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Magnetic Ring Could Launch Satellites, Weapons 612

Posted by kdawson
from the round-and-round-it-goes dept.
MattSparkes writes, "A new study funded by the US Air Force has suggested a cheaper method of sending satellites (possibly missile weapons) into orbit. A 2-km-wide ring of superconducting magnets would contain and propel a payload, accelerating it over a period of hours, before suddenly flinging the satellite into space at 23 times the speed of sound. The satellites would be engineered to withstand the g-forces encountered (2,000 g), and be cased in an aerodynamic shell. A two-year study has been commisioned and will begin within a few weeks at LaunchPoint Technologies in Goleta, California." New Scientist points out that if such a launch ring were built, it would instantly become "one of the most important targets on the planet."
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Magnetic Ring Could Launch Satellites, Weapons

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  • by Churla (936633) on Tuesday October 03, 2006 @01:45PM (#16295293)
    Am I the only one seeing the parallel?
    • Re: (Score:2, Informative)

      by kayser_soze (54474)
      No. I thought of the same thing too. Or perhaps the ribbons described in Frederik Pohl's Hechee novels.
      Good stuff. Glad to see someone else who enjoys old-school sci-fi. :-)

      [C]
    • Re: (Score:3, Interesting)

      by pilgrim23 (716938)
      Indeed. also Man who Sold the Moon. Also, if you rememeber 1962: Fireball XL5 http://www.aiai.ed.ac.uk/~bat/GA/fireball-xl5.htm l [ed.ac.uk] -There is a model of the mag lift launcher on that page. The concept has been there for years. Sure it would not work for transporting passengers, but supplies? Chucking O2 cans, rocket fuel, even space food and station building parts into low orbit would become very cost effective.
    • by RM6f9 (825298) *
      I saw it - my question is, if they can't build a straight rail line that'll handle the stresses involved, how will they manage it with a ring??
      • Re: (Score:3, Informative)

        by mrchaotica (681592) *

        Who says they can't? It could just be that a straight-line version would be prohibitively expensive because instead of needing C magnets to span the circumference of the ring, they'd need N * C magnets to span the distance covered by the circumference times the number of revolutions.

    • by gold23 (44621)
      Bingo. They mention in TFA that "[M]ost have focused on straight tracks, which have to gather speed in one quick burst. Supplying the huge spike of energy needed for this method has proven difficult."

      But this quick burst seems to assume that the track is relatively short. Why not a longer track? Which would then obviate the need for payloads or containers that could withstand such high gees (at least the angular ones).

      • by XenoRyet (824514)
        Probably hard to get your hands on a bit of real estate that's the right shape and size for a straight track. At least that's what I imagine the advantage of the ring to be: An arbitrarialy long track within a fixed ammount of physical space.
      • by TubeSteak (669689) on Tuesday October 03, 2006 @02:07PM (#16295653) Journal
        They mention in TFA that "[M]ost have focused on straight tracks, which have to gather speed in one quick burst. Supplying the huge spike of energy needed for this method has proven difficult."

        But this quick burst seems to assume that the track is relatively short. Why not a longer track?
        Take a short track, connect the beginning to the end, and you now have a track of infinite length.

        So they are making a longer track.
        Which would then obviate the need for payloads or containers that could withstand such high gees (at least the angular ones).


        The reason the payload has to be built to withstand X,000 G's is because at some point or another, it is going to go off the track and run into a wall of air at very high speed.
        • Re: (Score:3, Interesting)

          by JonTurner (178845)

          The reason the payload has to be built to withstand X,000 G's is because at some point or another, it is going to go off the track and run into a wall of air at very high speed.

          The shockwave produced by an object moving 23 times the speed of sound suddenly encountering atmosphere would disintigrate it. Unless the track is in a sealed vaccuum, it's going to encounter aerodynamic resistance throughout. And unless this microsatellite acceleates very (VERY!) quickly, the thermal transferrance will turn it int

          • Ablative coating (Score:5, Interesting)

            by maddogsparky (202296) on Tuesday October 03, 2006 @02:34PM (#16296179)
            The reason that most meteors don't hit the ground is because they are so small. The one that do hit the ground and are found right away often have FROST on them since they were so cold in space. As for exploding into a million pieces, meteors aren't designed for reentry.

            Any compentent aeroshell engineer could design a case that would protect the payload (such as a capsule covered with the stuff they use for ablatively cooling rocket nozzles). The big concern usually with burning through airframes isn't that we don't have materials that can withstand the heat and friction; it is that those materials typically aren't very light-weight or are too expensive.

