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X-37b space plane’s microwave power beam experiment
- jarym 7y agoAnyone know what impact this will have on anything that gets in the way of these high-energy microwaves? I’m thinking birds or manned aircraft?
- mckirk 7y agoI imagine it would depend greatly on whether the beam was set to 'Max' or 'Defrost'.
- PopeDotNinja 7y agoI'm imagining a hacker pointing a bunch of microwaves beams at all the corn fields to heat them up, causing the Popcorn Famine Of 2052.
- hnhg 7y agoI don't know if you're referencing it but that was the ending of Real Genius: https://www.youtube.com/watch?v=rthHSISkM7A https://www.youtube.com/watch?v=rthHSISkM7A [edit: possibly a spoiler?]
- qubex 7y agoThat’s exactly the scene I thought of but the last time I saw that film I was 11 in 1992 and I had no idea what the title was! Thank you!
- PopeDotNinja 7y agoI had completely forgotten about that awesome seen. Thanks for the reminder!
- fpoling 7y agoAccording to Wikipedia the power density of various proposal to beam energy from space should be harmless for human. https://en.m.wikipedia.org/wiki/Space-based_solar_power https://en.m.wikipedia.org/wiki/Space-based_solar_power
- ben_w 7y agoAt those intensities, microwaves seem significantly less useful than optical PV.
- m4rtink 7y agoWell, they work at night if your solar power satellite is high enough (eq. GEO).
- ben_w 7y agoThe same applies if the beaming is done with an optical laser instead of a microwave.
- m4rtink 7y agoSure, that's true - I guess microwaves still could have some benefits, for attenuation in the atmosphere/weather maybe ?
- fpoling 7y agoOptical laser is rather inefficient at converting electricity into optical energy. Surely there are some low-powered diodes where one can get over 50%, but for powerful lasers efficiency like 1% is a good number. Consumer microwave ovens on the other hand has efficiency like 65%.
- zajio1am 7y agoMicrowave rectenna is more efficient than optical PV. Also, microwave is less affected by weather than visible light. As a power source, they also can have much higher capacity factor than PV.
- fabianmg 7y agoIt sounds like a test for a future space weapon. Something that, anyone correct me if I'm wrong, it's banned right now. They sell it as a new energy source and that way they circumvent the ban.
- avar 7y agoYou are wrong. The Outer Space Treaty bans nuclear weapons in space, but e.g. mass drivers shooting tungsten slugs which would have nuclear-like effects aren't banned, nor is anything else. Even if a treaty did ban these weapons it wouldn't be "illegal" for a major power in any meaningful sense. These mutual arms restriction treaties are only followed by the major power as long as they see a mutual interest in doing so.
- jabiko 7y ago> These mutual arms restriction treaties are only followed by the major power as long as they see a mutual interest in doing so. Sorry, but this really rubs me the wrong way. The whole reason we have these kind of treaties is to protect nations which don't have the power to defend their interests should a conflict arise. Saying that it is normal for a nation to just ignore a treaty they have ratified IMHO instills a very wrong mindset. If a nation ignores a treaty, the reaction should not be "Oh, that was to be expected".
- forgot_again 7y agoThe powerful have control and the weak unfortunately have to sit by and hope the powerful live up to their word. Without external forces (a higher authority or some sort of coalition of the weak) to check the impulses of the strong, the strong get to make and break the rules as they please. This is inevitable and a fundamental fact of reality.
- credit_guy 7y ago> If a nation ignores a treaty, the reaction should not be "Oh, that was to be expected". A nation can withdraw from a treaty instead of ignoring it. The US just withdrew from the INF treaty. In retaliation, Russia withdrew too (they were the only signatories). In 1936 Japan withdrew from the Washington Naval Treaty and built the formidable battleship Yamato (armed with 18 inch guns, by far the largest in WW2). What was the world supposed to do? The US imposed various sanctions on Japan. At some point the sanctions became so hard that they amounted to an economic death sentence. WW2 was not averted. The unpleasant truth is that international treaties are not worth a whole lot. For the simple reason that there's no international equivalent of law enforcement.
- dayofthedaleks 7y agoA global network of satellites beaming power to insect-sized drones near the ground? Splendid.
