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Space Science

Modular Laser Launch Systems 152

Posted by michael from the future's-so-bright-you-gotta-wear-shades dept.
BerntB writes "I don't think Jordin Kare's NIAC article has been covered? It's about using new laser tech to build modular laser launch systems. The modular nature makes it easier to test and build. The only other launch ideas as cool are the Orion Project and the space elevator."
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Modular Laser Launch Systems More

Modular Laser Launch Systems

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  • This is the only orbital platform technology... (Score:5, Funny)

    by Anonymous Coward on Saturday July 10, 2004 @09:19PM (#9663717)
    ...that offers a built-in light show and 1600x DVD burning.

  • Slashdot Meter (Score:4, Funny)

    by soloport ( 312487 ) on Saturday July 10, 2004 @09:25PM (#9663747) Homepage
    Just so cool to watch the meter go from "000350 Number of Hits Since Mar 10, 2000" to "000501" in a mater of seconds (by hitting reload). Mesmerizing!

    I miss seeing more hit meters around the web.

  • Yeah but... (Score:5, Funny)

    by pyrrhonist ( 701154 ) on Saturday July 10, 2004 @09:26PM (#9663751)
    Can it launch other things besides lasers?

    Oh. Nevermind...

  • has gotten more visits in 5 minutes then it has in 4 years...
  • Oh, well, at least it's less likely to get slashdotted this way.

    Anyway, more ontopic; this doesn't seem like that new an approach. Modularisation of space items has always been around. It allows you to concentrate on getting each item working at 100% instead of having to rely on one monolithic structure. Modularising laser launch control systems has just not been done in the past because it was hitherto too inconvenient.
    • Nope. 709k Final report pdf there too.
    • There's also a .pdf that you can download.
    • Ok, this is a crazy idea, so you might want to make fun of me.

      1. Push a really long cylindar (full of air, or much lighter than water) strait down into the ocean.

      2. Put something on top, to go to space.

      3. Let the cylindar go.
      • Even better:

        1. Push really long cylinder down, letting it fill with water so you have an easier time controlling it on the way down, and you don't have to use as much force.
        2. Push air/(liquid helium easier for transportation down?) down into it when it's firmly locked in place by some mechanism. If you used helium, let it expand inside your super-rigid cylinder.
        3. Now release it with the payload on top. Better do this in some place where the currents are neglible compared to your force on the way up,

  • Jerry Pournelle (Score:5, Informative)

    by multiplexo ( 27356 ) on Saturday July 10, 2004 @09:33PM (#9663774) Journal
    used to write about these in his stories in the 1970s and also wrote about them in his book A Step Farther Out. You can probably go to his website, http://www.jerrypournelle.com, browse around and find more information, or send Dr. Pournelle an e-mail.

    • Also featured in Footfall [wikipedia.org].
    • I just finished re-reading Niven and Pournelle's Footfall, which is a pretty well-told story of humanity's war with peculiar invaders. In it, they employ laser jet launching (ground-based laser vaporizes interior of jet bell to produce jet thrust), Orion propulsion (series of atomic explosions under hemispherical blast plate), and the Bussard ramjet (ramjet which collects and ejects interstellar hydrogen).

      I love re-reading older science fiction just to see how badly they foretold their futures. Most st

    • Re:Jerry Pournelle (Score:3, Informative)

      by calidoscope ( 312571 )
      I was thinking the same thing when reading the intro - remember reading one of the stories in Digital -er- Analog SFM (ca 1974).

      A few years ago, Scientific Amrican published a piece on possible space propulsion methods. One was using lasers and a "solar sail" credited to Robert Forward. I wrote the editor saying that Niven and Pournelle came up with the idea in the early 70's - Niven used it in a short story - and it was used in "The Mote in God's Eye" (noted that someone else made reference to escaping th

      • Re:Jerry Pournelle (Score:3, Insightful)

        by putaro ( 235078 )
        Well, unsubscribing to Scientific American was the right thing to do but Forward is generally credited as the first person to tie lasers and solar sails together One source that I have ("The Starflight Handbook") credits him with talking about these shortly after the invention of the laser in 1960. As you mentioned, Niven, Pournelle and Forward were friends and Niven credits a number of ideas he used in fiction to Forward.