            Besides, once the track is set up, it should be easy to try out new aeroshell designs! One of the stumbling blocks right now is trying to accellerate a test article to high enough speeds. Very often, they stick a test article on a sounding rocket that sends back data during re-entry.

            And yes, IAARS.
          • by doctor_nation (924358) on Tuesday October 03, 2006 @03:29PM (#16297117)
            I was at a presentation last week by the guys in this article.

            The track design is based on particle colliders, so the entire thing is evacuated. Part of it is a rough vacuum and part is a hard vaccum (the actual track). The rough vacuum is because they have to limit thermal transfer to their super-cooled superconducting magnets.

            The acceleration is actually not linear- it's radial. Going around a 2km track at 10km/s has some hefty acceleration associated with it. When ejected into the atmosphere, the projectile shouldn't immediately slow a great deal, although it will lose a lot of momentum before leaving the atmosphere. The design is a very long and skinny cone, to reduce thermal heating and drag force.

            The best thing about this design for a launcher is that it doesn't require a lot of instantaneous power, unlike a linear accelerator. You can accelerate slowly.

            Also, did anyone else immediately think of Xenogears when they saw this?
  • Lost in space (Score:5, Interesting)

    by nizo (81281) * on Tuesday October 03, 2006 @01:46PM (#16295297) Homepage Journal

    If the launch rate reached 3000 launches per year, they calculate that would drop to $189 per kilogram. Today, it costs more than 100 times that to send payloads into space.

    However, Epstein says he cannot imagine a demand for that many launches in the foreseeable future.


    Space burials (presumably of cremated remains). At $200 each (plus cremation) I am sure they could sell a few thousand of these per year. Now if they could only figure out a way to allow living people to withstand 2000g of acceleration, space tourism might actually be affordable.

    • by TopShelf (92521)
      Better yet, combine both your ideas into one. All aboard the Carousel [imdb.com]!
    • Nuclear waste?
    • Re:Lost in space (Score:5, Insightful)

      by Alef (605149) on Tuesday October 03, 2006 @02:38PM (#16296269)
      At $200 each (plus cremation) I am sure they could sell a few thousand of these per year.

      Well, a few thousand cremated bodies would probably fit inside one single launch, so you would need millions to get that price. Because I seriously doubt the $189/kg figure assumes 1 kg payload/launch.

  • by ackthpt (218170) * on Tuesday October 03, 2006 @01:48PM (#16295317) Homepage Journal

    that gauss density could be fatal and/or affect instruments.

    I know there's a relationship between bird migration and magnetic fields, too, as a lot of them blindly smack into the brick walls at a local MRI center.

    • by jbeaupre (752124)
      I'm thining it's a coincidence. Birds do use magnetism for navigation. But they don't just blindly follow field lines. Otherwise they'd be smacking into mountains, trees, buildings, etc. during migrations with or without MRI's around. Also, MRI's are heavily sheilded.
    • by NoData (9132) <_NoData_@@@yahoo...com> on Tuesday October 03, 2006 @03:02PM (#16296715)
      I know there's a relationship between bird migration and magnetic fields, too, as a lot of them blindly smack into the brick walls at a local MRI center.


      Cute, but you gotta be kidding. I work with a 3T research MRI magnetic. Both the machine and the facility are heavily shielded, and the field drop-off is very steep. While the isocenter of the bore is at 3 Tesla (30,000 Gauss), the 5 Gauss line is only a few meters (about 5 in the axial direction, 3 in the radial direction) from the isocenter. By comparison, a kitchen magnet is maybe 100-250 Gauss.
  • by patrixmyth (167599) on Tuesday October 03, 2006 @01:49PM (#16295337)
    We could fling refrigerators at North Korea! How's that missile testing going, Kim, did we mention we can launch frigidaire's into orbit? I'd prefer launching cows in homage to Monty Python and the Holy Grail, but at 2000g, that would probably equate to throwing hamburger.
    • Re: (Score:3, Interesting)

      by LWATCDR (28044)
      Not all that funny. Make a payload of tungsten and some type of guidance system and you have a fractional orbital bombardment system. A 1000lb slug of tungsten hitting a target at 18,000 mph would make a nice sized hole.
  • by Quiet_Desperation (858215) on Tuesday October 03, 2006 @01:49PM (#16295345)

    Yes!

    As for it being a target, fuck that. Full steam ahead.

    If we're not driving payloads into space at Mach 23 within 10 years, the terrorists have already won. Or something.

  • "New Scientist points out that if such a launch ring were built, it would instantly become "one of the most important targets on the planet.""

    I knew lawn darts were dangerous...but god-damn.
  • The claim is that the ring could put payloads into orbit for $745 per kilogram.