- teruakohatu 7y agoRemember simcity's microwave power station? Microwaves beamed down from space :)
- masnao 7y ago"it's all fun and games until somebody lose an eye" in city telecom microwave antennas on top of buildings already kill thousands of bird every day. maintenance checklist start with "clean the dead birds from base of antenna"
- dayofthedaleks 7y agoI don’t believe the frequencies used for terrestrial communications cause injury, but rather birds are generally killed by physical impact with towers. Much like windmills. Please show a source if I’m mistaken.
- rumanator 7y agoApparently birds colliding into towers is a thing. https://en.m.wikipedia.org/wiki/Towerkill https://en.m.wikipedia.org/wiki/Towerkill TIL.
- sarbaz 7y agoThe problem is that directly in front of a microwave antenna, power output is on the KW order of magnitude. This is like standing in front of a microwave oven with the door open - in a few seconds you will have severe burns.
- masnao 7y agoI can point out you're mistaken simply by saying "frequency". it's power that kills. you can make a death ray with light, vhf, whatever, given enough power, which decay geometrically. most of the dead birds are on antennas without cover, where the birds would perch up and get fried. thousands of dead birds every day on top of builds is the sole reason all microwave antennas have that white half-cone cover on them.
- imglorp 7y ago24/7 availability was mentioned several times. Does this mean it's possible to have a satellite in geostationary orbit that is never eclipsed by the Earth? Or does it mean you have more than one satellite serving a power receiver?
- DFHippie 7y agoThe latter. This is discussed later in the article.
- m4rtink 7y agoGEO satellites are pretty much always in the sun, minus couple hours per year when they hit the (very snall at this altitude) Earth shadow.
- 4gotunameagain 7y agoGEO orbit is too high for this application, since it would require an insanely collimated microwave beam (or insanely directional). The power loss is proportional to r^2. Google "spherical spreading loss"
- DennisP 7y agoThat actually is doable. GEO is generally considered the best orbit for a solar power sat. The receiver has to be several kilometers across, but that's good because you don't actually want to fry any birds flying through. There have even been proposals to put transmitters on the Moon, but that's stretching things.
- 4gotunameagain 7y agoSure, but I thought the consideration here was about UAVs and the such :)
- iso947 7y agoYou can have orbits that are never eclipsed by the earth, but not GEO. GEO satellites go dark for about an hour a night for about 6 weeks a year. https://www.stephenmack.space/blog/geostationary-satellite-eclipse https://www.stephenmack.space/blog/geostationary-satellite-e... Contains a video of them
- dirtyid 7y ago>In addition, it could allow satellites to provide reliable power anywhere on the planet or even to spacecraft or other satellites in orbit. Aka laser ASAT platform. Seems like one of those read between the lines Space Force press releases. References to laser beam UAV kills, original research by Revolutionary Munitions Directorate etc. All the remote power through atmosphere interference sounds pretty fanciful TBH, whereas crippling adversary satellites using beam energy instead of kinetic impactors (=space debris) seems like the most parsimonious application.
- SiempreViernes 7y agoIt would be in line with the tradition of using "ballistic missile defence" as a pretext for developing ASAT capability. I would question if there really is such a strong push for even more US ASAT tools in the USSF, though given the current administration I guess the "kill 'em all" mentality has a good wind in their sails.
- dirtyid 7y agoMy understanding is there's a much greater emphasis on counter-space capabilities now that US military is shifting towards peer to peer confrontations (China). ASAT... especially a concurrent global network is going to be pretty key to nullifying the Chinese missile gap in SCS by disrupting the killchain - Chinese satellites - in a manner that doesn't endanger US space assets. Also this was a month ago: https://www.space.com/russia-anti-satellite-missile-test-2020.html https://www.space.com/russia-anti-satellite-missile-test-202... Beyond just needing the capability, media releases like this seems to be oblique posturing as well. Edit: apparently posting to fast? Reply to below: >ASAT warfare is hugely advantageous to them Most threat models anticipate disrupting space assets in peer to peer conflicts to mitigate technological edge. All the old ASAT tests have been missiles that create debris (or potential debris in deliberate near misses), Recipe for kessler syndrome if executed at scale. So moving to beam ASAT that can disrupt / destroy sensors precisely without adversely risking the space commons might not be a terrible development in terms of space arms race. Also if memory serves some of the new Chinese satellite used to track SCS shipping (US aircraft carriers) are in a high orbit that can't be hit by current ASAT at all. So this might be developing new capabilities. It certainly makes sense to hit other objects in space vacuum at speed of light than to power drones through clouds.
