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Space

Lunar Lasers 405

Posted by michael from the keep-your-laser-handy dept.
Two different articles about building lasers (well, lasers and a maser perhaps) on the moon. Reuters has a story about a potential lunar power plant, creating electricity with solar panels and beaming it to Earth with microwaves. Space.com has a piece about building a sort of super-sized Star Wars program on the Moon, giant lasers set up to blast incoming space debris and not, of course, anyone here on Earth.
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Lunar Lasers

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  • Why bother? (Score:2, Insightful)

    by shaunak ( 304231 )
    Does it not seem better to build solar arrays in the deserts near the equator (max sunlight) and have the energy transported through a smaller distance than from the moon?
    And why is this news for nerds?

    • Re:Why bother? (Score:5, Funny)

      by Anonymous Coward on Thursday December 13, 2001 @03:08PM (#2700122)
      And why is this news for nerds?

      Yeah, only jocks discuss lasers on the moon. Us nerds should stick to talking about football and women and beer.

    • Re:Why bother? (Score:2, Informative)

      by blosscore ( 459437 )
      The moon has not atmosphere silly, so the rays coming from the sun are not deflected by anything so that solar panels will be able to absorb more light than they would just about anywhere on earth.

      • Re:Why bother? (Score:3, Informative)

        by Rand Race ( 110288 )
        Actually, the moon does have an atmosphere. While it is very thin, about a billionth of the terran atmosphere's density, it extends over 5000 miles up from the lunar surface (as compared with about 70 miles for the earth's). But you are correct in that the effects of the lunar atmosphere are quite minimal. Orbital stations are still a better option IMHO, they have far less particulate interference than even a moon based collector, a far shorter transmission distance, and can spend far more time in direct sunlight.

    • Re:Why bother? (Score:2, Informative)

      by pete-classic ( 75983 )
      Does it not seem better to build solar arrays in the deserts near the equator (max sunlight) and have the energy transported through a smaller distance than from the moon?

      Of course we have a little thing in the way called an atmosphere.

      And why is this news for nerds?

      Uh, lasers, space, science (sci-fi-like at that). I'm not sure what could be nerdier.

      -Peter

      • Re:Why bother? (Score:2, Insightful)

        by hoggoth ( 414195 )
        > Of course we have a little thing in the way called an atmosphere.

        Yeah, everyone knows SUNLIGHT can't make it through our atmosphere.

        The article states that the maser beam's power would be roughly 20% of sunlight. Therefore a solar array sitting on the ground working at 20% efficiency would be able to collect the same amount. A series of them at various equatorial points around the Earth would be able to collect at all times.

        • Some (most?) sunlight makes it through. A much lower percentage of solar radiation (less than half?) makes it through.

          So, would you rather have twenty percent of a little or a lot?

          -Peter

  • Microwave (Score:2, Insightful)

    by Apreche ( 239272 )
    Exactly how does microwaving electricity work? I mean You have a powerplant on the moon. That powerplant zaps a zillion microwaves that the earth. What is exactly involved in catching them and turning them into electricity? Don't tell me they boil water and spin turbines. And what if they miss, like in sim city 2000. Big boom!
    • Well, you can't just string high-tension wires from here to the moon (not easily anyways). So, instead 1) Take the sunlight, convert it to electricity, 2) Convert that electricy to microwaves so they can be transmitted (in a focused beam) across space to Earth, 3) Collect those microwaves in a collector dish, and convert them to, oh let's say heat, 4) Convert that heat to electricity (like in a coal powered power plant), but much more environmentally friendly.

      AND NO, we would not irradiate or cook the Earth.

      • They think power lines are bad? I can just imagine the cancer cluster surrounding the receiving station.

        As far as cooking the earth, I'm not suggesting that it would burn the whole planet, but think about the starving families we could feed by pointing it in the middle of the ocean and boiling up a whole bunch of seafood. Send a couple boats out there to skim the surface after its done, then just pack on ice with cocktail or tartar sauce.

    • Re:Microwave (Score:5, Informative)

      by mbessey ( 304651 ) on Thursday December 13, 2001 @03:14PM (#2700190) Homepage Journal
      Microwaves are easy to recieve - you simply stretch out a wire between two insulated poles, and the power just flows. That's the big advantage of microwaves over other power transmission possibilities.