    What's the bet that, like most estimates of this kind, it ignores the cost of building the ring to start with...
  • If this ring is going to be "one of the most important targets on the planet", maybe they should build it as a series of concentric rings instead of a single ring. Perhaps havethe rings use alternating colors.
  • This would seem to be an obstacle for launching things like communications satellites, but Fiske points out that the US military uses electronics in laser-guided artillery, which survive being fired out of guns at up to 20,000g.

    I wasn't aware of laser-guided artillery.

    I know of laser-guided rockets and missiles and such. But I was under the impression that anything lauched from a cannon depended upon the artillery team to have done the calculations prior to firing it.

    • A quick Google search turns up several pages of results; I'll let you decide waht is useful.

      Yes, it depends on the calculations prior to firing it. But those calculations can be based on a laser targeting system, and minor course corrections can be done in mid-flight by airfoils.
    • Here: (Score:5, Informative)

      by jbeaupre (752124) on Tuesday October 03, 2006 @02:04PM (#16295601)
      http://en.wikipedia.org/wiki/M712_Copperhead [wikipedia.org]

      Now you're aware...
    • by Gruneun (261463)
      As far as the US military goes, there are plenty of machines that fire rockets, but are considered artillery units. The term is a catch-all that covers far more than cannons or their projectiles.
    • Re: (Score:3, Informative)

      by multiplexo (27356)
      We've had laser guided artillery rounds since the 1970's. The 155mm Copperhead rounds have a target sensor and you had an forward observer with a laser designator to light up the targets. Some calculation is necessary, you have to make the calculations to get the round close to the target, but once you've done that the FO can illuminate the target and the round will home in on it, making it possible to use artillery to take out tanks.

      The laser designator for the Copperheads was quite large, the ones I saw

  • by good soldier svejk (571730) on Tuesday October 03, 2006 @01:52PM (#16295403)
    That sounds like a big Gauss Gun, AKA rail gun to me. The Germans tried to build long range artillery and anti-aircraft artillery on on this principle during WWII. Makes sense I suppose, as Carl Gauss was German. Of course, it was quickly superceded by their deadly LePage Glue Gun Technology.

    "Yossarian sidled up drunkenly to Colonel Korn at the officers' club one night to kid with him about the new Lepage gun that the Germans had moved in.

    What Lepage gun?" Colonel Korn inquired with curiosity.

    "The new three-hundred-and-forty-four-millimeter Lepage glue gun," Yossarian answered. "It glues a whole formation of planes together in mid-air."

    - Catch-22, Joseph Heller
    "
    • Not a rail gun. (Score:5, Informative)

      by MoralHazard (447833) on Tuesday October 03, 2006 @02:13PM (#16295757)
      Your lapse is forgivable, but only because the proliferation of terms like "Gauss gun", "rail gun", and "mass driver" in SF has overwhelmed their usage as technical terminology. But the point is, THIS IS NOT A RAIL GUN.

      A rail gun is a parallel, non-touching pair of conductive rails, joined at the back-end by a partial circuit capable of generating an extremely high current flow (amps) of electicity in a very, very short time. A conductive projectile is injected into the gap between the rails (so that it touches both rails at once), which completes the circuit. As current flows from one rail to the other, through the projectile, it generates a powerful magnetic field. The Lorentz force causes the projectile to be pushed toward the far end of the rails--the magnitude of the force depends on the current flow.

      Rail guns can achieve extremely high velocities, far higher than conventional explosive-charge guns. The velocity of a firearm projectile is limited by the velocity of the expanding explosive gasses that propel it out of the barrel; the gas velocity is in turn limited by the speed of sound in the gas medium, which has a physical upper limit for any type of explosive. Rail guns don't suffer from this limitation.

      I have seen references to a 'Gauss gun' which consists of a series of solenoids stationed along a tube barrel, timed to trigger so that a ferrous metal projectile will be pulled faster and faster down the barrel by each of the solenoids in turn. I don't know how valid this terminology is, though.
  • by dave-tx (684169) * <df19808+slashdot AT gmail DOT com> on Tuesday October 03, 2006 @01:55PM (#16295447)

    Suggestion for the first test: Enter it in next year's Punkin Chunkin' [punkinchunkin.com] contest!

  • This is a decades old concept.

    Direct launch using the electric rail gun [harvard.edu]
    In APL The 1983 JANNAF Propulsion Meeting

    A better implementation than the artist's conception that I've previously heard of, was to build the rail gun into a tall mountain.