        A large amount of Niven's fiction starts with some scientific theory or fact that h
  • The only other launch ideas as cool are the Orion Project and the space elevator.

    You forgot Project Promethius.
    • Project Promethius

      Promethius is not a launch solution. It's a nuclear powered Ion Drive. Energia Vulkan, Sea Dragon, and the Gas Core Nuclear "Liberty Ship" are all cool launch solutions he forgot.

      • Energia Vulkan, Sea Dragon, and the Gas Core Nuclear "Liberty Ship" are all cool launch solutions he forgot.
        I wrote "as cool as" Orion and an elevator! :-)

        "Sea Dragon" was chemical (yawn) and Energia Vulkan too, right? But, sure, they were big!

        (They really planned to launch using a gas core??)

        • "Sea Dragon" was chemical (yawn) and Energia Vulkan too, right?

          Nothing wrong with chemical. As a planetary heavy launch solution, it actually isn't bad. In fact, Sea Dragon would be downright cheap. It's just that no one really *wants* to launch huge payloads. That's why we stopped manufacturing the Saturn V.

          As for space-based propulsion, I would absolutely LOVE to see Zubrin's Nuclear Salt Water Rocket pan out. Speaking with nuclear engineers, they either believe it would take some serious R&D to ma

  • Went to a lecture on this by Jordin a while back (Score:5, Informative)

    by WolfWithoutAClause ( 162946 ) on Saturday July 10, 2004 @09:45PM (#9663809) Homepage
    There's a few 'gotchas':

    a) the vehicle may blind by reflected light at a considerable distance (100m - 1km or more- think of the wildlife [handwring]).

    b) it ideally uses pure liquid hydrogen fuel; this means that the fuel tank ends up pretty heavy relative to the fuel (heavier than the space shuttle, because the Space Shuttle tank also holds LOX, so the average propellent density is rather better.) The ratio of the vehicle weight full/empty is critical in a high performing rocket- so this rocket doesn't perform as well as you would hope- it's not a SSTO solution, not quite, so he has a drop tank or two.

    c) got a few billion? The lasers are very expensive... note that conventional rockets can be designed for *well* under a billion if you don't do anything fancy (see SpaceX [spacex.com])

    d) it works best when you are launching a lot, but then again, just about any launch system gets cheap real fast if you launch a lot; and this one is expensive up front, so you have to launch even more to offset this.

    Still, it's a very cool idea, and he's still working on it. But I can't shake the feeling Jordin has missed something that will move the idea up one more notch.

    • Re:Went to a lecture on this by Jordin a while bac (Score:1, Interesting)

      by Anonymous Coward
      In this Phase I effort, we will analyze the performance requirements and scaling of modular laser launchers using various current and proposed laser technologies, develop baseline designs for possible beam modules, and define a roadmap for technology development and deployment of a modular laser launch system.

      they are just doing a requirements analysis, they are deciding if its feasable, so he's not missing anything.

    • You are wrong.

      LH tank weight is exactly the same problem with both shuttle and this approach (using LH as monopropellant + laser heating).

      The main limitation of rocket propulsion is the weight of the oxidizer. Even with LOX (most weight-efficient oxidizer) the weight of the oxygen is 8x higher than the weight of hydrogen. And you need lotsa fuel/oxidizer to lift the weight of the fuel/oxidizer, etc. Any weight savings will greatly reduce the overal rocket mass and size.

