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."

Comments

Re:Better site?

[OeLeWaPpErKe]

You'd need some place to put the solar panels, which will also put a lower limit on wing surface, because there's a minimum amount of energy you'll need.

Then due to this plane not exactly flying at 900 kph, you'd need short wings to prevent it from stalling due to the wind movement created by flying over a cow that's thinking about farting.

So you need a minimum wing surface, and you need a relatively short wing. Your only choice is going wide.

Now add to that that the maximum weight of the plane is obviously very limited (and you already have the pilot, so you add 300 pounds for safety). In essence those enormous wingspan cannot be supported by a structure that's internal to the wing, as that would add too much weight. So you have 3 cockpits : 1 manned, 2 unmanned. 3 planes "loosely" connected (some sort of elastic bands, apparently).

So you get this plane : it's really 3 planes connected to eachother at the wingtips. This is necessary due to low-speed flying and the need to collect energy. Before you ask about making a jetliner carrying 300 people solar-powered ... does it really need to be stated that's not going to happen ? It would need a wingspan of several miles, and would fly perhaps 100-150 kph.

The real reason these planes are getting built is their potential to replace satellites, and even cell towers. Once we have commercial autonomous planes that can keep flying for 10 years at, say, 15 km height we don't need satellites anymore. Furthermore, these planes would be satellites that have other advantages, like the fact that they can actually operate with an antenna gain less than 500 (no need for dishes). They would not introduce a significant delay (satellite communication low-earth-orbit adds somewhere near 300 msec transit time, geostationary ones add close to a second. Nobody, even non-gamers, like pingtimes more than a second).

And best of all : they're mobile. Can you imagine ? Some 3rd world or muslim dictator decides to grow some brains and steps down. The parliament votes to create a communications infrastructure, and asks $carrier to do so. Carrier launches 30 (or whatever number required) of these planes from a location deep within the united states, and 5 days later the entire country is covered in a completely functional cell phone network that does not require uplinks (beyond the planes themselves). The same network provides internet and television services. Whether a carrier needs to provide coverage in central manhattan or northeast pakistan, the infrastructure deployment process is identical : just build the plane. No permission (beyond countrywide flight permission that is), no pulling fiber, no renting roof space, no ...

And the military applications are equally great. Want to attack a country ? How about a permanent rocket launch basis in the sky that does not ever need to come down ?

Re:NASA already has a Solar UAV

[Goffee71]

oh, big planes can glide a loooong way - http://en.wikipedia.org/wiki/British_Airways_Flight_9