      Granted, given the spill-over from the "concentrated" beam of microwaves, you'll probably have to use some frequency that's not very popular for communication, but it's probably do-able.

      The people who are worried about power-line emissions would probably go insane over this, though - the exposure levels would be MUCH higher.

      -Mark

      • We already have antennas (Score:4, Interesting)

        by KarmaBlackballed ( 222917 ) on Thursday December 13, 2001 @03:44PM (#2700401) Homepage Journal
        you simply stretch out a wire between two insulated poles, and the power just flows

        You bring up an important point: powerlines and phone lines already cover the globe. They will pick up the power too. This may not be a good thing.
    • No, they don't boil water and spin turbines. What you do is to take the microwaves, catch them with an antenna (they are radio, after all) and rectify them with a diode (what you get is just very, very high-frequency alternating current which can be converted to DC with that most simple of all semiconductor devices).

      Before you go "Bah", please understand that this has actually been tested over an atmospheric path crossing as much air as you'd need to from a typical orbit, and efficiencies around 80% were measured.

  • hmm. (Score:3, Funny)

    by raindog151 ( 157588 ) on Thursday December 13, 2001 @03:07PM (#2700114) Homepage
    i saw this in highlander 2 i think. it didn't work out too good.

  • Actual story? Or... (Score:3, Funny)

    by Ric0chet ( 110522 ) on Thursday December 13, 2001 @03:07PM (#2700119)
    ...a strange social experiment by the /. team to see how many people will come up with the same joke in a given period of time?

    Hmmm...
  • Why not an orbiting satellite. His quote in the article was: "It's really a very cost-effective proposal".

    Why waste all that energy to go to the moon, and only get 14 days out of 28 of sunlight to convert to energy... and beam it half a light-second back to earth? A series of satellites would seem 1) More cost-effective, 2) faster and, 3) would not require a new moon program.

    If we had existing infrastructure there... sure. But otherwise it's just a huge waste.

    • A geo-synchronous satellite would be a lot easier to aim at a stationary ground-based receiver.

      Seriously, I've heard this exact same idea before, but with geosynchronous satellites in place of "the moon", which sounds kinda silly in the first place. Of course it still has the same dangers.
      • There aren't really any dangers. The power density of the microwaves that the clued up people talk about are only the same as the power that is emitted by cellphones; you could stand in the beam with no protection and no problems at all.

        There's no physical way to make the antennas focus be any tighter than that given the size of the antenna and the wavelength that is proposed; and the power delivered is limited by the size of the solar panels.
    • Most conceptions of orbital power stations rely on a mylar baloon of sorts used as a reflecting dish (think a sphere, half clear, half reflective... point the clear end at then sun and you've got a dish... well... kind of anyhow, more an elipse than a sphere)

      Anyway, since this is space we're talking about and thus we're working in freefall, the entire collection array can simply be this balloon. This drasiticly cuts costs. Now all you have to do is beam it back.... these can be launched without human beings going up at all.
    • What does the distance to the moon have to do with anything?

      And the reason it would be cheaper is that the moon already has a 'structure' we can build upon. Setting down a square mile of solar cells would be a lot easier then building a square mile rigged structure.
      • Even the best laser/maser loses focus over distance.

        Like mail order purchases, it's not the item cost that's the killer, it's the shipping fees. Much cheaper to ship a few satelites into orbit that to ship them to the moon.

      • Yes, but the power beaming antenna would have to be much bigger because the moon is much further away- and the antenna would have to be much more expensive because you have to steer it to point at the right points on earth due to the rotation of the earth; incidentally I've looked into steering mechanisms and whichever way you cut it, its very expensive.

        The whole point about geosynchronous orbit is that it doesn't need steering because the satellite doesn't move relative to the earth- that plus the fact it gets twice the sunlight and hence twice the power.

  • all I wanted was a frickin "Laser" (Score:3, Funny)

    by jafac ( 1449 ) on Thursday December 13, 2001 @03:09PM (#2700137) Homepage
    (insert finger-quotes here)

  • This is a weapon of massless destruction (Score:4, Interesting)

    by KarmaBlackballed ( 222917 ) on Thursday December 13, 2001 @03:10PM (#2700143) Homepage Journal
    The power sent as microwaves must be focused into some reasonable area unless they propose having antennas nearly the size of the moon on earth.

