Solar Powered UAV to Set Aviation Endurance Record? 59
Iddo Genuth writes to mention that a group of Israeli students is hoping their latest unmanned aerial vehicle (UAV) will soon break the world aviation record for endurance that has stood for over 17 years. The piece features a short history of solar power aviation and an interview with the students.
hmm (Score:2, Insightful)
I dont really see this being applied to commercial passenger or cargo planes. Maybe ultralites.
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This doesn't have to replace traditional fuels, it can supplement them.
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When they pull a plane to the gate, they hook it up to a power system to keep the AC, lights, etc, running, without wasting fuel. How much could be saved both fuel and electricity at the airports?
Why don't you just put solar panels on the terminal roof then? Cheaper, no weight added to aircraft, easier to engineer, and useful when the plane's not there.
Solar power for airplanes is a niche market - high, slow, endurance, light weight. You won't be seeing it on airliners anytime soon.
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This doesn't have to replace traditional fuels, it can supplement them.
While technically not impossible, it would be completely impractical.
Solar's strength is high and slow. High, because you're actually going to get more sunlight (power) as you climb, whereas combustion engines lose power as you climb due to thinning air. (One reason why Helios was pushing 100,000 feet.) Slow, because you're using an electric motor to turn a big, slow revving prop. (Props can't get anywhere close to mach without tre
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The added maintenance costs are a problem. But the price depends on the expected life of the cells; flex is not so much an issue, since a grid of smaller cells can be used that will allow flexion of the wing. I'd expect debris to be a bigger factor, really reducing efficiency in the long run. As for weight, I'd expect the cells to be fairly light; fuel, on the other hand, is quite dense. I
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Again, why can't you run your engines off jet fuel, and everything else (lights, radio, etc) from solar cells? Save some fuel in the process.
Same reason you don't have solar cells on your gasoline powered car powering your electrical system - because its waaayyyy cheaper to just let the engine turn a generator. Airliners also fly during the evening, at night, and at high latitudes where the sun's angle incidence is too low for the solar panel to produce meaningful power.
Airships? (Score:1)
Solar's niche is high altitude, slow speed and long endurance. It will have some neat uses, but there's not enough oomph for high speed or high payload applications like jetting to Vegas for the weekend.
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today ultralites, tomorrow something else. i'm no avionics/aviation specialist, but come on. real advances happen when people think outside of the box. typically, "the box" just means "what was previously thought impossible."
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Longer-lasting spy-plane surveillance missions or even explosive carrying missions would probably not be something the Israeli Military would be adverse to. Unmanned probes that can reach not just Beirut but Tehran, and stay up for days waiting for the target? It's a sure seller, and the rich uncle Sam will as always pay for the new toys.
Hurray to the advanced societies! (Score:3, Interesting)
A modern "Western" society (including Israel) is too advanced socially and culturally to deal with the inconvenient people the old-fashioned way — through massive killings, destruction, and/or religious conversions (the latter being the mildest form).
While undoubtedly a good thing, this inability is seen by some as da
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Break the world record... (Score:2)
For a small solar radio controlled flight:
That's a long way for a small aircraft, but a full-sized on
Well that was fast (Score:2)
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The server runs on solar power. Unfortunately it's cloudy and their reserve ran out w/all the Slashdot traffic.
UAVs? Long range? Oh dear! (Score:4, Funny)
-- Secretary of State Colin Powell in a presentation before the U.N. Security Council, February 5, 2003
Oh, snap! These are just students trying to set a new endurance record. The purity and essence of our natural... fluids are not at risk. Surely we must issue the recall code immediately.
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If you can make a UAV that climbs to ~100000 feet in the day and glides down slowly enough that it's still above ~50000 feet at dawn, then you'll avoid all weather (including clouds) except on takeoff and landing. I could see something like that staying up for months or years at a time.
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Low-cost Satellites (Score:4, Interesting)
"Called the Zephyr, it's an aircraft that can fly continuously using nothing but solar power and "low drag aerodynamics". The combination of solar panels on the upper wing surface and rechargeable batteries allows Zephyr to be flown for many weeks and even months. The first flight trial of the Zephyr were conducted recently by QinetiQ in White Sands Missile Range, New Mexico.
Two aircraft were flown for four and a half and six hours respectively, the maximum flight times permitted under range restrictions. The maximum altitude attained was 27,000 feet above sea level. The ultra-light aircraft is designed to fly at altitudes as high as 132,000 feet (25 miles/40km), above normal commercial air-lanes and most weather.
