8 ms·

Solar Impulse lands in California after Pacific crossing

90 points by frgewut 10y ago

harwoodleon 10y ago
"He predicted that, 50 years from now, electric aeroplanes would be "transporting up to 50 people"." Shame the mega storms that are swirling the planet at that point will probably rip the planes out of the sky. 50 years too late if you ask me.
- chinathrow 10y ago
  What megastorms? Did I miss anything?
  - johnchristopher 10y ago
    GP might be referring to that http://www.scientificamerican.com/article/megastorms-could-down-massive-portions-of-california/ http://www.scientificamerican.com/article/megastorms-could-d... Megastorms Could Drown Massive Portions of California Huge flows of vapor in the atmosphere, dubbed "atmospheric rivers," have unleashed massive floods every 200 years, and climate change could bring more of them
  - throwaway5752 10y ago
    To busy to find links, but the gist is that Greenland Ice Sheet melting disrupts the conveyor currents that transport heat energy between the equator and the poles. Coupled w/ greater warming, the higher temperature differential would support stronger and more frequent cyclonic storms (supported by models, current trends, and archeological evidence).
    - stevetrewick 10y ago
      "The total number of hurricanes (particularly after being adjusted for improvements in observation methods) and the number reaching the United States do not indicate a clear overall trend since 1878" https://www3.epa.gov/climatechange/science/indicators/weather-climate/cyclones.html https://www3.epa.gov/climatechange/science/indicators/weathe... "Trends in tropical cyclone activity in the Australian region (south of the equator; 90–160°E) show that the total number of cyclones appears to have decreased to the mid 1980s, and remained nearly stable since. The number of severe tropical cyclones (minimum central pressure less than 970 hPa) is dominated by variability with periods of lower and higher frequencies of occurrence." http://www.bom.gov.au/cyclone/climatology/trends.shtml http://www.bom.gov.au/cyclone/climatology/trends.shtml "Similarly, the trend in intense tropical cyclones (minimum central pressure below 970 hPa) is not significantly different from zero." https://www.ipcc.ch/ipccreports/tar/wg1/091.htm https://www.ipcc.ch/ipccreports/tar/wg1/091.htm Or did you mean current trends in something else?
      - gozur88 10y ago
        Yep. All the falsifiable predictions have turned out to be, well, false.
- mspokoiny 10y ago
  I hope it would be earlier, 25-30 years maximum
barney54 10y ago
The Solar Impulse is really cool technology. It also shows why oil use has been so prolific. the energy-to-weight ratio of jet fuel is a marvel when you consider the size of today's jet aircraft and the distances they fly with hundreds of passengers.
- Retric 10y ago
  Flight actually scales up really well. Double the volume means less than double the energy required. So, larger craft can get a better cargo to energy efficency and or more speed. Solar impulse is large, but light and can carry two people plus stuff. Keep scaling it up, ditch the pilot, and you can have something between big slow boats and fast, but expencive jet aircraft. A full 50,000 lb 20' shipping container and 1 week China to US is probably viable. (Boats take 2 week to 1 month and unload at ports.)
  - dogma1138 10y ago
    Flight actually doesn't scale up that well, especially with solar.
    - Retric 10y ago
      OK, it's better than 1:1 vs cargo even for solar assuming you alter the design to fit your new scale. Beyond that, it's a question of what you want to call "Well" :)
      - dogma1138 10y ago
        No it doesn't scale 1:1 or any way else at least not in any specific manner. The scaling depends on how much lift you generate, the lift is a question of speed and your the available lift surface the nominal lift produced is then divided by surface area to give you your wing loading. Solar is pretty much the most inefficient way of powering virtually any aircraft because you needlessly increase the weight of the lifting surface and batteries weight considerably more than fuel and that weight is dead weight during the entire flight while a fueled aircraft becomes lighter. That said the scaling between the volume and the "surface area" isn't even in question here because you are going to be hitting a wall much quicker and that's takeoff weight as mentioned before lift is a factor of the surface area that can provide lift and the speed of the aircraft (as well as air density and some other things but lets ignore it) the heavier the aircraft the more energy you need to actually get to takeoff speeds, and when you make your lift surface bigger you increase drag as well as weight. The speed you can reach is going to be more or less limited because even a 100% efficiency solar powered engines are going to be limited to the max cell efficiency * cell surface area, the 2nd part of the equation is your wing surface and eventually there is a limit to how big your wings can be and still support themselves and most importantly not flutter. When you take all that and more into account there is absolutely no fucking way that you'll make an aircraft capable of lifting a 50,000lbs of crago, heck you won't build a solar aircraft capable of lifting 50,000 lbs of anything including itself. To put that into perspective 50,000lbs is 1/6th of the maximum structural load that a 747-8F (freighter) can carry, and about 1/4th of the nominal cargo load. To put it into even more perspective Solar Impulse weights 3000 lbs, it's maximum takeoff weight is about 4000 lbs and it has a max speed of 80km/h with a wing span greater than that of a 747. To put it simply there is no freaking way to scale this up, there is a good reason why nature haven't developed heavy flyers the heaviest bird capable of flight weights 35 lbs, the rule of thumb is that when you double the weight you need a 4th time as much wing area and spend 4 times more calories to achieve flight and while mechanical flight isn't exactly the same it's not that different - the amount of energy you can produce more or less limits how well you can fly because at the end if you stick 2 SRB's to a cargo container you don't even need wings. P.S. And that's before we getting into finding a material light enough to be viable for solar flight while still being able to bare the load of 50,000 lbs without collapsing, but even if you'll take perfect carbon nano tubes or any other super material you still won't be getting off the ground. If you want solar cargo air transport blimps are probably the way to go...
cubano 10y ago
I am surprised that no one has been developing (or I haven't heard of) fully autonomous airplane pilot systems. Something like that tied to a fleet of solar planes like this for shipping stuff could be a real game changer for certain types of cargo. Flying actually seems like a much "cleaner" environment for the AI to navigate then roads do, to be honest, and the dependence on instrumentation and not visual cues as much is of course a natural fit.
- zubiaur 10y ago
  There are several autopilots able to follow a route untethered with just waypoints. Apm (ardu pilot mega) and pixhawk come to mind. From what I've read it is still highly recommendable by the RC community to have telemetry links and if range allows, manual control. These modules are used mostly as flying aides but some companies are building RC planes with autopilot capabilities and market them towards the mapping and surveying industries, charging a hefty premium for it.
- tim333 10y ago
  >surprised that no one has been developing (or I haven't heard of) fully autonomous airplane pilot systems Facebook seems to be http://www.komando.com/happening-now/319972/facebook-is-building-a-massive-autonomous-drone-heres-what-it-looks-like http://www.komando.com/happening-now/319972/facebook-is-buil...
ruffrey 10y ago
Impulse propulsion flown by Piccard? Checks out
brianmcconnell 10y ago
Pilot here. I agree with other posts about energy density being an important factor here. I don't expect to see all-solar aircraft anytime soon. The best way to get aviation to become carbon neutral will be via biofuels, which several airlines are already experimenting with. That said, I can see a couple of areas where solar will contribute. While it will be very difficult to generate all of the power needed for an airliner via solar, there's no reason not to cover the aircraft in high efficiency (triple junction) solar cells. A large airliner will have a usable sky facing surface area of 1,000 square meters or so (rough estimate). Enough to generate a few hundred kilowatts of power. If the aircraft has hybrid gas/electric engines, that power can reduce the fuel burn a bit (even a small reduction is a big deal). I can also see where a serial hybrid design could be workable (e.g. lots of fuel cells generating electric power that in turn drives electric fans). This would be attractive, especially in smaller planes, due to the potential to reduce the risk of mechanical failure.

