be suspended. So even if they can generate lots of positrons they still need to generate anti-protons to go with them.

    Also, energy released from antimatter annihilation doesn't come out in a very usable form. From this article [wikipedia.org] it looks like most of the energy comes out as neutrinos. Space is full of neutrinos zipping around, but they're pretty useless for energy because they don't interact with matter to any significant degree.

    It sounds wonderful to have some bit of matter that can be fully converted to energy but I think we'll have commercial fusion power sooner than this can happen.

    Maybe they could figure out how to make smaller, safer fission reactors for these types of missions? Maybe they could focus on fuel efficiency, perhaps even making small breeder reactors for space use?

  • Danger Will Robinson! (Score:3, Funny)

    by FrankieBoy ( 452356 ) on Saturday July 09, 2005 @07:36PM (#13023279)
    Uh-oh: "Positronics Research, headed up by Dr. Smith" Good Heavens! Next it will be "MIT, headed up by Dr. Otto Octavius" or "NASA, headed up by Dr. Victor Von Doom" or "Scientology, headed up by L. Ron Hubbard". Oh the pain...

  • Energy != Propulsion (Score:3, Insightful)

    by klossner ( 733867 ) on Saturday July 09, 2005 @07:57PM (#13023378)
    Okay, so you've got all the energy you can use. You still need to throw something out the nozzle at high speed in order to move -- the rocket equation [wikipedia.org] will not be denied. I'm skeptical about the "10% of conventional propellant" figure, and even more so about scooping propellant out of raw space.

  • Containment, Fah! The OPACITY problem (Score:4, Interesting)

    by StefanJ ( 88986 ) on Saturday July 09, 2005 @08:07PM (#13023411) Homepage Journal
    After years of thinking I knew rocket propulsion -- via SF novels and popular works and, well, building small ones [comcast.net] -- I took a policy course on space travel at CMU. Professor Morel (sp?) insisted that we learn the science first. I got all sorts of good stuff, and started poking around the engineering library for more.

    I found, while researching my term project, a great book on advanced propulsion topics. This wasn't some popular work, but a collection of hard-core equation-filled research papers. There was stuff on what could be the next generation of fission drives, various fusion drive concepts, and antimatter propulsion.

    Beyond the obvious containment issues, there is a BIG problem with antimatter propulsion:

    The problem of opacity.

    Antimatter / matter reactions produce gamma rays. These are extremely energetic and readily penetrate many materials.

    This means that they are very inefficient when it comes to heating up a working fluid. The detail -short linked-to article glibly talks about shooting gamma rays into propellant. They will heat up the hydrogen or water or whatever you are using for a working fluid, but a lot of the energy will simply keep on going, and whiz right through the outside wall of the "combustion" chamber.

    The one research paper which described a "pure" antimatter rocket heated the propellant indirectly. The positrons would be shot into a block of tungsten alloy dense enough to intercept an appreciable amount of the energy produced by the matter / antimatter reaction. Working fluid passed through channels in the block would heat up, turn to gas, and produce thrust.

    The rated Isp was, as I recall, about 5,000 seconds. This is way more than conventional fluid / chemical rockets (500 seconds) and fission rockets (1,000 seconds) but only a little higher than existing ion thrusters (3,100 seconds for that solar-powered testbed that ran a few years back).

    The one advantage this rocket would have over ion thrusters would be the amount of thrust. Ion rockets produce just a trickle of thrust. The antimatter thermal rocket would probably produce a fair amount of thrust, although probably not enough for a ground-to-orbit booster.

    Stefan

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