- hawski 7y agoThis would also have a great application for commercial flights. It would be also a bit easier if energy would be sent only above clouds.
- choeger 7y agoThe practicality rests on two open questions, I guess: 1. How much power could a satellite generate, realistically? 2. How many targets could it serve simultaneously? I imagine there is a huge difference between being able to support a single, ultra lightweight drone and, say, hundreds of reapers.
- m4rtink 7y ago1) Sun output minus conversion loses. Also you likely want nore than one, eq. a Dyson Swarm.
- 4gotunameagain 7y ago"Sun output" at reasonable Earth orbits for this application is maximum ~1368 W/m2, and that only when the the panels are perpendicular to the direction of the rays. What is considered a "reasonable" orbit depends on our ability to collimate the microwave beam's rays, which is not an easy task
- pjc50 7y agoThose questions are determined by how many solar panels and transmitters you have on the satellite? For comparison, the ISS generates 240kW when in sunlight. So for the 7MW mentioned upthread to power an airliner (or half a Eurostar train), you need something 28 times larger than the ISS.
- MayeulC 7y agoWhat would it take to power an airliner? Wireless power transmission would be ideal for a lot of applications, transportation (electric cars, planes, maybe trains, UAVs, boats) chief among them. You could shave a lot of weight out of an electric plane by reducing its battery capacity to an emergency supply. This would also greatly reduce the carbon impact of flight transportation, while making a case for bootstraping a beamed power constellation and ecosystem. I guess that's something Nikola Tesla first envisioned :) Unfortunately, from what I know, microwaves are not really harmless, unless diffused over a large area, and you then need a large collector. An airliner could do, if big enough. I don't know either if a beam can be steered fast enough, and what would the economics behind be.
- Someone 7y agohttp://large.stanford.edu/courses/2013/ph240/eller1/ http://large.stanford.edu/courses/2013/ph240/eller1/: “The power required to keep a Boeing 737-300 flying at a constant altitude and speed is 7.2 × 10⁶ watts.” So, ballpark 7 MegaWatts, more during ascent, and add a bit if passengers want to watch movies, eat hot meals, drink soft drinks, etc. On the plus side, if the airplane doesn’t have to carry fuel, carrying capacity could go up (with some redesign to make the plane strong enough to land fully loaded), so that 737 might be equivalent to a 747. That 737-300 has about 125m² of wing area, and, guessing, about the same are for the body, so that would be 7MW/250m² = 28kW/m². The sun delivers about 1,400W/m², so that’s 20 times what the suns delivers on a cloudless day. Now, most of the time, the ground station (or solar space array) beaming the energy wouldn’t be directly below/above the plane, so the required power/m² could go up a lot ⇒ I would make sure that any windows in the plane wouldn’t let the microwaves through. Doable? Possibly, but on ground level, I guess it would be wise to use a lot more area for sending that amount of power up, to prevent killing birds.
- deleted 7y ago[deleted]
- johndough 7y agoI don't know if you could kill birds with this, considering that the beam would move at something like 250 m/s during regular flight. Is microwave radiation more deadly than solar radiation? Might be a problem at the base station, but there should be multiple of those for greater fault tolerance anyway.
- aaron695 7y agoLol, we are going to spend billions to possibly send down the power of a few litres of fuel to a drone a day? Maybe targeted at someones head it might pay for itself, but still pretty sci-fi if it was possible. Just send from a blimp. Or send the power up to the satellite to power them, it's good as free from the ground, if this stuff is possible. [edit] I would have ruled out this being a ruse to confuse people from the military's side, since it's so crazy no one would believe solar panels in space transmitting energy to earth was possible. But maybe not it seems..... I assume IRL it's for communications, or jamming, shooting a missile out of the air?
- dr_dshiv 7y ago> Just send from a blimp. Drone Mothership
- throwaway888abc 7y agoSeems great technology. Hope they also address any impact on ecosystem.
- JoeAltmaier 7y agoI wonder how they don't fall afoul of Tesla's patents? https://www.damninteresting.com/teslas-tower-of-power/ https://www.damninteresting.com/teslas-tower-of-power/
- detritus 7y agoPossibly something to do with his having been dead for nearly 80 years?