      Compared to shuttle (without SRBs)
    • Those gotchas don't seem to be much of an issue:

      a) The vehicle could be dropped from several km up in the air where no wildlife would be endangered (like the recent launch of SpaceShip One)
      b) Being able to launch with reduced/no oxidizer would be a HUGE weight savings, significantly decreasing launch cost (as a sibling post noted). There are actually two tanks within the external fuel tank of the shuttle, a huge one storing LOX and a much smaller one storing the H2.
      c) The lasers would be completely reusa

  • How Ironic... (Score:5, Interesting)

    by Baldrson ( 78598 ) on Saturday July 10, 2004 @09:49PM (#9663814) Homepage Journal
    The only other launch ideas as cool are the Orion Project and the space elevator.

    Since the prior story is about Carnegie Mellon [slashdot.org] its rather ironic that the most intriguing launch technology was left off entirely -- and it is out of the robotics department of CM: the Rotovar(tm) by Hans Moravec [cmu.edu].

    We investigate a cheaper system. A satellite in low circular equatorial orbit has two long cables extending in opposite directions. It rotates in the orbital plane, and the cables touch the planet each rotation, with the rotational velocity canceling the orbital velocity. The system acts like two spokes of a giant wheel rolling on the equator.

    The orbit is stable, and the taper is minimized when the satellite's diameter is one third the planet's. On Earth it is 4000 km long and touches down every 20 minutes, every 2 hours at six points. Cable motion near the ground is vertical and uniformly accelerated at 1.4 g. The maximum velocity in the atmosphere is 2 km/sec. One eighth the strength of graphite gives it a taper of 10:1, and it can lift 1/54 of its own mass at each contact.

    The central idea in this paper, of a satellite that rolls like a wheel, was originated and suggested to me by John McCarthy of Stanford [stanford.edu]. He also encouraged the work and provided many of the resources for it. The symbolic mathematics was done with the MACSYMA system being developed at MIT. This program behaves like a programmable desk calculator that deals with algebraic expressions instead of simply numbers. It is capable of solving equations, integrating formulas, taking limits and much more.

    • the

      most intriguing launch technology was left off entirely

      Well, I'll agree. That is cool (I check Moravec's home page every few months) -- but "just" a skyhook variant of the true elevator. :-)

      I'll agree that it's a neater and probably more cost effective solution (given the right conditions) -- but hardly as cool as the real elevator going to orbit from the ground...

      I should have added a link to the whole site [usra.edu].

      • Think time value of money.

        How much of a loan do you have to take out to pay for an elevator? How much of a loan do you have to take out to pay for a Rotovar(tm)?

        Now, what's the mass flow rate to orbit of the elevator? What's the mass flow rate of the Rotovar?

        I think if you do the calculations you'll find there's really no comparison -- the Rotovar wins hands-down.

        • Think time value of money.
          No, I don't. The specific point was coolness. Return on investment is, of course, more relevant if a system will be built.

          (Besides, as I remember -- the Rotovar need an infrastructure in space so you have payloads to send down, too?)

          • Well "coolness" is pretty subjective, but I'll go along with your assessment of the space elevator -- it just seems really "cool". Unfortunately, that may be one of its drawbacks if it is indeed not an equally viable approach to getting off this rock. People thought the Space Shuttle was "cool" too.

            The Rotovar, in its optimal implementation, has a number of momentum exchange stages between the Earth and the Moon, moving lunar material to the Earth as terrestrial material goes to the Moon. This is very

            • Well, if someone calls something cool, I think you can assume an "IMHO" on it... :-)

              The elevator needs infrastructure on Earth, not on Moon.

              Chicken/Egg problem. (Been/stalk problem, rather?)

              How do you afford to get that infrastructure up without breaking the country's budget?

    • You had me until you started talking about magnetic monopoles. Crackpot alert!
      • Magnetic monopoles were hardly considered crackpot in 1977, and Hans Moravec [cmu.edu] is hardly considered a crackpot in engineering. It is always dangerous to try to predict future advances in engineering based on present speculative theory -- as was necessary when trying to derive the "unobtanium" required for various proposed structures such as the Rotovar(tm). He did at least spend the lions share of his speculation on graphite "whiskers" which is related to carbon nanotubes.
    • Hrm. I read about it first in "Indistinguishable from magic" by forward. 'course, he could have heard about it from McCarthy: I don't recall.