    1. How will they focus the beam on receptor antenas?

    2. How will they keep airplanes from flying across the beams?

    3. Will they coordinate with satellite operators so they can avoid the beam too?

    The only way for this not to harm you would be for it not to strike you. Early radar technicians learned about microwave cooking standing in front of such beams
    • 1. How will they focus the beam on receptor antenas?

      By any number of means. Mirrors, lenses, etc. A maser beam will not spread out too much.

      2. How will they keep airplanes from flying across the beams?

      They probably won't. If the idea really gets off the ground, it wouldn't be hard to equip airplanes with microwave dissipation grids. It'll heat up the grid but the airplane will cross the beam very quickly.

      3. Will they coordinate with satellite operators so they can avoid the beam too?

      This is the one major problem. The effects would vary depending on what sort of electronics the satellite is carrying.

      The only way for this not to harm you would be for it not to strike you.

      The article states the beam would have an areal power of about 20% that of sunlight. This is approx. 270 watts per square meter. Pretty strong, but since the microwave beam will be collected, the only way you could be exposed to it would be to stand at the collector.

    • Weapon? Calm down. The article talks about a beam that has 20% of the sun's power density, i.e., less than 150 W per square meter. Hardly enough to kill anyone.

      Of course, planes should avoid the beam.

      But overall, I am skeptical about the project. Not about its feasability of safety (mere engineering problems), but over its economical realism. Why bother going to the moon? If microwave-beamed power production becomes a reality, then a geosynchronous satellite is the obvious answer.

      Installing a solar power plant on the moon would make sense only if raw materials could be mined and processed on the moon instead of being lifted off from the Earth's gravity well. Otherwise, installation on the moon would introduce yet another gravity well to overcome each time you have to move something back and forth (and a power plant would require shuttling personnel and material constantly). At least, a stallite doesn't require you to fly rockets back and forth from the moon surface.

      -- SysKoll
      • The article talks about a beam that has 20% of the sun's power density, i.e., less than 150 W per square meter.

        If this is so, then why bother with this system at all? A direct solar collector on earth could generate nearly as much energy per square meter as the receiver antenna. Even if you needed 5X more solar collector area on earth as microwave receivers due to efficiency, night and clouds, you'd still come out ahead because wouldn't need to pay interest on a trillion dollar lunar infrastructure.

        • Microwave mesh antenna is a lot cheaper than solar collectors on earth for same area.
        • You can't rely on the solar energy on earth. The whole point about beamed power is that it is 24x7x365.25.

          The problem with solar power on earth is that it isn't available at night. Large scale energy storage on earth is exceedingly non trivial; otherwise solar would be used more. In fact solar gives you the most power midday where you often need it the least.

          Also, beamed power is available anywhere on earth. I live in the UK; trust me when I tell you that you don't get enough power in winter time from solar (ok, I lie slightly, one guy covered his entire roof, and I mean entire roof with solar panels, at some unspecified cost, probably in the high tens of thousands; he still needs a power grid connection at night; he just about breaks even energy wise, but monetarily- nope.)

          Beamed power would actually break-even after about a decade of use, the studies show.
        • If this is so, then why bother with this system at all?

          Well, considering the price of industrial real estate, the cost of an Earth installation is still staggering. A space installation, as you mentioned, is more efficiently (no night, no weather). If the cost of a high power space-based microwave beamer system is reasonable, then it makes sense.

          But first, of course, we'd need cheaper space access cost. The cost of lift-off per kilogram that NASA can offer is heavily subsidized, and even so, it is totally prohibitive. The ruinous shuttle has to go, and some form of price-lowering competition has to take place. We are still very far away from this.

          Still, when you see the cost of orbiting even an experimental microwave beam plant, you wonder if we'd not be better off investing this pile of money into, say, fusion research.

          -- SysKoll

    • Re:This is a weapon of massless destruction (Score:5, Informative)

      by Fenris2001 ( 210117 ) <[ude.tmn] [ta] [sirnef]> on Thursday December 13, 2001 @03:46PM (#2700408)
      Answers to safety questions -

      1. Focus - the beam will most likely be a maser, or microwave laser. Given a reasonable size emitter in geosynch or elliptic earth orbit, the footprint on the surface of the planet is only a few kilometers wide, and has an energy density of perhaps ten to a hundred watts per square meter.

