Laser Power System Keeps UAVs Flying Indefinitely

Drone technology is driving the aerospace industry as companies trip over each other trying to develop the next big thing. Here’s a good example of what we’re talking about. Lasers can no be used to keep a UAV in the air indefinitely. The trick is to add an array of photovoltaic cells specifically tuned to an IR laser’s wavelength. A ground system then directs a high-intensity laser beam onto the aircraft’s cell array to transfer energy while in flight.

After the break you can catch a video from a trade show where a Lockheed Martin employee describes the successful testing of such a system. But there’s a lot more information available in the white paper (PDF) which Laser Motive has released. They’re the folks behind the technology who have teamed up with LM to implement the system. The laser unit on the ground can track a UAV visually, but there is also a method of using GPS coordinates to do so in the case of overcast skies.

[Thanks Bearmos]

60 thoughts on “Laser Power System Keeps UAVs Flying Indefinitely

    1. In that situation I would be more worried about the sudden loss of power to the UAV, but that is only in a condition where power distribution depends on the Laser and not stored power. I can just imagine so US military official going “oops there goes another 1.4 million dollars, hey you sciencey people go make me another” hehe!

      1. I’m sure it doesn’t directly power the UAV. It probably continuously charges internal batteries. Then when a laser is cutout it can still fly. You can use the power system just to re-charge your device. If they’re not already doing this I want the patent and a steak dinner, please!

      2. Obviously it is using an internal rechargeable battery. Powering it directly from the beam would be a major problem (atmosphere, weird objects that fly through the beam, precision of the directed beam, etc.) to the circuitry, and I’m sure that the beam won’t be able to aim at the PV-Cells 100% of the time which in turn would cause over voltage, or voltage drops.

        A good logic would be compared to “Aerial Refueling” if you’re familiar with that, and planes would obviously won’t run from the pumped fuel.

      3. Also, I forgot where I saw it, that NASA is doing the same concept for interstellar observers (which I thought was dumb, because in space SUNs are everywhere, and that using a PVcells alone is enough.)

      4. Chances are that its not like a normal “refuel”.

        Drive a car for 4-8 hours, and refuel in 2-4 minutes.

        Those big airplanes can fly for hours, and refuel in minutes (maybe tens of minutes?)

        So for a car the refuel-speed / fuel-use ratio is somewhere in the 60-200 range: You can refuel about 60 times faster than you spend the fuel.

        Here the “fuel use” is probably quite comparable to the amount they can beam up. So that ratio will be down in the 1.1 range. They can beam up about 10% more energy than is used in hoovering.

        That 10% is a wild guess. But beyond 2 would really really surprise me.

    1. Exact same questions here.

      Those the Watt values on sketch are the real ones??? becasue a 2000W Beam would be at way better use in the Weapon industry. And a 4000W generator on a truck would be not quite “non visible and silent”

      1. Even a 12kw generator is no big deal. My E450 diesel van has a PTO driven generator, which runs off the engine. I just put the truck in neutral, set the idle controller to 1200RPM, and its making 12-16kw for as long as she has fuel. 1200rpm is where the engine spends quite a bit of its time anyway, and its actually not that loud. It just sounds like a diesel engine humming along. Its a hell of a lot less noisy than the standard crappy hardware store generator most people know of.

      2. 2000W lasers are common in industry, a fab shop near me has a 2500W CO2 laser. It can cut through 16mm steel (focussed, the beam hitting the plane would be spread over a wide area).

        The 4000W input is wrong, that’s would mean 50% efficiency when 20% is good. A 10kW input would be more likely, 20kW believable. I do believe a ‘0’ got dropped off the end of that 4000.

        As @BadHaddy says generating that much power isn’t a challenge these days. Add on a few more kW for cooling and you’re good to go.

      3. Interesting paper, but they’re talking watts, not kilowatts.

        You’d need hundreds of those laser diodes.

        CO2 lasers are about 20% efficient (water-cooled glass tube), RF ones (air-cooled) are less.

        Still, the numbers they quote are within the realms of reality, though they don’t talk about the plane itself. Its solar cells are probably only grab 25% of the laser power.

    2. BadHaddy is right, ROFL i cant believe this

      PS: even if the laser is Infared, a simple cellphone camera is sensitive to IR. same with UV

      eventhough the/a camera has an IR filter, some still passes through. same with UV

      AND 1000 watts of power!!!!!

      assuming the posted diagram is correct? 1000w laser? reeeally?

      i mean you can see a 1w laser from 10 kilometers away, or more! a 1000w laser? it would make the news EVERY time you flew that “secret spy drone” and would be on youtube EVERY time as well

      i wouldnt want to be the one who forgot to cleanup a generator-fuel spill… falling burning pigioen

      PPS: even a 100w laser might burn a bird, but 1000w!
      EDIT: 2000w

  1. That’s also one way to paint a target on your plane. The enemy only needs a laser guided missile, we’ll track it or you.

    This might work well in a dry atmosphere, but I bet the power losses during humid weather would make it unusable.

  2. I thought I had heard of this tech before;
    Look under the “Aircraft propulsion” heading, I saw that when I first started researching about Quadrocopters. Interesting that Hackaday has only got hold of this now, thought it would have been old news by now!

  3. I recently saw a 400 size electric heli powered by a modified magnetron from a microwave. I will try to find the linkage to the video and will post it if I do. Very interesting stuff. The company I work for manufactures lasers for industrial use, and one of our machines was used two years ago for this very purpose as a test bed for space elevator applications. Two teams made it up the 1KM cable suspended by a helicopter, just not in the fifteen minute time limit to win the prize.

