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NASA Flies First Laser-powered Aircraft
unassimilatible writes "NASA has successfully tested a small-scale aircraft that flies solely by means of propulsive power delivered by an invisible, ground-based laser. How far away can in-flight IP/LASER broadband be?"
How far off can space death rays be is the real question
or something like it:
It used microwaves instead of "invisible lasers" (IR? i havent RTFA yet) but same end result, no?
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One of the hallmarks of classic science fiction, Larry Niven & Jerry Pournelles' "The Mote In Gods Eye", proposes this very thing. The opening sections of the book are based upon on premise: lacking true FTL travel, an alien race reaches a human colony by building humungous lasers in their asteroid belt and planet surface, and using them to propel a light sail armed interstellar craft between stars. Good book all around, and it's cool to see decent Science Fiction become more than just speculative drivel (it's one of my favourite books).
This is the technology they want to use to power the space elevator.
If they are using laser beams to power a generator in the plane, why don't they use this to solve our energy distribution problem? In blackouts, just beam power to cities by laser.
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How far away can in-flight IP/LASER broadband be?
Let's hope it's very, very far off. A laser beam pointing to/from a commercial aircraft is essentially a giant pointer, constantly updated, announcing the precise position of the plane. It should not be difficult at all to build a guidance system that follows the laser and delivers a payload to the plane just as a line climber follows a kite string to a kite. Said payload is not likely to be an emergency delivery of peanuts and soda.
Now, did I say they used the same principle? Thanks, I did RTFA. :-)
Laser driven Space Sails (ok not solar in this case, but light-driven, although they would prob use solar as well) use the momentum of the photons to push the craft forward - but you still need a damn powerful laser to do it effectively..
Laser driven space sails are one of the few feasable technologies we really have that could be used for sending probes interstellar distances in a viable time-scale.
The 2 concepts have the same sort of principle idea - if you dont have to carry fuel, a craft can keep aloft/accelerating for very long periods of time..
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They directed a laser beam at photaic cells? Nice other name than solar panel. OK, the laser powered plain flies as long a laser hits it. But still the plain is carrying it fuel (photaic cell aka solar panel) on board, as meantion in the introduction. This is no breakthrough but rather a toy for big children.
I can see it now:
"Homeless celebrate as pre-cooked pigeons fall from sky near airport"
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Well least missles won't need their own guidance now . They can just follow the laser.
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The atmosphere is an ocean, you can float on it effortlessly. Why spend so much time trying to expend energy to stay up?
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Hmmm, a system capable of tracking the precise position of an aircraft? You mean like RADAR?
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"They do not preach that their god will rouse them, a little before the Nuts work loose." Kipling, 'The Sons of Martha'
When was the last time you saw an invisible laser.. lasers are in the visible light spectrum
I'm not a physicist, but I've seen lots of inivisble lasers (okay, not the beam itself, but you know...). Lasers in both the infrared and ultraviolet regions are commonplace. Google for "infrared laser" or "ultraviolet laser" and you'll find many, many examples of each.
I suppose you could make some sort of argument that the L in LASER if for "light," and that IR and UV somehow aren't light because we can't see them. But insects and perhaps some animals can see in those regions, so it'd be a difficult position to defend. Both IR and UV are called "light" in general use. Additionally, there's no significant physical difference between a visible light laser and a UV or IR laser. And scientists now use the term "laser" even where most people would agree that the electromagnetic energy in question falls outside the part of the spectrum that we tend to think of as "light," e.g. x-ray lasers and microwave lasers.
I first read about this sort of thing back in the 1970s. Proposals back then focused on constructing huge satellites (think 5 miles by 5 miles or 10 KM by 10 KM) in geosynchronous orbit. Energy would be beamed to earth via microwaves or lasers.
Planes could be powered via laser pointed at various reception devices (photovoltaic, steam generators, etc.).
Clouds would not be a major problem. Just pick a frequency that penetrated the clouds fairly easily. Or, in the case of airplanes, fly above the clouds.
