Slashdot Mirror
Solar-Powered Plane to Fly Around the World
securitas writes "The BBC's Carolyn Fry reports on the Solar Impulse project, a plan to circumnavigate the globe in a solar-powered airplane. Adventurers Brian Jones and Dr. Bertrand Piccard, who were the first people to circumnavigate the globe in a balloon in 1999, are behind the Solar Impulse project. The project is proceeding to the design stage after a feasability study determined that the solar-powered airplane concept is a viable idea. While other solar-powered planes like the Helios prototype have relied on a secondary power source (fuel cells), this project will be powered by solar energy alone. Batteries will store energy received in daylight hours to fly all night. The first prototype is scheduled for launch in 2006."
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" [google.com].
Big spotlights on the ground shining up at the plane as it goes by!
The spotlights will be powered by a combination of coal powered power stations in urban areas, ancient russian nuclear reactors... and furnaces powered by burning kittens.
But the light is enviro friendly!
How would it be to fly close to the pole that has summer. There the night is very short. And the distance is short.
You're probably thinking of journalist Nellie Bly (pseudonym of Elizabeth Jane Cochrane), who left New York on November 14, 1889 and returned on January 25, 1890, beating Phileas Fogg's fictional journey by over a week. Phileas Fogg was a character in Jules Verne's novel "Around the World in 80 Days," published in 1872.
[now drifting irremediably OT] "Around the World in 80 Days" was a hell of a good movie, based on Verne's novel, which was released in 1956. It was filmed in Todd-AO--one of a handful of movies filmed in that process. It was spectacular and gorgeous and a lot of fun to watch. It had quite a cast, David Niven as Phileas Fogg and Cantinflas as Passepartout. Only bad part was that the theme, which was quite catchy, had become a hit tune and had been played on the radio so often that by the time I saw the film--this was in the days when movies stayed in theatres for more than a couple of weeks, and in the case of Cinerama and Todd-AO spectaculars it could have been months--everybody was thoroughly sick of the theme music.
"How to Do Nothing," kids activities, back in print!
The solar cells will charge batteries. The batteries will power a bank of flashlights that will keep the wings illuminated at night.
Helios used fuel cells to *store* energy from the solar cells in a closed system. This new project uses *batteries* to perform the same function. Therefore, the phrase this project will be powered by solar energy alone is not correct in implying there is anything significantly different than the Helios.
(BTW, I did some minor work on the Helios fuel cells)
Visit the best Liberal Blog: DU
Don't know about the 1970's, but I sure remember reading about it at the end of November. Hmm. The story makes Slashdot on the day of the announcement, and the BBC is a month behind? Maybe it's not as bad around here as some would have us believe... ;)
UNIX? They're not even circumcised! Savages!
Indeed.
Everybody knows that the God wants us to burn oil, gas and coal.
Bomb anyone who thinks to the contrary.
The owls are not what they seem
"Batteries will store energy received in daylight hours to fly all night."
Why not just fly the other drection and stay in the sunlight?
Earth's circumference: around 24,000 miles.
Hours in a day: around 24.
Speed of Earth's rotation at surface: around 1,000 miles per hour.
Look on your face as the sun goes wooshing past your solar plane: priceless.
If a manned solar-powered plane can fly around the world, then one could conclude that an unmanned solar-powered plane could reliably operate for indefinate periods of time above a city or region while carrying a substantial payload.
We can create controllable aircraft that don't ever have to land. That's huge.
Such a plane could function as the equivalent of a local communications satellite, with the latency benefits of not being thousands of miles away in geosync orbit. It could transmit and receive line-of-sight microwave communications with hundreds of thousands of people. It could relay data to other planes hundreds of miles away. It would also be several orders of magnitude less expensive to fly, and would be maintainable.
Businesses are spending hundreds, sometimes thousands, of dollars a month on reliable private communications between their offices in the same city. There is definately a market for this.
Thw Wright brother's flyer did not transport any cargo. The first artificial satellite did nothing other than send a radio beep. The first digital computer filled a large room and was about as powerful as the processor in your wristwatch.
Things start small. Get a clue.
Where is this a quote from? The article and site show an aircraft with traditional propellers on its tail.