QinetiQ believes that stratospheric platforms will rapidly become commercially viable and revolutionize future communications. High altitude platforms of this sort could provide a cheaper alternative to satellites in remote areas and developing countries. They can also enable observation of natural disasters and humanitarian crises."
http://www.treehugger.com/files/2006/03/solar_pow
Re:Low-cost Satellites (Score:5, Informative)
1. Antenna aiming isolation. The same downlink frequency can be shared by many more users since the downlink antennas could be directional enough (like satellite dishes are) to reject other sources. This is true of geostationary orbit satellites, but the locations can only really be varied along an arc over the equator. Aeronautical platforms can be moved in two dimensions (obviously they really are in 3 dimensions, but the antenna aiming will still simply be azimuth and elevation).
2. Better geographical isolation. Because they're lower, their horizon area will be much, much smaller. This means their service areas can be more easily limited. This can be done with antenna geometry for geostationary orbit satellites, but in general they can still see almost an entire hemisphere of the earth, so they can still raise the noise floor in otherwise out-of-service areas.
3. Less delay. Geostationary orbits are far enough away that they introduce a delay that is unacceptable for most duplex applications (such as telephone or Internet traffic). Aeronautical platforms would be close enough to the ground that that delay would likely not be a factor.
4. More servicable. The cost of launching geostationary payloads means that the payloads must be designed for a long service life, which raises the cost of the payload significantly, as well as the risks. Aeronautical platforms simply have to come down for a landing, be serviced, and then take off and fly back to station.
5. Less chance of solar outages. Twice a year, there are a few days in a row where geostationary satellites transit the sun. Often, their signal gets drowned out when that happens. Aeronautical platforms stationed outside of the tropics, the problem can be avoided pretty easily (simply place the station to the north of the service area for the Northern hemisphere or to the south of the service area for the Southern hemisphere).
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1. What about night? These things are going to be unable to see the sun for several hours every day, instead of two days a year. You need to size the batteries to be capable of handling that period. That much weight on a solar aircraft would be difficult.
2. Wear and tear. High altitude aircraft will have to deal with high altitude winds, and have motors running constantly. You can bring them down to service them, but what if they crash. Ho
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2. Of course satellites need to last for 10 years - there's no way to service them at all. Their design, build and deployment costs are astronomical (heh) because of that. The equivalent costs of aeronautical platforms will be so much lower by comparison that
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QinetiQ believes that stratospheric platforms will rapidly become commercially viable and revolutionize future communications. High altitude platforms of this sort cou
Still a few bugs in this (Score:3, Funny)
"ground braking"
Obviously the return and land part of the project needs work.Re: (Score:2)
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In other words, a new braking system for the landing gear????
groundbreaking [209.161.33.50] (Link to Merriam-Webster)
First test will be... (Score:1, Funny)
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Troll sat alone on his seat of stone,
And munched and mumbled a bare old bone;
For many a year he had gnawed it near,
For meat was hard to come by.
Done by! Gum by!
In a cave in the hills he dwelt alone,
And meat was hard to come by.
http://tolkien.cro.net/talesong/troll.html [cro.net]
Wow! (Score:1)
mirror(dot) since slashdotted (Score:2)
early endurance == mechanics aloft (Score:2)
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BTM
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Lordy.
I feel like I've been through the wringer after 8 *hours* flying left-seat.
Thanks for the correction.
See Also ... (Score:2)
Red-eye? (Score:2)
Leaders on this are, surprisingly, AC Propulsion (Score:2)
During the day, the plane used thermals to try to maintain altitude on as little power as possible. Thermals are, of course, derived from solar power as well.
As battery and solar cell technology continues to improve, this challenge has gone from
excellent (Score:3, Insightful)
Could solar power help this one? (Score:2)
--
Solar power: the past present and future: http://mdsolar.blogspot.com/2007/01/slashdot-user
Is there any reason (Score:2)
http://perso.orange.fr/ballonsolaire/en-index.htm [orange.fr]
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You need to move around to remain stationary in the air. That's what helium balloons don't do.
weird info (Score:1)
Just because you find one haredi (ultra religious) woman on the staff, doesn't mean anything. The only Israeli university with a specific religious agenda is Bar Ilan, near Tel Aviv and even then it's not ultra-religious.
If you like Shulamit Levenberg, then I suggest you make a Wikipedia article for her, that's the idea of Wikipedia...
Not only 'solar powered' (Score:2)
I guess that if you have 90% of your energy coming from a fuel cell and 10% for solar cell, you're 'solar powered', but these 'solar powered' planes won't be able to stay forever in the air like a blimp would.