      2. Guidance - the same way they keep aircraft away from anything else - tell them not to go there. Note that this isn't really a problem, as the metal skin of an aircraft would deflect the beam.

      3. Of course they will coordinate with other satellite operators. Although, if some satellite DID accidentally cross the beam path, it wouldn't necessarily be harmed, for the same reasons as 2.

      The proposals I've seen for this (including a gov't study in the Sixties), all addressed the safety question. The REAL question is whether or not this can be done ECONOMICALLY - it's no use if the power so produced is ten times more expensive than fossil fuels (though note that such a scheme becomes more attractive as fossil fuels become more expensive...). The most attractive source of building materials for the solar cells and support hardware is not the Earth, but asteriods that cross or come near the orbit of the Earth - they contain all the necessary elements (silicon, iron, hydrogen, carbon, etc.) to make a solar power satellite in orbit, instead of having to haul every component up from the planet.

    • IT IS NOT A WEAPON OF MASS DESTRUCTION. It is not even a weapon.

      The beam only needs as much power/m^2 as a cell phone. You can stand right in it with no ill effects. Birds, aeroplanes can fly/sit through/in it without harm. Even if the beam 'slipped' nobody would notice much; the odd EMC problem is all, but realistically the beam would be switched off before it went anywhere.

      Maybe if there was a hundred of them and they were all lined up to point at the same point on earth; but even then a thin layer of silver foil is all that is needed to defend against this extremely unlikely scenario.

      Compare this to a microwave oven with 500-1000 per square foot. Turn that power down by 100 times. How warm does your food get?

    • Nobody's gotten this right yet (Score:4, Informative)

      by Spamalamadingdong ( 323207 ) on Thursday December 13, 2001 @04:26PM (#2700623) Homepage Journal
      1. How will they focus the beam on receptor antenas?
      There are some pretty simple ways of doing this. One is to send a "pilot beam" from the receiver to the transmitter, and use it as a phase reference. Using techniques of phase reversal (see this guy's bio [usc.edu]) you can create a coherent beam at the other end of a "lumpy" medium like wavy glass (or the ionosphere, or a chicken [see the bio]).
      2. How will they keep airplanes from flying across the beams?
      They won't; the beam intensity isn't sufficient to be a problem. It just struck me that it would be ideal to locate airports in the middle of the receiver farms, because that will keep development from encroaching under the approach and departure paths and creating noise problems and threats to persons on the ground from crashes.
      The only way for this not to harm you would be for it not to strike you. Early radar technicians learned about microwave cooking standing in front of such beams
      There are easy ways to avoid it striking you (a wide-brimmed tinfoil hat might actually have usefulness against something in the real world). The best is to make sure it can't go anywhere other than where it's intended, using a technique like an encoded pilot beam. Turn off the pilot beam, the transmitter no longer has a phase reference, the various transmitter sections go incoherent, the power gets radiated all over the sky and falls to minuscule levels on Earth.

  • If they don't bite, lower the price... (Score:5, Interesting)

    by ObligatoryUserName ( 126027 ) on Thursday December 13, 2001 @03:13PM (#2700174) Journal
    The solar power plant on the moon idea has been around for quite a while, but the last time I heard of it, the estimated cost was more than a trillion dollars (I seem to recall it being closer to 2 trillion dollars). Even though it cost so much, the scientist (I can't remember who it was, so it might be the same guy) said it could make back all its costs in under a year by selling power to everyone on Earth at a rate that was lower than what we would pay otherwise.

    What I'm curious to know is has the cost of space missions gone down so much since then that it can now be done for the $59 billion listed in the article, rather than the >$1 trillion number cited a number of years ago, or is there some new trick (sure sounds the same), or is this guy just making up a lower number so that people will actually listen to him? Anyone out there heard of this Prof. Criswell before? I'd really like to believe that this is a viable option.

    • I have mentioned this in the other, almost identical, articles on beaming power to earth from space.

      There was a proposal for the 1982 Knoxville World's Fair to do this from a satellite and have the microwave beam land on a mesh reciever.