For lots more information, just Google "Space Solar Power".
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It'd be nice if I could something like this to work to power my laptop!
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This is cool but I like China's space program better...they are going to be doing manned exploration of S P A C E.
National Aeronautics and Space Administration
Who do you get to be an expert to tell you something's not obvious? The least insightful person you can find? -J Roberts
So, what happens when it gets cloudy?
Or something else that vexes me even more greatly; will it be able to fly in london? (fog).
GAAH! MY PRINTER IS ON FIRE!!! PUT IT OUT! PUT IT OUT!
I saw it on a PBS show about advanced propulsion devices a few years ago. Very much a research project, and not currently capable of carrying a payload, but interesting for its simplicity (in the craft at least).
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Here is a different solution (from back in '99) using a conical mirror to focus a high-powered laser and ignite the air underneath it to generate propulsion. Perhaps not generally useful yet, but perhaps more generally applicable than charging solar-cells with a laser.
National Aeronautics and Space Administration
If they just explored space they'd be the NSA... OH HEY! I think I've stumpled onto something!
I'll be right back.. I hear a knock at the door.
Ever since the dawn of powered flight, it has been necessary for all aircraft to carry onboard fuel - whether in the form of batteries, fuel, solar cells, or even a human "engine" - in order to stay aloft.
But a team of researchers from NASA......is trying to change that
But how does it work Bob:
The laser tracks the aircraft in flight, directing its energy beam at specially designed photovoltaic cells carried onboard to power the plane's propeller.
Now how do 'solar cells' count as fuel when 'photovoltaic cells' don't?
M0571y H@rml355.
One of the major problems with moving anything from place to place is getting energy to move it. That energy typically comes from partial conversion of matter (liquid oxygen, gasoline, coal, hay, etc.), and that matter in turn tends to be carried along with whatever you're moving. That matter in turn needs energy to move it, and in some cases this amounts to a rather offensive amount of overhead (e.g., Saturn V).
There are two ways of handling this. One is to get the most efficient conversion possible, to cut down on the amount of mass needed. The other is to figure out a way to use whatever matter is in the area, so you don't have to bring it along. It's like bringing along a credit card to buy food when you get to Peoria, instead of bringing a bunch of food in your luggage.
A variation is to deliver that energy in some lightweight form, such as photons. Even if the system for generating this energy is huge and weighty, it can just sit on the ground and not move, which is the most important thing.
Far in the future, it may be possible to move objects weighing several hundred pounds this way, at a range of several miles. Specifically, a family and their luggage. They could zip around at 3000 meters up, powered by laser repeater stations every few miles, set up much like cellular phone towers, except perhaps in special air lanes analogous to interstate highways. This would save billions of dollars in fuel that would otherwise have to be moved around along with the important cargo.
Eventually, one might also see goods transported to space this way. As was said earlier, a space elevator could use this to move cars up and down.
Lately democracy seems to be based on the skybox, the Happy Meal box, the X-box, and the idiot box.
Well, if it is invisible, by definition I could not see it...
lasers are in the visible light spectrum
I have an Associate's Degree in Laser Electro-Optic Technology. Any oscillator that produces electromagnetic radiation in the range of infrared or shorter wavelengths by the process of stimulated emission of radiation is considered a laser. In fact, the name has become shorthand for just about anything that produces a beam of anything through quantum triggering (e.g., an "atom laser"). A carbon dioxide laser's primary (strongest) output wavelength is 1.6 microns, which is well within the infrared portion of the spectrum, and completely invisible to the human eye. The Nd:YAG laser also produces its primary wavelength in the infrared range (the beam is often sent through a frequency doubling crystal, which produces green light at half the power of the input beam). CD players use an infrared diode laser (invisible beam). At the other side of the visible spectrum, the eximer laser produces ultraviolet light, at a wavelength that is invisible to the normal human eye. The nitrogen laser also produces a beam that is not directly visible to the unaided human eye, but the beam causes air to fluoresce in a wavelength normally visible to humans.
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