  • Look at the numbers on this (Score:5, Informative)

    by Animats ( 122034 ) on Saturday July 10, 2004 @09:58PM (#9663839) Homepage
    Laser launch is a nice idea, but the power requirements are huge. The current altitude record is 71 meters [space.com] (not kilometers), with a 51 gram (not Kg) craft and a 10 kilowatt laser.

    Kare, who's been plugging this idea for decades, writes "A rule of thumb for laser launchers is that the unit payload is 1 kg per MW of laser power." The Apollo lunar module (all the stuff that went to the moon) massed about 6500 Kg, of which 2500Kg made the round trip. So we're going to need several gigawatts of laser power for a moon shot.

    Kare is talking about using continuous diode lasers in the 1KW range. These don't exist, but 60W units are available, so this isn't totally unreasonable. Kare proposes to use maybe 150 of these future 1KW units in a prototype. That only launches a 150g craft.

    Launching something the size of the Apollo lunar module would take six million such units, and about 12 gigawatts of electrical power for several minutes. This is twice the power output of Grand Coulee Dam, the biggest single power source in the US.

    The power storage problem might be overcome using ultracapacitors. You can get 2600 farad capacitors (not ufd, farads) at 2.5V today, and you can take current out fast. Auto engines can be started with six of these things, weighing a total of about 3Kg. With a big budget, a laser launch system could have enough energy storage to do the job.

    Six million lasers, though, is a bit much. The prototype doesn't put enough mass in orbit to be useful, and the real version is too big.

    If you want to launch a microsat, you call Orbital Sciences Corporation [orbital.com], and they launch a Pegasus rocket from a L-1011 for you. The X-prize guys get all the press, but Orbital actually puts stuff in orbit. They've launched 45 payloads so far. Click here [orbital.com] for their user manual.

    • You mean Jiggawatts, don't you? Actually, supercaps are probably not up to the job, but a Flux Capacitor ... now we're talkin'.
    • Launching something the size of the Apollo lunar module would take six million such units, and about 12 gigawatts of electrical power for several minutes.

      12 gigawatts!? 12 gigawatts!? Great Scott! Where are we going to come up with that kind of power? We'd need to harness a lightning bolt as it strikes the Clock Tower or something!
      • Ten lightning bolts, actually.

        1.21 Gigawatts was what the Flux Capacataor needed. So, to launch an Apollo lunar module, you'd need to hardness ten good-strength lightning bolts at a more or less constant rate.

        Even if you had perfect efficiency, I don't think there are 10 constant lightning bolts in the entire country. (Say 1 second for a lightning bolt, and 5 minutes to launch... 3,000 lighning strikes. Not even sure that much hits the whole country in a year.)
        • Wikipedia gives your average lightning bolt a current of 30kA and voltage of 100MV, over just few milliseconds, which equals to staggering 3 000 000 000 000 Watts (three thousand gigawatts), others quote 10 billion joules which over same 2ms period would be slightly more (5E12 W) so looks like Flux Capacitor was quite badly overdosed.

          Even if you had perfect efficiency, I don't think there are 10 constant lightning bolts in the entire country. (Say 1 second for a lightning bolt, and 5 minutes to launch...

    • Re:Look at the numbers on this (Score:5, Informative)

      by pyrrhonist ( 701154 ) on Saturday July 10, 2004 @10:32PM (#9663946)
      The power storage problem might be overcome using ultracapacitors. You can get 2600 farad capacitors (not ufd, farads) at 2.5V today, and you can take current out fast. Auto engines can be started with six of these things, weighing a total of about 3Kg. With a big budget, a laser launch system could have enough energy storage to do the job.

      Actually, there's an easier way. I had a chance to tour the Princeton Plasma Physics Lab when they were still doing experiments with their big tokamak.