      The pesky problem had something to do with safety of birds passing through the beam, since they do not read Notices to Airmen and have no concept of "no fly zones".

      The problem is compounded by basing this on the moon, since it is not geocincronious and the beam would have to continuously move to stay on target. It can only be on one target about 12 hrs/day or so too. (Yes, they CAN generate through the whole lunar cycle since the collectors can be placed all around the moon and only the transmitter has to be on the near side)

  • Pointless (Score:2, Funny)

    by mischief ( 6270 )
    Maybe one day we'll be able to illuminate the earth by pointing the moon this way!
  • I'd hate to be one of the sorry bastards that has to live near the receiving dish.

    On the bright side, at least you'd never have to worry about heating bills for your home.

  • As far as they don't point this dam microwave beam near home (about 500km) I don't care.

    Gee, what's next? Alien Invasion that burns everything into Trees? Life imitates the games, maxims really hited the bullseye this time.

  • 20 percent of noontime sunlight (Score:3, Insightful)

    by vlad_petric ( 94134 ) on Thursday December 13, 2001 @03:26PM (#2700279) Homepage
    AFAIK 20 percent is roughly the efficiency of a photovoltaic cell. So you'd need a close to 100% efficiency for a rectenna just to break even with photovoltaic cells (from a surface standpoint).
    It may be cheaper to build rectennas, however I'm not convinced how it could break even in 5 years with >50 billion spent.

    The Raven
  • Criswell's idea might seem loopy, but he insists that it would be achievable if the U.S. government would commit to spending the money -- estimated at roughly three times the $19 billion budget of the Apollo space program.

    What the heck are these people smoking? Do they realize how many standard earth-bound solar cells and wind generators $57 billion could buy?

  • I've got an even better idea (Score:5, Insightful)

    by SIGFPE ( 97527 ) on Thursday December 13, 2001 @03:26PM (#2700287) Homepage
    Why not spend $50,000,000,000 on solar panels for use on Earth. This proposal has a number of cool features:
    1. You don't have to send lots of equipment up to the moon
    2. You don't have the hassle of building microwave transmitters and receivers to transmit the energy to the Earth
    3. They couldn't easily be hijacked to make a nasty weapon
    4. The equipment would be easy to service. You wouldn't need regular flights carrying crews to the moon.

  • So where's the energy density? (Score:3, Insightful)

    by Myself ( 57572 ) on Thursday December 13, 2001 @03:31PM (#2700319) Journal
    The microwave energy beam, which could pass through rain and clouds, would have the intensity of about 20 percent of noontime sunlight...

    Okay, so if this thing is so much weaker than sunlight, why wouldn't we just use terrestrial solar cells to receive existing sunlight rather than some receiving station for funky microwave power?

    Come on! In order to be even slightly useful, the energy beam coming back would have to be terribly intense, which would make it terribly dangerous. Even noontime sunlight can be nasty, ask a suburban sidewalk ant or any pale-skinned swimwear-clad human.
    • because we can much more efficiently turn that microwave radiation into electricity?

      IT's a different frequency.. we can much more efficiently use it to transmit power.

  • Watch Your Eyes (Score:4, Interesting)

    by Myriad ( 89793 ) <myriad@noSPAm.thebsod.com> on Thursday December 13, 2001 @03:32PM (#2700326) Homepage
    It seems inevitable that whenever there is a story regarding lasers we get to see all sorts of silly posts about blasting people with laser.

    Even antimissle lasers have a long way to go. Between power requirements, beam handling, divergence, and atmospheric interference, lasers do not make great destructive weapons.

    However, they would be damned good for some nasty tricks like blinding the enemy army (or, unfortunately, civilians).

    Take this scenario: a bomber/cargo style aircraft has been outfitted with a large infrared laser (similar things have been done). Fly said aircraft over the people you wish to 'zap'. Release some fireworks or other attention getting devices and when the crowd looks up turn on and start scanning the laser.

    Since the laser is infrared nobody would know they are being exposed to blinding levels of light, nor would the blink/aversion reaction take place. By the time you noticed anything the permanent damage has been done. Scary huh?