90 points by frgewut 10y ago

"He predicted that, 50 years from now, electric aeroplanes would be "transporting up to 50 people"." Shame the mega storms that are swirling the planet at that point will probably rip the planes out of the sky. 50 years too late if you ask me.

chinathrow 10y ago
What megastorms? Did I miss anything?
- johnchristopher 10y ago
  GP might be referring to that http://www.scientificamerican.com/article/megastorms-could-down-massive-portions-of-california/ http://www.scientificamerican.com/article/megastorms-could-d... Megastorms Could Drown Massive Portions of California Huge flows of vapor in the atmosphere, dubbed "atmospheric rivers," have unleashed massive floods every 200 years, and climate change could bring more of them
- throwaway5752 10y ago
  To busy to find links, but the gist is that Greenland Ice Sheet melting disrupts the conveyor currents that transport heat energy between the equator and the poles. Coupled w/ greater warming, the higher temperature differential would support stronger and more frequent cyclonic storms (supported by models, current trends, and archeological evidence).
  - stevetrewick 10y ago
    "The total number of hurricanes (particularly after being adjusted for improvements in observation methods) and the number reaching the United States do not indicate a clear overall trend since 1878" https://www3.epa.gov/climatechange/science/indicators/weather-climate/cyclones.html https://www3.epa.gov/climatechange/science/indicators/weathe... "Trends in tropical cyclone activity in the Australian region (south of the equator; 90–160°E) show that the total number of cyclones appears to have decreased to the mid 1980s, and remained nearly stable since. The number of severe tropical cyclones (minimum central pressure less than 970 hPa) is dominated by variability with periods of lower and higher frequencies of occurrence." http://www.bom.gov.au/cyclone/climatology/trends.shtml http://www.bom.gov.au/cyclone/climatology/trends.shtml "Similarly, the trend in intense tropical cyclones (minimum central pressure below 970 hPa) is not significantly different from zero." https://www.ipcc.ch/ipccreports/tar/wg1/091.htm https://www.ipcc.ch/ipccreports/tar/wg1/091.htm Or did you mean current trends in something else?
    - gozur88 10y ago
      Yep. All the falsifiable predictions have turned out to be, well, false.
mspokoiny 10y ago
I hope it would be earlier, 25-30 years maximum

barney54 10y ago

The Solar Impulse is really cool technology. It also shows why oil use has been so prolific. the energy-to-weight ratio of jet fuel is a marvel when you consider the size of today's jet aircraft and the distances they fly with hundreds of passengers.