  4. I understand that it works. That there are times when long-term continuous aerial surveillance is more important than stealth, so it’s acceptable to have a big IR laser marker on your UAV. And since the UAV is operated in continuous line-of-sight to the ground station, any IR-seeking missile heading towards the UAV is conveniently visible from both UAV and ground; so both have the opportunity to detect threats. If a possible threat is detected, the laser can be temporarily shut off (or redirected at a cloud, chaff, mylar dummy target in tow, etc), and the UAV can take evasive action; all of which can be done automatically, and within microseconds.

    Still, it seems so brute-force.

      1. Ok, that’s only for recharging, but if you can build a tracking system for shooting down mosquitoes with a laser, then tracking an electric toothbrush in use shouldn’t be a problem.


        If you mounted a laser on your ceiling, it could detect, track and charge all of your portable devices whenever you have them out. Suck on that, induction charging! Quick, to the patent office!

      1. Yes, yes, we’re all heard of Tesla.

        Yes, yes, we’ve all seen the pictures of the towers etc.

        Yes, yes, we know you can light up fluorescent tube with it.

        Yes, yes, the smarter ones amongst us know it didn’t work all that well.

        Hubbard should have included Tesla into Scientology somewhere, though at this rate the fanboys will be starting up their own religion soon.

      2. Yeah… and you can already power a fluorescent tube with no wire and for free… go under a high power line and that will work…
        The only problem is that it’s just like being in a microwave… your body don’t really like that kind of energy going through it…

  5. I’m not sure we see this in the field much, but if you do, it’s nice that UAV’s are clearly lit up on any camera then, including those in AA missiles.

    And of course hackers can make a tracking camera based on itand then add a rifle to it to keep their skies clean of the damn things.

    1. There have been a few solar planes. Unless they’re extremely well made, the panels don’t generate enough electricity to let the plane run indefinitely (even in constant cloudless weather). Using a laser allows them to send a lot more energy, fully recharging the batteries. It would be nice for extended airtime though.

      1. In order to get enough solar power to stay airborne and carry a useful payload, an airplane must be very large and lightweight (therefore delicate). A laser receiver can be very small, so can go on a small, rugged aircraft. Smaller also means cheaper, so it’s not such a big deal if/when it crashes.

        Lasers might not be the answer to every problem, but they might be applicable in this situation.

  6. Laser powered UAV…

    How about something of use much closer to home like a hat with laser turrets that blast insects that come near the wearer’s head, especially around ears and face?

  7. IR energy can cook the skin very easily. Since the naked eye can’t see it, you won’t blink till it’s too late. What about those other aircraft that happen to fly through the beam?

    I don’t know or any CCD with passiveIR filters that would take that kind of direct energy. I would guess that IR sensitive objects would go blind too.

    Remember that staring at a 1000w halogen bulb is not the same thing as a 1000W IR laser.

    With the halogen bulb you may get flash blindness or temporary eye pain. With the laser I think your eyes would boil and pop. The intensity of the laser is so much more. If you compared the intensity per sq cm, you would find the the laser would blow the halogen bulb away.

    That is why lasers are so dangerous. You can’t really cut wood with a 100w light bulb very well, but put that power into a laser and watch out.

  8. So circa 1991 after 3 days in the wilderness I headed South and wound up near Area 51 in Rachel Nevada at the Little A’Le’Inn to get a burger, and I also bought an intriguing book called Sport Death: A Computer Age Odyssey, by Robin Heid © 1987 LCCN: 87-71502 ISBN: 0-9618830-0-6 Change Agent Press which is the first book of a planned trilogy according to the author, but I never found anything else by him.

    What’s so interesting about this book aside from the typical melodrama/space age adventure plot, is the main aircraft in the story looks like the mythical Aurora hypersonic space plane, so called successor to the SR-71, and besides being “unmanned” and piloted by an advanced computer “entity”, it has a large Sapphire “window” on the belly to intercept a ground based LASER pulse to give it the boost needed to achieve hypersonic speeds, therefore saving on the weight of fuel & tanks etc., and aside from the intelligent agent pilot, it really sounded feasible.

    If this technology relies on occasional short pulses of a high power LASER like in the book, than depending on the wavelength used, the likelihood of the beam being spotted isn’t as great as the doubters here have maintained. And I wouldn’t be surprised at all if this was already operational in the “black world”.

    1. The idea has been kicking around for a while.

      1985 – In ‘Footfall’ (Niven & Pournelle) you’ve got rockets powered by ground-based lasers. People have made small scale versions.

      Even earlier (1974) their ‘motie’ series has solar sails boosted by lasers.

    2. Pulsed lasers are better for vaporizing a reaction mass, causing the aerial vehicle to thrust away from the ground-based laser. Good for rockets, or possibly a departing plane; but no good for a surveillance UAV that’s circling an area.

      In this case, the UAV is converting the laser energy to electrical. Efficiently transmitting and receiving pulses that are short/infrequent enough to be stealthy, would be much more difficult than CW.

  9. The UAV drones are basically used to minimize the working personal. Yes you are right a UAV drone can be used 24*7. They need only a tank full of oil to fly. Now a days they are equipped with different type attacking instruments to attack the enemy. A UAV drone can enter an area where most military personals can’t entered.

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