    Another scenario under serious consideration by police (at least here in Canada, I've participated in meetings on the subject) is the use of lasers against commercial aircraft. The idea isn't to shoot down the aircraft, but to scan at temporarily blind the pilot during final night approaches. The effect is like someone flashing a camera flash in your face when your in a dark room.

    As the few moments prior to landing are the most critical, distracting and flash blinding the pilot could easily lead to the plane crashing.

    Worse, new solid state lasers are available in the 3watt (plenty of power to cause permanent blindness) range and can be powered off a car with an inverter. Simply park at the end of a convenient runway at night, plug 'er in and away you go. Ok, so it's not quite that easy, but the concept is...

    Doesn't that all just scare you a bit more than some silly death ray?

    Note: after saying all that I want to point out that I do not support the insane regulations placed against the use of lasers in the United States by the CDRH. It's totally ridiculous and overzealous.

  • It would be overly inefficient to build facilities like that on the moon and then beam the power all the way to Earth. Not only would one have to contend with the lunar atmosphere, which while rarer than Earth's is much thicker, but the distance involved would limit the amount of power that could be transmitted.

    It would be much better to build solar power satellites and launch them from Earth. The satellites would require less material than similar facilities on the moon, and though some of them might be manufactured from lunar material, the infrastructure necessary would be enormous. The distance would less than 1/10th as great, meaning at least 100X higher efficiency.
  • The project is receiving unexpected economical support from this [austinpowers.com] organization.

  • Two dumb ideas (Score:5, Informative)

    by markmoss ( 301064 ) on Thursday December 13, 2001 @03:38PM (#2700368)
    If you are going to do this beamed microwave thing, build it in Earth orbit, closer to the target. (distance)*(wavelength)= k*(diameter of transmitter aperture)*(diameter of beam at target), where k is a constant somewhere between 1/3 and 3. I think the moon is about 250,000 miles or 400,000 km away. So to focus a 30GHz (1 centimeter wavelength) microwave beam down to a 10 km spot on Earth takes an antenna about 400m across. Or in units the average American understands, a football-field sized antenna would put most, but not all, of the transmitted energy into a 10 mile wide spot. This whole area would have to be blanketed with receiving antennas (expensive!). And people living 20 miles away would be measuring the leaking energy and suing every time they got a cough. (Birds would be safely building nests on the antennas, but American trial lawyers never let science get in the way of a deep-pockets lawsuit.)

    The best place for a solar power satellite is probably geosynchronous orbit (40,000 km). This needs a football-field sized transmitter and a mile-wide receiver; still pretty big, but maybe manageable. And the transmitter and receiver don't move relatively. A lunar array would have to keep switching between different receivers as the Earth turns. An SPS in a lower orbit would also have to keep switching receivers, but at least it would have smaller antennas.

    A solar plant in orbit is in sunlight almost all the time (depending on distance from earth and orbital particulars, it might spend a few hours a year in earth-shadow). On the moon, two weeks out of every four is night.

    The laser installation would also work better in a medium-height earth orbit, where it's solar panels were powered all the time and it was much closer to the targets. At least, I assume that it isn't meteroids headed for the moon that this is supposed to shoot down?
    • "The best place for a solar power satellite is probably geosynchronous orbit (40,000 km). This needs a football-field sized transmitter and a mile-wide receiver; still pretty big, but maybe manageable. And the transmitter and receiver don't move relatively. A lunar array would have to keep switching between different receivers as the Earth turns. An SPS in a lower orbit would also have to keep switching receivers, but at least it would have smaller antennas."

      There is one advantage of the moon-based solution that isn't mentioned, though: The moon's orbit won't degrade any time soon. However, even geostationary satellites need to be replaced regularly every few years. So you either keep switching easily-maintained ground stations or you keep refitting and/or replacing hard-to-maintain orbital platforms.

      "At least, I assume that it isn't meteroids headed for the moon that this is supposed to shoot down?"

      I was under the impression that you were supposed to detect these things outside of the earth-moon system, hopefully at least two weeks outside it.