Retric 10y ago
Flight actually scales up really well. Double the volume means less than double the energy required. So, larger craft can get a better cargo to energy efficency and or more speed. Solar impulse is large, but light and can carry two people plus stuff. Keep scaling it up, ditch the pilot, and you can have something between big slow boats and fast, but expencive jet aircraft. A full 50,000 lb 20' shipping container and 1 week China to US is probably viable. (Boats take 2 week to 1 month and unload at ports.)
- dogma1138 10y ago
  Flight actually doesn't scale up that well, especially with solar.
  - Retric 10y ago
    OK, it's better than 1:1 vs cargo even for solar assuming you alter the design to fit your new scale. Beyond that, it's a question of what you want to call "Well" :)
    - dogma1138 10y ago
      No it doesn't scale 1:1 or any way else at least not in any specific manner. The scaling depends on how much lift you generate, the lift is a question of speed and your the available lift surface the nominal lift produced is then divided by surface area to give you your wing loading. Solar is pretty much the most inefficient way of powering virtually any aircraft because you needlessly increase the weight of the lifting surface and batteries weight considerably more than fuel and that weight is dead weight during the entire flight while a fueled aircraft becomes lighter. That said the scaling between the volume and the "surface area" isn't even in question here because you are going to be hitting a wall much quicker and that's takeoff weight as mentioned before lift is a factor of the surface area that can provide lift and the speed of the aircraft (as well as air density and some other things but lets ignore it) the heavier the aircraft the more energy you need to actually get to takeoff speeds, and when you make your lift surface bigger you increase drag as well as weight. The speed you can reach is going to be more or less limited because even a 100% efficiency solar powered engines are going to be limited to the max cell efficiency * cell surface area, the 2nd part of the equation is your wing surface and eventually there is a limit to how big your wings can be and still support themselves and most importantly not flutter. When you take all that and more into account there is absolutely no fucking way that you'll make an aircraft capable of lifting a 50,000lbs of crago, heck you won't build a solar aircraft capable of lifting 50,000 lbs of anything including itself. To put that into perspective 50,000lbs is 1/6th of the maximum structural load that a 747-8F (freighter) can carry, and about 1/4th of the nominal cargo load. To put it into even more perspective Solar Impulse weights 3000 lbs, it's maximum takeoff weight is about 4000 lbs and it has a max speed of 80km/h with a wing span greater than that of a 747. To put it simply there is no freaking way to scale this up, there is a good reason why nature haven't developed heavy flyers the heaviest bird capable of flight weights 35 lbs, the rule of thumb is that when you double the weight you need a 4th time as much wing area and spend 4 times more calories to achieve flight and while mechanical flight isn't exactly the same it's not that different - the amount of energy you can produce more or less limits how well you can fly because at the end if you stick 2 SRB's to a cargo container you don't even need wings. P.S. And that's before we getting into finding a material light enough to be viable for solar flight while still being able to bare the load of 50,000 lbs without collapsing, but even if you'll take perfect carbon nano tubes or any other super material you still won't be getting off the ground. If you want solar cargo air transport blimps are probably the way to go...

cubano 10y ago

I am surprised that no one has been developing (or I haven't heard of) fully autonomous airplane pilot systems. Something like that tied to a fleet of solar planes like this for shipping stuff could be a real game changer for certain types of cargo. Flying actually seems like a much "cleaner" environment for the AI to navigate then roads do, to be honest, and the dependence on instrumentation and not visual cues as much is of course a natural fit.

zubiaur 10y ago
There are several autopilots able to follow a route untethered with just waypoints. Apm (ardu pilot mega) and pixhawk come to mind. From what I've read it is still highly recommendable by the RC community to have telemetry links and if range allows, manual control. These modules are used mostly as flying aides but some companies are building RC planes with autopilot capabilities and market them towards the mapping and surveying industries, charging a hefty premium for it.
tim333 10y ago
>surprised that no one has been developing (or I haven't heard of) fully autonomous airplane pilot systems Facebook seems to be http://www.komando.com/happening-now/319972/facebook-is-building-a-massive-autonomous-drone-heres-what-it-looks-like http://www.komando.com/happening-now/319972/facebook-is-buil...

ruffrey 10y ago

Impulse propulsion flown by Piccard? Checks out

brianmcconnell 10y ago

Pilot here. I agree with other posts about energy density being an important factor here. I don't expect to see all-solar aircraft anytime soon. The best way to get aviation to become carbon neutral will be via biofuels, which several airlines are already experimenting with. That said, I can see a couple of areas where solar will contribute. While it will be very difficult to generate all of the power needed for an airliner via solar, there's no reason not to cover the aircraft in high efficiency (triple junction) solar cells. A large airliner will have a usable sky facing surface area of 1,000 square meters or so (rough estimate). Enough to generate a few hundred kilowatts of power. If the aircraft has hybrid gas/electric engines, that power can reduce the fuel burn a bit (even a small reduction is a big deal). I can also see where a serial hybrid design could be workable (e.g. lots of fuel cells generating electric power that in turn drives electric fans). This would be attractive, especially in smaller planes, due to the potential to reduce the risk of mechanical failure.