What ESA is claiming is new about this mission
European Space Agency? Where were they mentioned?
is that they'll be combining ion propulsion with gravity assist maneuvers
Aircraft, as a rule, do not perform gravity assist maneuvers. It's a horrible faux paus.
The parent was likely cut-n-pasted from somewhere else. Moderate appropriately.
Back for a return engagement..
Around the World in a Solar Plane
The Piccards are well known for scientific exploration and adventure. Bertrand went around the world in the a balloon. The Piccard family is known as the inventor of the modern hot air balloon. Here is info on Don Piccard, one of his relatives. The bathyscaphe used to explore deep ocean areas was developed by Auguste Piccard. I've had the pleasure of speaking with Don Piccard before. Great family all around.
In one sense they are in that hydrogen is usually seen as an energy storage mechanism rather than a source (i.e. there aren't many natural sources of pure hydrogen). However, the relevance to this article is that the hydrogen fuel cells on helios were filled with hydrogen on the ground before takeoff, not filled with hydrogen during flight (presumably from electrolyzed water vapour, the electricity being provided by the solar cells). These batteries will be charged by the solar cells during flight.
This has already been discussed on /.
But maybe I could get even better karma by reposting my old comments into this new thread?
No reason why it wouldn't be manned.
They state a 60 meter wingspan. That would like be about 6 meters wide, if they keep a 10-1 ratio. The ground and sea also reflect a certain percentage of solar energy. Overall, it looks to me that the would have about 360m^2 of direct sunlight potential and about the same amount of reflected sunlight.
The solar power is about 1.3kw/m^2. That is 460KW of direct energy. If they get a 30% reflection on the underside, that is another 140KW of potential energy. About 600KW total. Figure about 15% efficiency and you get about 90KW of power. That is about 120 HP, which is the same power as the rear engine of used on Voyager on it's round the world flight. Electric engines have an advantage here in that they don't lose power with altitude, so their effective engine power at altitude would be higher than that used on Voyager.
Voyager only required two engines for take-off and to provide a secondary engine in case of problems with the first. The weight here will be constant throughout, so they will not need a second engine for take-off. (Voyager was basically a flying fuel tank on take-off and needed 300HP to take-off on it's runway. Once airborne, it only needed 110HP. Without all the fuel on board, 110HP was enough for take-off).
Also, solar panel efficiency improves with a slight reduction in temperature, so they might manage better solar efficiency.
Hmm. There is a dodge I wonder if they have considered. One of the problems with that they are doing is the weight. They have a background in ballooning. I wonder if they have considered incorporating sealed helium bladders in the wings and other areas that are not going to be occupied by people. If they can lower the effective density of the aircraft, then they will effectively lower it's weight. Not sure if it is worth the effort though. The other would be use open those sections to the air, then allow the heat from the solar panels heat the inner wings also effectively lowering the density of the aircraft, but this would not be as effective.
No reason why it wouldn't be manned.
:)
Especially given that the pictures show what look like cockpit windows
They state a 60 meter wingspan. That would like be about 6 meters wide, if they keep a 10-1 ratio. The ground and sea also reflect a certain percentage of solar energy. Overall, it looks to me that the would have about 360m^2 of direct sunlight potential and about the same amount of reflected sunlight.
There is also the fuselage and the horizontal stabaliser.
Voyager only required two engines for take-off and to provide a secondary engine in case of problems with the first. The weight here will be constant throughout, so they will not need a second engine for take-off. (Voyager was basically a flying fuel tank on take-off and needed 300HP to take-off on it's runway.
Constant weight throughout the flight means also that the trim does not need altering to compensate for burning fuel.
I mean really, WHY ? Just because they think they can ? What are the possible implication in a commercial market ? NONE....
A plane which can fly around the world on solar power means that it can stay in the air indefinitly. Such a plane could perform functions carried out by comsats, but would be a lot cheaper and potentially recoverable for servicing and upgrading.
Now if someone said they were going to fly around the world on NATURAL GAS, or Cow Shit, that would be cool. Seriously, a LNG plane would be cool, and there are a lot of reasons to do it,
You could power a plane on compressed methane, except that the tankage you'd need is more complex and heavier than the liquid fuels used now.
but SOLAR is NOT going to be powering any transport planes in the near future.
A large part of the takeoff weight of a plane is fuel.