      One of the things about doing plasma physics (i.e. attempting neclear fusion) is that you need an absolutely ginormous amount of energy to get the experiment started. What's more is that pulling all this energy off of the power grid at once and then dropping the load causes some, shall we say, "slight instabilites", with the power grid.

      So, the way you get enough power is to slowly bleed power off of the grid and store it somewhere so that you can use it all at once at a later time. The way that they did this at the PPPL is with huge concrete discs encased in concrete bunkers that gradually spun up as more energy was applied. When enough energy was stored kinetically, they'd disconnect from the grid and apply the brakes to the discs to generate electricity for the experiment. At least this way, NJ was never blacked out, because of an experiment.

      The amount of energy these things can store is amazing. One time, one of the discs broke. Most of the pieces embedded themselves in the bunkers, but one piece bounced around and flew out. The piece landed 40 miles away.

      • Yeah, right.
        • Do you have any idea how much rotational energy they store into one of those? You're talking about a concrete disc spinning at something like 50-100,000 RPM. Stored rotational energy goes up as the square of the speed of rotation, so you can have a LOT of energy in a chunk of concrete.

          Let's do the math. You take a 1 ft diameter 50 lb flywheel spinning at 100,000 RPM - these do exist (read up on Jack Bitterly). That's KE = 1/2 I omega^2, which for a circular disk of uniform density works out to:

          I = 1/2
      • The story is very interesting, but they did not apply "brakes": they simply turned the motor into a generator. Depending on the current (and therefore energy output) of the generator, an induced magnetic field is formed within the generator, which acts in the direction opposite to the rotation. The higher the current, the stronger this field is, and the quicker the rotor decelerates.

    • The power storage problem might be overcome using ultracapacitors. You can get 2600 farad capacitors (not ufd, farads) at 2.5V today,...

      Capacitor energy density is pathetic: cost and energy both scale as physical size.

      Superconductive coils are better: Cost scales a little less than radius, but energy scales as radius squared. On the other hand there may be problems getting the energy out fast enough. (Problems like radially pumping ground water that rips open the coil container.)

      Another possibility

      • SMES (Superconducting Magnetic Energy Storage) probably does have an advantage over ultracaps for the moment, but there are enough interesting applications for ultracaps that they will soon pull ahead of SMES.
    • You missed one quite obvious point:
      If we could launch 100-200 kg packages for a few hundred dollars/kg (instead of hundred times as much/kg), we could do lots of stuff we can't do today.

      Payloads heavier than that (which can't be split into small parts) will be launched some other way.

      (And, yes, the Pegasus exists today. How much did it cost/kg? How many universities can afford to send some instruments somewhere?)

    • ...12 gigawatts of electrical power for several minutes...

      You can get 2600 farad capacitors (not ufd, farads) at 2.5V today, and you can take current out fast. Auto engines can be started with six of these things, weighing a total of about 3Kg.

      Okay, call it 1000 F at 2.5 V, per kilogram. That's about 3000 J. Assuming that we need to deliver that over a three minute period, we're looking at (round figures) 20 W.

      To deliver 12 GW for three minutes, that's 600 million kilograms--600 thousand tons--of c

      • That calculation is off by a factor of 5, but the numbers are still huge.

        First, let's look at the Maxwell BCAP0010 Ultracapacitor [maxwell.com]. 2600F, 2.5V, 525g, 60mm diameter cylinder, 172mm length. Incidentally, of these can deliver 600A for 5 seconds, if you need that much power all at once. These aren't like those high-resistance supercapacitors used to keep computer clocks alive with a trickle. Ultracapacitors can deliver serious current. Six of these can start an auto engine.