  • An Old and Silly Idea That Won't Go Awayt (Score:3, Insightful)

    by Prof_Dagoski ( 142697 ) on Thursday December 13, 2001 @03:39PM (#2700374) Homepage


    Gawd, I've seen this idea so many times before. It's something they always bring out as a gee-whiz justification of manned space exploration. Y'know, just to show that space has practical applications. The arguements against are pretty persuasive. Safety, cost, and effectiveness. I don't buy it and didn't even think much of it as a kid. I just with these people would stop insulting our intelligence. A better way to address power consumption through technology is in effeciency. A good example that works is the new compact flourescent light bulbs. I've saved my bill before and compared it to after I swithced my apartment over to them. My power bill went down by a little less than half. Pretty nifty. I figure if we can do more with less, we can satisfy our needs for more people, and we can do it without crazy crap like this. In any case, some of the new home solar products are making this thing a moot point. In the meantime, there's lots of better reasons to explore and develop space.

  • the obligatory joke off the phrase "lunar laser" (Score:3, Funny)

    by Have Blue ( 616 ) on Thursday December 13, 2001 @03:56PM (#2700475) Homepage
    CHA!
  • Remember that no human has walked on the moon in 25 years, and while they were there, astronauts did "advanced moon things" like picking up rocks and playing golf and not building a habitat that could sustain life for more than 3 days.

    I want to see some of these lazy-ass theorists postulate something useful like building a space station that's worth the money we spend. Yipty-freaking-do! You can go to the ISS, live for 6 months, and do science (play with toys)!

    Listen up, NASA. If you can't build anything with a space station it is just another Mir or Skylab destioned for "decommissioning" in fireballs over the Pacific. Long-term planning is not pie-in-the-sky postulating, however much slashdot thinks it is.

    Here is my plan:

    1) Build decent Space Station around Earth with *construction capability*. It doesn't have to be great at first. You could use it to build a better one if it isn't good enough.

    2) Build reliable Earth-Moon transport.

    3) Build decent Space Station around Moon.

    4) Build decent Moon Station.

    5) Then (and only then) think about stupid Moon Weapons and Power.

    A couple of geeks in a room postulating about moon weapons is not science no matter how much they are paid for it.
  • The main problem with solar power systems, at least in places like the Mojave Desert where they've actually been deployed, isn't weather. It's the day/night cycle. You only get about 1/3 of the peak power of the system, on average, even in perfect sunlight. That's because the collecting area is rotating (with the Earth) and almost never has an ideal presentation angle. Then, of course, you get NOTHING during the night, when the Earth is between the collectors and the Sun.

    These lunar systems will suffer from the same problem: at most about 1/3 of the peak collecting power will be available on average. Rectennas are pretty cheap compared to solar arrays, but it seems to me that each joule you make on the Moon and beam back to Earth is a pretty expensive one.

    Never mind that the beam has to track stations and (to prevent wasting the resource during night from the first receiving station) has to jump between receiving stations that are widely separated in longitude. Lots of opportunities to screw up and irradiate populated areas.

    The proprietors say the microwaves are perfectly safe for people -- but the government guidelines for microwave exposure are based on bulk heating effects, not on any special physics from the waves themselves. That's a bit fishy in itself -- but what about places like hospitals that are filled with sensitive life-support equipment? I can imagine Homer Simpson on the Moon accidentally beaming New York and killing thousands of pacemaker owners and hospital patients.

  • Problems (Score:5, Interesting)

    by saider ( 177166 ) on Thursday December 13, 2001 @04:16PM (#2700584)
    Has anyone built a 100% automated large scale power plant? Even here on Earth, such a task is daunting. Saying that it can be easily done on the moon, and done cost effectively is like saying that I could build cheaper cars on the moon because my machinery will only have to cope with 1/6th of the gravity.

    "But satellites and the space shuttle use solar power all the time." They also have either a 5-10 year lifespan or are serviced regularly. The article said that it could be profitable in 5 years. So when it finally becomes profitable, many of its components will be nearing the end of their lifespan. Then you have to chunk down some more money to build a replacement.

    Nevermind that there will still need to be multiple ground stations in remote areas to catch the radiation. The moon is not geosynchronous. Build a station at the poles you say? There goes your costs again. Also, say what you want about safety, nobody will want to live near these things. And they will have to be in different countries which brings politics into the mix.

