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Lunar Lasers
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.
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?
-Shaunak.
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!
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i saw this in highlander 2 i think. it didn't work out too good.
your jesus is another mans xebu. chew on that hypocrites.
...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...
How you see the world is how the world sees you.
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.
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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
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Give me LIBERTY, or give me a check.
Yes, he's hoping to cut production costs for the third episode. He's thinking that we can just use the sun, instead of those tiny litle models, as Chubacca always tends to crush the model before they finish the scenes...
Um, this is my sig.
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.
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.
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Maybe one day we'll be able to illuminate the earth by pointing the moon this way!
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No, you wouldn't see that on the news, because this "security vulnerability" (MS' future classification of all bugs) is not allowed to be disclosed until MS develops a fix for it and a suitable press release -- something along the lines of "Superhero Microsoft saves lives with laser software upgrade, and also increases the chocolate ration to 5 grams."
The enemies of Democracy are
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.
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But seriously, we'll just have to wait until it overheats itself and blows up, taking him with it.
Apparently you missed this part of the article:
When asked about possible adverse effects a megawatt laser might have on the Earth's weather patterns Prof. Criswell responded, "Why...no...of course not...whatever gave you the idea that this device could be used to hold the world hostage under threat of global weather disasters should they fail to meet my demands? MUHAHAHAHA!"
STOP MISUSING APOSTROPHES, YOU MORONS!!!
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
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?
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(homer):)
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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.
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.
"They do not preach that their god will rouse them, a little before the Nuts work loose." Kipling, 'The Sons of Martha'
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 organization.
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?
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.
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)
Eve Fairbanks says I drive a hybrid!LOL
I think they solved this problem in one of the Batman movies, didn't they? You just have 3 or 4 huge mil-sats up there to initially catch the beam and then pass it around until it gets reflected down to an earth-station just outside of Gotham.
;-)
Of course, you still have to not miss the first satellite.
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.
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Give me LIBERTY, or give me a check.
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.
Scientists restrict study to entire physical universe; creationist
CHA!
Power doesn't just "dissipate". It can be part of a divergent beam, which just gets bigger and bigger, it can be absorbed (converted into e.g. heat) or it can be scattered. In the vacuum of space there is almost nothing to absorb or scatter significant amounts of such a beam, so we're left with divergence. You can keep divergence of a coherent beam to an arbitrarily small amount by making your transmitting antenna larger.
As for building sats in geosync, I agree with you except for the issue of light pollution (but the relay sats required to send power to the half of the earth invisible from the Moon would present the same problem). The real problem is where you get the raw materials for the plants regardless of where they're located. Using near-earth asteroids instead of the moon may be easier and cheaper, avoiding the difficulty of having to work in gravity, at a couple of miles/second delta-V from an earth-return trajectory, and all those other issues. Lunar chauvinism shouldn't blind us to taking the most cost-effective route to the goal.
Scientists restrict study to entire physical universe; creationist
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.
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.
Well, presumably gas won't have run out by the time it's expensive enough to make solar (or this cockamamie moon idea) cost-effective. Why not keep the gas plants around, and when voltage from the solar collectors dips, turn up the heat?
sulli
RTFJ.
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.
Remember, You are unique...just like everyone else.
Didn't you ever see/read 2001? The lunar monolith being exposed to sunrise is a critical plot element.
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Scientists restrict study to entire physical universe; creationist
True, but I remember reading that there are areas at at least one of the lunar poles that get 24x7 sunlight.
Jon Acheson
All opinions expressed herein are my own, and not those of my employers, who are appalled.
...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?
I wish I had a kryptonite cross, because then you could keep Dracula and Superman away.
All your "moon base" are belong to us!!
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Scientists restrict study to entire physical universe; creationist
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.
I only post comments when someone on the internet is wrong.
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.
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Ass.
So far I've gotten all my Karma from telling people they are wrong... :)
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.
âoeWho knew something as harmless as willful ignorance could end up having real consequences?â
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.
Do not look at laser with remaining good eye.
"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? ;-)
crazy dynamite monkey
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!
Who says the US has the right (or lack thereof) to put anything like this on the moon?
The "lack thereof" in brackets answers the main question. Whoever gets there and does it will have the "right" to go there and do it. I imagine the way we deal with completely unclaimed territory is still found under the "finders keepers losers weepers" clause of international law. I imagine something along the lines of an explorer planting his flag in the dirt and declaring "I claim this bit of rock for $sponsoring_country" which come to think of it the USA has already done on the moon.
I really doubt that you can focus a beam of microwaves with a reasonably-sized dish on the moon, and have it spread only to a couple square km over a distance of 100,000 Km. (That's about the right distance from Earth to Moon, isn't it?)
If only I hadn't slept through that explanation of diffraction all those years ago... Does anybody here actually know the math?
-Mark
As best I can recall them, the basic engineering variable traded off were:
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
Seastead this.
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.
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.
Because it's heaps easier to loft material, and in particular steel, from the moon than from Earth. You also get near-vacuum conditions for processing stuff and better solar conditions (although you'd have to bootstrap with a nuke until the moon mine had its own solar power satellite because of that 336-hour day). Moon mines would feed earth-orbiting powersats, which then feed antennae on earth.
The microwaves arrive highly dilute, so the splash is actually less than for power lines, and defocusses rapidly anyway if it loses tracking. Using 1960s technology, it was feasible to track aircraft in flight and power them with microwaves. Today, we could probably target them well enough to warm individual passengers' coffee.
Got time? Spend some of it coding or testing
It's kind of interesting to see how solar energy is considered some oddball tree-hugging thing when proposed on earth, but if it involves huge industrial and technological expenses and high-energy space lasers/masers, it is all of a sudden acceptable to a crowd of people that would otherwise don't give it a second look.
"isn't that higher than with traditional long distance wired transmission?
I seem to remember somewhere that only about 75% of power sent over long distance lines comes through......"
Sorry, properly designed 500kV and 1000kV lines are greater than 99% efficient.
Imagine the I2R losses at 75%.... 25% of 5000 AMPS at 500kV would make a LOT of heat.