        This is about 5000 farads per

  • Beam me up scotty! (Score:3, Insightful)

    by stock ( 129999 ) <stock@stokkie.net> on Saturday July 10, 2004 @10:08PM (#9663870) Homepage
    Do i understand this correctly? Nasa wants to use a high-power ground-based laser as the heating supply for the power needed to ignite the H2 fuel in the Primary Propellant Tank? And as such they gonna aim their laser over very large distances to a so-called Leighweight Heat Exchanger as a shooting target ? (see figure 1 on page 6).

    There's some rather severe pitfalls to be considered with this method :

    1. if the spacecraft abusively rotates around its length axis, the power from the ground laser might not be able to reach/hit that Heat Exchanger target any anymore, hence the rockets drops its speed instantly, leading to even more fatal flight manouvring.

    2. As the rocket is approaching large heights, the laser guiding system will be put to the real test. When the "lock-in" signal is lost, you loose everything.

    3. The conventional iginition system should allways be present as a backup system. In that case the net effect is just that extra costs are introduced.

    I personally see this project more as a nice step-up for developing and deploying guided high-power ground-based lasersystems, which can follow ("lock-in") their target to very large heights. a laser "lock-in" in the end might even be possible on rockets (targets) which are near the moon. Doesn't that closely resemble the "StarWars" program of former president Ronnie Reagan ?

    Robert

    • no ignition at all (Score:3, Interesting)

      by r00t ( 33219 )
      This rocket skips the oxygen, which is heavy.
      There is only hydrogen being boiled off by the laser.

      Hydrogen is only 2 protons per molecule,
      the same as helium, without the neutrons.
      (plus some insignificant electrons, minus some
      bits from e=mc^2, and so on)

      At low altitude of course, all that hydrogen
      will burn when it hits the air outside the rocket.
      Oh well. So the exhaust catches on fire.
      • Hydrogen only has 1 proton... that's why it has an atomic number of 1 and has one electron. If it had more than one proton it wouldn't be hydrogen anymore.

        Someone slept through chemistry class... (Shame too, 'cause the rest of the post is correct and the part that was wrong didn't need to be there at all)
        =Smidge=

        • Re:no ignition at all (Score:3, Informative)

          by scheme ( 19778 )

          Hydrogen only has 1 proton... that's why it has an atomic number of 1 and has one electron. If it had more than one proton it wouldn't be hydrogen anymore.

          Someone slept through chemistry class... (Shame too, 'cause the rest of the post is correct and the part that was wrong didn't need to be there at all)

          The original post said hydrogen with 2 protons per molecule which is true since hydrogen is normally found as H2 with two atoms bonding to form a diatomic molecule.

          Someone didn't read the original post

        • As someone else reminded you, hydrogen molecules
          contain two atoms.

          The weight per molecule matters. For rockets
          and explosives, you get a better device if the
          exhaust gases are composed of lightweight
          particles. Hydrogen satisfies this better
          than any other stable molecule.
    • There's some rather severe pitfalls
      Assume a ten percent loss ratio. It's still a cheap way to send up easily replaceable material.

      Why would the spacecraft start rotating? Never mind.

      • Assume a ten percent loss ratio. It's still a cheap way to send up easily replaceable material.

        10% would be a damn good lossage factor. Many engine techniques get only about 30-50% efficeincy out of their fuels.

        Why would the spacecraft start rotating?

        A rocket's trajectory usually takes it up to optimum height where it then rolls to a parallel course with the Earth. During this portion of the launch, the rocket is throttled up to maximum power so that it can achieve orbital velocity.

        • 10% would be a damn good lossage factor.

          Sigh, I'm worse communicating than that ex vice president, whatever-his-name-was.

          The original post took up ways for a launch to fail. I was trying to make the point that these launches can be done every hour, maybe multiple times. So even if it should have a high loss rate, it's a good deal.

          I realize a rocket could start rotating outside of the atmosphere. Why is this kind of rocket so much more probable to do it that it will be a killer for the design?

          • The original post took up ways for a launch to fail. I was trying to make the point that these launches can be done every hour, maybe multiple times. So even if it should have a high loss rate, it's a good deal.