- JoeAltmaier 7y agoSomebody owns those patents...
- Scarblac 7y agoPatents are only valid for 15 years or so.
- willis936 7y agoThat’s the idea. I have no clue what’s going on with big companies sitting on stacks of tens of thousands of patents and litigating people for violating patents unrelated to what the company produces.
- JoeAltmaier 7y agoAh yes, when he filed the limit was 17 years. I had some notion they could be renewed. I guess I was thinking of copyright.
- dangerbird2 7y agopatents expire after 20 years
- progre 7y agoPatents expire. That's the point of patents. Instead of complete secrecy thats practically impossible to maintain we have a system where patented inventions are publicly disclosed and the inventor gets to have sole use of the invention for a limited time.
- martinaoe2 7y agoanyone know what the conversion and transmission power loss is?
- Tade0 7y ago“If we had a way to keep those drones and UAVs flying indefinitely, that would have really far-reaching implications. With power beaming, we have a path toward being able to do that.” Why go through all this trouble when there's this? https://www.amprius.com/amprius-silicon-nanowire-lithium-ion-batteries-power-airbus-zephyr-s-haps-solar-aircraft/ https://www.amprius.com/amprius-silicon-nanowire-lithium-ion... While 25 days is the record, I'm sure this thing can remain aloft for at least a week at a time. To me the solution from the article appears expensive and suspiciously deathray-ish.
- varjag 7y agoBecause it's a superlight UAV without any instrument package or ordnance load.
- Tade0 7y agoI see no indication that anything heavier could be powered via the method described in the article.
- varjag 7y agoThe beam is on the order of kilowatts. Noone is going to deploy satellite network just to power some semi-gliders.
- Tade0 7y agoBut how efficiently can the drones receive such a beam? I checked and the Zephyr S has a 5kg payload - not much, but enough for instrumentation. And they're making an even bigger one.
- ChrisMarshallNY 7y agoWasn't Tesla consumed with beamed power? I seem to remember that was what Wardenclyffe was about. https://en.wikipedia.org/wiki/Wardenclyffe_Tower https://en.wikipedia.org/wiki/Wardenclyffe_Tower I remember reading a Repairman Jack novel about it. I think it was Conspiracies.
- king07828 7y agoElon Musk giving shade to space based power "You'd have to convert photon to electron to photon back to electron. What's the conversion rate?" [1] https://www.popularmechanics.com/technology/a8101/elon-musk-on-spacex-tesla-and-why-space-solar-power-must-die-13386162/ https://www.popularmechanics.com/technology/a8101/elon-musk-...
- andbberger 7y agowho cares?
- h2odragon 7y agoAFAIK (which isnt far) he was always talking about using ground wave transmission, too; which no one else had any idea how that was supposed to work, then til now.
- mhh__ 7y ago> no one else What makes you think he did?
- henearkr 7y agoTHIS was the missing tech to start launching iteratively what will become a Dyson's sphere. The step zero could also be using Earth's deserts. And then step one is using a space shell of satellites. Because the available surface at a large distance of Earth is huge, even considering the constraints of not creating too much shadow for life's photosynthesis. Further in the future could be step two, some flotilla at Lagrange points or even directly in a solar orbital between Earth and Mars (so that this will never create any shadows to us).
- fit2rule 7y agoI mean, this could happen: we deploy a microwave energy station above the Sahara, and build that space tower ...
- henearkr 7y agoIn my idea, the energy production would be the solar-panel-satellites. Or the deserts if we are only at step 0. But for drones and other energy-receiving devices, imho the ground grid and batteries are still the best option, as the wireless powerlinks towards the ground should be reserved to where it cannot be avoided. Any smaller powerlinks from-space-towards-space would be fine though.
- andbberger 7y agoYou know, deserts aren't empty.
- willis936 7y agoTakeoff and ascension use the most power. What happens when it’s foggy and cloudy? Do you have to wait it out? Planes cannot afford the weight of large batteries.
- Fotograf 7y agoI ask the same. And the solution does not seem so far out that we should not be able to achieve it without these half assed solutions. But that is just my opinion https://fotografnu.dk https://fotografnu.dk
- mrfusion 7y agoSo what’s actually new here? Why can’t we test this same system on earth? Is it a laser or a focused microwave beam? Will it hurt if a bird or airplane flies through the beam?