    This is pie-in-the-sky dreaming. If you ask me, I think the money is better spent designing and running a good nuclear power plant or for some fusion research.
    • The Space Shuttle does not use solar power, it runs on fuel cells and batteries. The bay doors of the shuttle have radiators on them, not solar panels.
  • ...what if Chairface Chippendale gets ahold of this? Will he still try to write his name on the moon? Or will he use the moon to write his name on Earth?
  • All your "moon base" are belong to us!!
  • Wil Wheaton's interview [bbspot.com]:

    • BBspot (11): Tell us why you're doing WilWheaton.net [wilwheaton.net] and about future plans for you and the site?

      Wil: It's all part of my Bavarian Illuminatti-driven plot to rule the world. Now that you've read that, we're coming for you with our Orbital Mind Control Lasers.

    You're behind this, aren't you Wil?
  • It's quite a silly comment, "... set up to blast incoming space debris and not, of course, anyone here on Earth".

    Even if the laser were powerful/accurate enough to do this, why "on earth" would we use an insanely expensive weapon such as a lunar-based laser to strike a target on the ground? It's simply ridiculous when you consider that there are far more cost-effective ground-based ways to do this. Anyone who talks about using these from space, I think, has not considered this.

  • in other news... (Score:3, Funny)

    by stinkydog ( 191778 ) <sd@strangCHEETAHedog.net minus cat> on Thursday December 13, 2001 @04:50PM (#2700783) Homepage

    Since the Lunar power Station came online...

    Aluminum Hats a no longer for wackos

    Check out those Northern Lights (in Florida)

    Forget four poster bed sleep in a faraday cage

    Metal Orthadonics fall out of favor

    Peeps rise up from their cellophane prisons and attack their masters

    Floresencet Lights no longer need to be connected to the power grid

    Just because we can does not make it a good idea [utwente.nl].

  • NASA toyed wih the idea of microwave solar sattelites back in the 70's and 80's. several mock-ups were even made.

    they just wondered what would happen when a sattelite got misaligned and cooked a small town in iowa and then canned the idea.

  • Basic Orbital Dynamics (duh!) (Score:3, Informative)

    by Guppy06 ( 410832 ) on Thursday December 13, 2001 @05:00PM (#2700850)
    "a sort of super-sized Star Wars program on the Moon, giant lasers set up to blast incoming space debris and not, of course, anyone here on Earth."

    Does the phrase "tide locked" mean anything to you? The moon's rotation and revolution match each other, so anything set up on the far side of the moon to target incoming debris will never be able to hit earth-based targets, or at least not any time this eon.
  • With a MASER would I be able to cook a turkey at 40 paces? ;-)
  • Microwaves pose real problems as a means of energy transfer. I suggest copper wire. Some of those orange heavy-duty extension cords from Home Depot, for instance. They're durable and affordable. Be sure to unplug them when they're not in use. And be sure to have enough slack so dangerous trasfers of angular momentum don't take place. It would really suck if the earth started spinning twice as fast shortening my sleep AND the moon came crashing into the earth's surface.

    Let's hope those engineers have thought of THAT!
  • David Criswell hired me to do some unrelated consulting during the mid 1980s at the California Space Institute, in part because I was sort of hanging around there anyway as an amateur generally interested in space power, space industrialization, etc. The then editor of Space Power [textfiles.com], Andrew Cutler (also the person who encouraged me to take Presidency of and reconstitute the San Diego Chapter of the L5 Society [geocities.com]), was also at the California Space Institute working on lunar materials processing. Cutler had a running, sometimes acrimonious, disagreement with Criswell on whether space solar power would be more economically gathered in space or on the lunar surface. The dispute was never fully resolved to the satisfaction of anyone to the best of my recollection.

    As best I can recall them, the basic engineering variable traded off were:

    • Lofting material off the moon.
    • Losing solar exposure for 2 weeks out of each month on the lunar surface.

    This has been hashed and rehashed a number of times and it would be very good to have a special conference or online debate directly addressing how one might do economic models that predict which approach is more viable, not just from an operational cost point of view, but from a development-risk or time-value-of-money point of view.

    PS: February of 1982, Jerry Pournelle posted the first Usenet article on David Criswell's lunar solar power proposal [google.com]

  • As they were saying in the 1950s. Was going to
    put oil, gas and hydro out of business.
    However the complex plants and environmental costs
    made it as expensive as anything else.

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