            Ah. Sorry. 10% is actually high for most launchers today. They've gotten pretty good at building them. :-) The problem tends to be that the cargo is worth far more than the rocket. e.g. If my comsat required for 5th generation cell phones blows up, then I'm out of the market. By the time I build an
            • I took 10% out of the air as a high loss rate, for my argument.

              the cargo is worth far more than the rocket.

              I've seen people that know much about this claim that if the prices for a launch went down, they could build satellites much, much cheaper.

              Partly a similar reason to that servers with high availability are much more expensive. And partly because of being able to "throw weight" at a problem and e.g. standardize on parts.

              Yes, I of course know that a rocket has to change orientation. What I do

  • Efficiency (Score:2, Insightful)

    by Tragek ( 772040 )
    Since when does one call 40% efficiency efficient? If a bicycle had that kind of efficiency, no one would ride them!

    When are lasers going to finally hit 'real' efficiancies?

    • Re:Efficiency (Score:1, Insightful)

      by Anonymous Coward
      Cars in normal operation are way less than 40% thermally efficient. I guess nobody drives cars.

      Efficient use of expensive resources drives decisions. Efficient use of cheap resources doesn't get any respect.

      40% could still turn out to be cheaper than rockets, even if the rockets were more efficient, due to all the other factors involved.

    • Re:Efficiency (Score:2, Insightful)

      by Brianwa ( 692565 )
      Your average car engine gets only about 20% efficiency, yet many many people continue to ride in them...
    • You can only be as effecient as the pumping levels. It turns out that wallplug efficiency limits systems to about 50%.
    • Since when does one call 40% efficiency efficient?

      Since efficiencies of less than 1% are typical for most lasers that aren't diodes or CO2, that's when.

      And since the _energy_ efficiency of chemical rockets is multiplied by the mass fraction (typically 5% or less), that's when.

      If you can get a 40% efficient laser dumping most of its energy into either a carried-hydrogen stream with an Isp of 600-900, you get a system that is _vastly_ more efficient than chemical rockets.

      It remains to be seen if this end
  • Ive heard about using a cannon to launch satalites and other rockets-- eg, get them high up as possible, then have the engines take over

  • Go back to your SF (Score:3, Informative)

    by unfortunateson ( 527551 ) on Saturday July 10, 2004 @10:32PM (#9663944) Journal
    Dean Ing's "The Big Lifters" [curiocornerbooks.com] talked about this 15 years ago, with a prototype unit that used a maglev train to push the orbiter to just about transsonic, a short-lived ramjet booster to get upright, then hit it in the @$$ with a laser to get to orbit.

    Ing talked about other interesting transportation options in that book, such as delta dirigibles to handle cargo off-load from moving trains, and engineering trucks for intermodal hauling over short distances that are better at city driving than highway. Good socioeconomics for hard sci-fi.

    • Re:Go back to your SF (Score:1, Informative)

      by Anonymous Coward
      Where do you suppose Ing got the idea? Jordin's been working on it the mid-80s.
    • And if you read the dedication, "The Big Lifters" is dedicated to me -- well, to LLNL, where I was just starting what became the SDIO Laser Propulsion Program.

  • X Prize Proof Of Concept (Score:5, Funny)

    by SEWilco ( 27983 ) on Saturday July 10, 2004 @11:55PM (#9664375) Journal
    Everyone bring two laser pointers to the Las Vegas water tower on August 1st for an X Prize attempt.

    Make sure you bring enough extra batteries for the landing, rewelding the tower, and the second required flight.

  • I have an Idea, it's probably been proposed before but, i'm wondering if anyone with a better physics backround could verify or deny this idea. Basically For Satalites/already in space systems. Is it feasible to use some sort of lazer propulsion system? I.e Light energy is the most readily available source of power (through solar panel) Could A series of high powered lazers be used to hit an adjustable pannel (also attached to the satalite) with enough force to move the satalite. Thereby getting rid of any
  • Didn't Russia launch a solar sail probe a few years ago, while sticking us with their Soviet boondoggle tech in the Space Station? Now we're cleaning up their expensive, tardy messes at the ISS, while they're planting *their* Red, White and Blue flag in the rest of the Solar System. They're always first out there - we should be capitalizing (pun intended) on the chance to be first to be second, learning from their mistakes. Not repeating them at the ISS.