- tren-hard 7y agoThey did test it on Earth, there's a bunch of examples in the article, but you are limited to line of sight on Earth.
- DennisP 7y agoA couple years ago I read a book[1] on space solar power. It was written before SpaceX really got going, and estimated a cost of 15 cents/kWh for a gigawatt-size solar power satellite in GEO. Old designs from the 1970s were monolithic beasts, and would be horribly expensive even if launch were free. The new designs use a large number of small identical components (of seven or eight types), which self-assemble in orbit. That way you can mass-produce them. I plugged SpaceX Starship launch costs into the book's estimate and got a total system cost of 5 cents/kWh, which is pretty good for steady clean power that doesn't need storage. [1] The Case for Space Solar Power by John Mankins
- sandworm101 7y agoFor space-based solar to be efficient, ie for it to be better than just installing normal solar panels, the beamed energy would have to be at least as powerful as sunlight (1000watts per square meter). That is a very very high bar to overcome. Compared to the simplicity of solar+batteries, I don't see a future for beaming solar energy down from space. Maybe once every square meter of roof space has been dedicated to solar panels, once every city is essentially blanketed in panels, then it may be time to turn to space for more energy. One might say that space-based solar would operate 24/7 and so is better than normal solar panels. That's isn't reality. Low-orbit satellites spend half their day in darkness too. To hit a receiver on the night side of earth a satellite would have to be at a very high orbit, reducing beam efficiency and increasing launch costs.
- evgen 7y agoLow orbit sats spend far less than half the day in darkness; it is only when they are in the penumbra of the earth that they are in darkness. What makes space-based power interesting is that such sats have a line to sunlight (and therefore power) when a portion of the planet below them does not, enabling them to provide power for a period of time after sunset and also before sunrise.
- deleted 7y ago[deleted]
- dghughes 7y agoThe power must be enormous at the source. It would degrade considerably from the source, inverse square law.
- Turing_Machine 7y agoThe inverse square law only applies to a point source radiating uniformly in all directions. Laser and microwave beams, while they do suffer from losses over distance, aren't anywhere near that bad.
- cevans01 7y agoThe inverse square law still applies to directional transmitters and optical transmitters. It's just that their transmit gain is much much higher.
- blackaspen 7y agoMy first reaction to this was Sim City 2000's Microwave Power Plant (and the occasional miss of the microwave beam): https://simcity.fandom.com/wiki/Microwave_(disaster) https://simcity.fandom.com/wiki/Microwave_(disaster)
- numtel 7y agoIn SimCity 3000, the Microwave Power Plant is also first available in the year 2020. Coincidence? I think not :)
- stcredzero 7y agoCarrying one's power supply onboard a rocket in space and even on an airplane is a huge weight penalty. What if high energy density beams could power a substantial VASIMR thruster? That would make for awesome LEO to GEO orbital tugs. It would also be a good basis for a drone "space fighter" that could reduce the rocket equation penalty through ultra high ISP. Reliable high density power beaming could enable fully automated cargo drone aircraft. These would have fundamental advantages in operations costs due to weight savings, the simplicity of electric motors, and reduced personnel costs. If we could generate large amounts of power in space and use sufficiently large transmitters (re: diffraction limits) to beam it to VASIMR thruster spacecraft, we could substantially reduce transit times to Mars, as one example. Alternatively, we could also greatly increase mass fractions of cargo delivery to Mars.
- qwertox 7y agoIf one assumes that the beam feeding the drone is not a cylinder, but more of a cone with a Gaussian profile, then technology could get built which detects the source and the target of the beam. So no matter how much you stealth the drone, you'd have to deal with that new problem.
- blendo 7y agoI was surprised to learn the rectenna was invented as recently as the 1960s: https://en.m.wikipedia.org/wiki/Rectenna https://en.m.wikipedia.org/wiki/Rectenna And in 2015, the optical rectenna: https://www.me.gatech.edu/featured_colarectenna https://www.me.gatech.edu/featured_colarectenna
- passerby1 7y agoCan the effect of capturing and sending more enegry to Earth from space (than Sun does now) be compared to global warming effects from currently burning fossils?
- andbberger 7y agoYou can position the solar panels to shade the earth which wouldn't change the total impinging power.