    The primary reason was to help get above the bulk of the atmosphere, but it also has the added benefit of being extremely secure.
  • by m0llusk (789903) on Tuesday October 03, 2006 @01:57PM (#16295481) Journal
    One ring to launch them all,
    one ring to fling them.
    One ring to send them into space,
    and into that darkness bring them.
  • for 2 hours,

    19620 m/s^2 * 7200 seconds = 141264000 m/sec

    Somehow I don't think that this is right.
    • Re: (Score:3, Insightful)

      by mrchaotica (681592) *

      You forget that it's circular. It's accelerating by changing direction as well as increasing speed.

  • A few points (Score:5, Insightful)

    by argStyopa (232550) on Tuesday October 03, 2006 @02:04PM (#16295603) Journal
    First the FUD:
    New Scientist points out that if such a launch ring were built, it would instantly become "one of the most important targets on the planet.
    What a moronic comment.

    You have a STATIC launcher.
    It can toss things into ballistic trajectories.
    One at a time.
    With a warm-up of TENS OF HOURS.

    I don't know if New Scientist realized this, but we have launch technologies that are
    a) less vulnerable
    b) more accurate
    c) mobile
    and
    d) a little quicker to fire than that.

    On another note, and not that this will mollify the crowd that fears a weapon in every technology, but in regards to the difficulty of punching something through the atmosphere at Mach 23, I seem to recall SDI experiments where a high-power laser was used to heat a 'track' through the atmosphere (in that case, to fire a particle beam weapon down the track with less atmospheric attenuation ). Couldn't a similar idea significantly reduce the air resistance for this sort of a projectile?
  • Are you guys paying attention? I see a new ride in the next few years ahead!
  • hmmmm.. perhaps if we build it on the surface they will come...
  • by Optical Voodoo Man (611836) on Tuesday October 03, 2006 @02:14PM (#16295765)
    I found it interesting that the article stated:

    "When the sled had been accelerated to its top speed of 10 kilometres per second, laser and pyrotechnic devices would be used to separate the cone from the sled. Then, the cone would skid into a side tunnel, losing some speed due to friction with the tunnel's walls. The tunnel would direct the cone to a ramp angled at 30 to the horizon, where the cone would launch towards space at about 8 kilometres per second, or more than 23 times the speed of sound. ... Anything launched in this way would have to be able to survive enormous accelerations - more than 2000 times the acceleration due to gravity (2000g)."

    They claim that the payload would be accelerated slowly around the ring. The huge acceleration occurs when the payload's trajectory is changed to angle it up 30 degrees towards the sky. Why wouldn't they angle the ring itself at 30 degrees, releasing the payload at the point where the tangent points up at 30 degrees? They wouldn't need a ramp at all, just a piece that moves out of the way before the payload swings around the loop again.

    • by truthsearch (249536) on Tuesday October 03, 2006 @02:58PM (#16296655) Homepage Journal
      A few reasons... the ring is kilometers long. Angling it at 30 degrees would force you to build it deep into the ground, high into the air, or both. But more importantly you'd only have one launch trajectory. By having one ring and a mobile launch tunnel you have 360 degrees to choose from (ideally). The ability to change launch direction is probably more important than the complications it adds to the launch physics.
  • by PHAEDRU5 (213667) <instascreed.gmail@com> on Tuesday October 03, 2006 @02:17PM (#16295849) Homepage
    You mean, like Vandenberg, and Cape Kennedy, and...

    Anywhere the capability exists to put a payload into orbit is a target.

    That "most important target" bit was a simple piece of scaremongering.
  • Gerald Bull (Score:4, Insightful)

    by freelunch (258011) on Tuesday October 03, 2006 @02:23PM (#16295953)
    The article and basic approach remind me of Gerald Bull's work [std.com] and his disturbing tale of doom as documented on the Doomed Engineers site [std.com]:

    Gerald Bull had a vision and an obsession, a vision that led to estrangement from his native Canada, prison in America, and ultimately assassination by Israel. His vision was of an entirely new way to get into space: small rockets boosted by giant guns. To achieve it he worked for some of the worst regimes on earth: South Africa, China, and ultimately Iraq. His work affected the course of two modern wars and revived the ancient field of artillery.
  • by LotsOfPhil (982823) on Tuesday October 03, 2006 @02:31PM (#16296125)
    What about using this thing to shoot water/food/structural materials into space? That is where the savings really come into play. If there is to be a moon base, all the water has to be shipped up there. People need lots of water, so cutting the cost per kilogram to 1% of current levels is a very big deal.
  • by TigerNut (718742) on Tuesday October 03, 2006 @02:39PM (#16296295) Homepage Journal
    TFA mentions they're going to accelerate it in a circle, to about 10 km/s, and then divert the launch projectile onto a ramp which will deflect it upward at a 30 degree angle, at about 8 km/s. There's a huge amount of energy dumped into the ramp there... why not build the accelerator at a 30 degree inclination to the horizontal, and then all you have to do is let it go at the appropriate time, and you won't be losing 20% of your speed due to the friction of the ramp.
  • Bad math? (Score:5, Informative)

    by Bender0x7D1 (536254) on Tuesday October 03, 2006 @02:44PM (#16296391)
    Am I crazy, or did they get the math wrong in the article?