  • Distributed Production Economics (Score:3, Interesting)

    by whitis ( 310873 ) on Sunday July 11, 2004 @06:30AM (#9665534) Homepage

    One nice thing about this approach, compared to many other systems, is that it could lend itself to distributed production which would spread wealth around to many companies and local economies rather than concentrating wealth in the hands of a few. The design requires over 2000 laser/telescope modules each in an intermodal container. Instead of having one contractor build them all, imagine having a hundred contractors (average two per state), perhaps many in university towns, each building 20 units to a common design. Move the factory to the workers instead of vice versa. Each production facility would have a large flatbed CNC mill, mirror grinder, welding equipment, and a small electronics shop or would be a consortium of local manufacturing shops with excess capacity (i.e. a machine shop and a welding shop). Many more smaller companies would produce subassemblies. Assuming that production was not continuous but came to an end, making them all in one factory would require large numbers of people to move to one city which would then have a large layoff and unemployment that the local economy could not absorb at the end of production. By spreading it out, local economies would be better able to absorb the layoffs. And the number of layoffs would actually be reduced because the 100 different companies could each have different transition plans to developing other products so you wouldn't need another project of the same magnitude to absorb the labor and manufacturing surplus at the conclusion of the project. The distributed surplus of manufacturing capability would then spur innovation in other areas. I am thinking that each factory would have, rather than single purpose fixtures, a more general purpose programmable production ability (such as CNC tools) that would need little retooling to work on other projects. Also, many of the manufacturers would be applying existing facility and labor surpluses to this project. Manufacturing the individual lasers would still be handled by a small number of plants with a few more turning them into laser arrays. Specialized tasks like silvering the mirrors might be cheaper to do by shipping an intermodal container based factory with metalization equipment to the various factories or by shipping the mirrors in to a central site. Mass producable electronics like tracking systems could be manufactured at a smaller number of plants and shipped to the individual plants. The honeycomb mirror blanks could be manufactured by the University of Arizona Mirror lab, Corning, or similar glass manufacturer and possibly spin cast to approximate curvature. When the booster modules are completed a tilt bed truck picks them up and transports them to the nearest railroad container facility to be put on a rail car for shipment to the final laser site.

    The only huge scale production operation would be if you decided to build a nuclear power plant to power the system.

    The individual launch craft would be small enough that their manufacture could be distributed as well.

    The distributed nature would reduce cost overruns which are routine for large contractors since how many systems were ordered from each manufacturer would depend on the quality and cost of the systems they produced. The first (prototypes) would necessarily be built in small shops; this could be extended to final production and still keep a reasonable economy of scale by using flexible tooling and centralized engineering costs and by eliminating beaurocracy and monopolistic thinking and by reusing idle factory spaces around the country. The quantity of units isn't really high enough, anyway, to fall into the economy of scale of a fixed purpose production line (like for an automobile).

    I imagine the laser site looking like a freight yard with perhaps 20 widely spaced parallel sidings with 100 containers each. The added expense of leaving rail cars under each container is offset by the ease of replacing modules although you could use a crane to move the container onto smaller wheel

  • Basically, there are two types of laser rocketry, as defined by fuel: air-burning, as used by Dr. Leik Myrabo and has been seen on tv; and soild fuel (usally a dense metal) burning, as being developed by Dr. Andrew Pakhomov at the University of Alabama in Huntsville. The problem with the Myrabo method is that the laser is tuned be absorbed by the air, and thus is inefficent over long distances. Ablative laser propulsion doesn't have this problem. It is however still very much theoretical: I've seen their fi

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