14 Apr '10 08:18>
Wow.
http://www.solarimpulse.com/sitv/index.php?lang=en
http://www.solarimpulse.com/sitv/index.php?lang=en
Originally posted by avalanchethecathttp://en.wikipedia.org/wiki/Solar_Impulse#Proposed_circumnavigation
Wonder if it goes fast enough to stay ahead of the terminator? Or does it have to land in the evening?
Originally posted by zeeblebotDid you hear the radio transmission about the takeoff speed? 27 knots. The plane is loaded with Li-ion batteries to fly at night, at least the full version will. This flight got to about 45 meters, a bit better than the one meter of my post. They are taking it one step at a time. One thing clear, the body of that plane would not take much sheer stress, it could be torn apart by bad downdrafts. Wonder why they didn't coat the whole body and rear tail structure with PV?
22,858.729 miles / 24 hours = 952.447041667 mph
952 mph / 761.2 mph = Mach 1.25.
i'm guessing a solar-powered aircraft is not going to make Mach 1.25 anytime soon:
http://en.wikipedia.org/wiki/File:FA-18_Hornet_breaking_sound_barrier_(7_July_1999).jpg
http://upload.wikimedia.org/wikipedia/commons/thumb/c/cc/Flea_Hop_HB-SIA_-_Solar_Impulse.jpg/450px-Flea_Hop_HB-SIA_-_Solar_Impulse.jpg
Originally posted by zeeblebotAnd I'm guessing never. There probably simply isn't enough energy in sunlight to achieve supersonic speeds. If it was necessary to charge up over a number of days before going supersonic (and going round the earth) then the whole point (keeping up with the sun in order to provide power) would become unnecessary.
by "anytime soon" i meant the next century. although upon further reflection, i guess with exponential tech growth we could see something in the next 50-500 years.
Originally posted by zeeblebotTalking about mach 1 or better solar powered flight. That would seem impossible considering the amount of energy available only from the surface area of the wings. I suppose battery or some other form of energy storage could allow a slow flight that lasted days or weeks and excess energy stored enough to make a quick dash to supersonic flight for a few minutes but then you would run out of energy and be back to regular flight of a couple hundred klicks or less.
by "anytime soon" i meant the next century. although upon further reflection, i guess with exponential tech growth we could see something in the next 50-500 years.
Originally posted by zeeblebotThe problem with solar flight is using solar energy just to stay in the air. A better system would be just using a helium dirigible paved with light PV panels and using that for propulsion only, not lift. It seems obvious to me a much more efficient use of solar energy, to say nothing of by design having a hundred times the surface area for energy collection. More lift power to have much more battery storage onboard to get through nightimes and storms, maybe even a tethered version to just collect energy to use on the ground. I can even see a system that uses H2 as a lift gas, for one thing it is more efficient then helium, much more readily available and if used as a tethered PV collection site, some of that energy can be used for electrolysis of water to regenerate H2 to make up for losses through the skin, something you cannot do with helium. If it is unmanned, who cares if the dam thing blows up other than the annoyance of replacement, no lives would be lost.
you're both right 🙂. i was thinking more of the materials tradeoff, like sonhouse.