Solar-Powered Plane Makes Runway Debut

MikeChino writes "The much-hyped Solar Impulse airplane just completed its first runway test, paving the way for a 20-to-25-day trip around the world next year. Conceived by Bertrand Piccard, the single-pilot plane successfully used its four solar powered motors to taxi around the runway. If all goes according to plan the plane will be able to fly day and night without fuel, signaling a bright future for solar-powered flight."

Better site?

[tjstork]

Kinda interesting they didn't have the dimensions of the solar plane readily available. From the pictures it looks like the wingspan is an easy 100 feet to carry how much, one guy? Wonder how big the wings would be to carry 200 passengers, oh, and where would get the energy to carry them at 600mph? Seems to me solar and flight are fundamentally at odds simply because you need vast surface area to get the energy to reach high speeds...but then, maybe it can work, almost like you optimize

solar powered plane energy = kw * wing area meters ^ 2 - kw * motor * mass * velocity ^ 2.
and
mass = wing density * wing area meters ^ 2

would have to factor in wind resistance from the giant wings, but that's cross sectional area, I thought, that causes drag, so if you made the wings really thin...

Insightfull my ass

[SmallFurryCreature]

This guy isn't insightful, he is a twit.

Not all planes are passenger planes. This plane would be perfect for unmanned or long range observation. Carrying all your fuel aboard becomes incredibly expensive the longer your range has to be. This plane solves that by refueling constantly while inflight.

Insightful? No, short-sighted, yes.

Re:Better site?

[Anonymous Coward]

This is all technically exciting, but they'll have to find a business use for this.

it looks like the plane can carry just a few kilos of cargo, and would go around the world in around a month, not too good for transport!

Maybe it would be good for earth observation, cheaper than satellites, more detailed images.
And then maybe an unmaned version.

It will be interesting to follow

Re:Let's do the math on this one... how many HP?

[ThosLives]

Well, this solar plane isn't so much a plane as it is a motor glider given the wingspan and aspect ratio. The motor is just enough to get it off the ground and help gain altitude when thermals and other updraft conditions are not present. Gliders seem to fly just fine and they have a zero power-to-weight ratio, so that argument is a bit naive. Gliders can also be fairly fast given the right conditions: there are high-performance glider races where the gliders fly around 200 knots over a course of about 180 nautical miles (although I wouldn't say the particular aircraft in this article would be a "high performance" aircraft).

Re:NASA already has a Solar UAV

[C0vardeAn0nim0]

that flight crew managed to restart the engines and made a powered landing in jakarta.

for a gliding landing all the way through, check air canada flight 143, AKA, gimli glider [wikipedia.org]

Re:Better site?

[elashish14]

Relax, it's just for research. They're not saying that it'll completely replace all airplane technology, or even that it will ever displace current jet fuel models - it's just something that's worthy of being looked into. Instead of asking ourselves if we can use this to fuel a jumbo jet, let's start with a simpler engineering problem and see if it's practical for powering, say, a 4-passenger private vehicle. Or maybe an unmanned drone for non-passenger purposes.

What is important about this is that if they can show that it's practical and stimulate some interest, then maybe they can get more funding and attention. That's why they have these prototype designs and demos - not cause they think it'll solve every energy-related problem the world faces. Sure, not every new, 'promising' technology ever turns out to be as great as we expect them to be; but if they weren't labeled as such, those few that actually have a chance of being viable would never receive attention.