    The acceleration equation for circular motion is: a = v^2 / r

    We are given:

    Velocity: 10 kilometers/s

    Width of ring = 2 kilometers, so radius = 1 kilometer

    So:
    v = 10,000 m/s
    r = 1,000 m

    a = (10,000 m/s * 10,000 m/s) / (1,000 meters) = 100,000 m/s^2

    The acceleration due to gravity is about 10 m/s^2

    This gives: (100,000 m/s^2) / (10 m/s^2) = 10,000 g

    So it seems that their 2,000 g is way off. Even if we use 2 km for the radius it is still 5,000 g.
    • Re:Bad math? (Score:5, Informative)

      by doctor_nation (924358) on Tuesday October 03, 2006 @03:38PM (#16297215)
      Your math is correct. I have an abstract from a presentation these guys gave last week and it lists the radial force at 20 MN (that's mega-Newtons) for a 200 kg projectile = 10,000 G. They don't list the acceleration in G anywhere so it's probably a New Scientist math error.
  • Fuel and Water (Score:5, Interesting)

    by WindBourne (631190) on Tuesday October 03, 2006 @03:00PM (#16296671) Journal
    The long-term expensive part about space is not sending equipment up. It is the costs of fuel, water, air, and food i.e. consumables. Fuel and Water can all withstand the high Gs. If this works, the first thing that would make sense is to send all of these up. At that point, you can make the ring pay for a large part of its costs. From there, sats. can be developed that can withstand those forces.

    The down fall is that the privatization world will probably be a bit upset about this.
    • The down fall is that the privatization world will probably be a bit upset about this.

      The current crop of privateers, yes. If a space-oriented VC could envisage a suitable marketing plan, this would be the ideal private space infrastructure project. Most of the existing cheaper-faster-better startups focus merely on making a cheaper tube 'o fuel. Our current crop of missile makers are still basically building their product by hand. When a launch vehicle and payload go BOOM, a good portion of the contractor'
  • Why electronics? (Score:3, Insightful)

    by cfulmer (3166) on Tuesday October 03, 2006 @03:04PM (#16296749) Homepage Journal
    Geez... There are all sorts of things that you might want to fling into space where you don't really care that much about being gentle. For example, use it to fling food and water up to the space station.
  • by Big_Breaker (190457) on Tuesday October 03, 2006 @03:15PM (#16296937)
    This ring could fling mass up to a skyhook to recharge its orbit. Imagine a LEO skyhook that catches dozens of dead weight shots from this gun and uses that momentum to promote its orbit to a highly eccentric one. Then the satellite can exchange this orbit potential with a target at its low altitude point through a tether or skyhook style method. The target could be a large satellite in LEO or even a suborbital payload. Once the potential is transfered the target can have its orbit promoted to GEO or other significant altitude.

    This method saves a lot of reaction mass in a heavy lifter because you can aim for a high alitutde but a suborbital trajectory. IE it's easier to shoot straight up than curve towards an orbital path at sufficient speed. For instance the X prize is all about sub-orbital. LEO is much harder and GEO is even harder still.
  • by AJWM (19027) on Tuesday October 03, 2006 @04:29PM (#16297911) Homepage
    A 2-km-wide ring of superconducting magnets would contain and propel a payload, accelerating it over a period of hours,

    So it's wasting all that energy making it go around in circles (it's changing direction, thus accelerating) while it ever-so-slowly ("a period of hours"!? ye gods and little fishes!) to escape velocity. I got news for you -- a low acceeration rocket like the Shuttle makes orbital velocity in 8 minutes at a modest 3 Gs.

    Orbital velocity is about 7km/sec. Say 10km/sec to allow for drag losses escaping the atmosphere and gaining altitude. Accelerate at 1000 G and you can reach that speed in 1 second, in a distance of 5 km.

    They're talking about a ring 2 km wide; take that as the diameter and they're talking a 6.28 km circumference. With fewer magnets and less total energy they could do it with a linear accelerator.

    What idiot wasted taxpayer dollars thinking this up?

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