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Solar Plane Completes 24-Hour Flight

Posted by samzenpus on from the icarus-air dept.

asukasoryu writes "An experimental solar-powered plane landed safely Thursday after completing its first 24-hour test flight, proving that the aircraft can collect enough energy from the sun during the day to stay aloft all night. The record feat completes seven years of planning and brings the Swiss-led project one step closer to its goal of circling the globe using only energy from the sun. The team will now set its sights on an Atlantic crossing, before attempting a round-the-world flight in 2013." We ran a story about the flight's departure yesterday.

4 of 88 comments (clear)

  1. Uses by IflyRC · · Score: 4, Interesting

    I think that this technology will show up in military drones before we'll ever see it in general aviation. It sounds great for smaller drones that can stay aloft without ever needing to refuel. Speed is also going to be a huge factor. Most drones, I would think, do not need to fly that fast as most can be launched near the location in which they need to patrol.

  2. Re:Hybrid Planes by BlackPignouf · · Score: 4, Interesting

    Assuming that the solar irradiance you get on top of the atmosphere is 1360W/m2, 1 square meter worth of solar panel with 20% efficiency (e.g. the best SunPower crystalline silicon modules) would generate 270W of electricity.

    Airbus claims that the A380 consumes 3l/100km.passenger of fuel.
    At Mach 0.85 (~250m/s at 10km altitude), this represents 27l/h.passenger.

    Assuming 10kWh/l of fuel energy content and 50% efficiency of the turbofans (pulled out of my ...), that amounts to 135kW of mechanical power needed for every single passenger.

    Assuming an electrical motor with 100% efficiency, you would need 500m2 of solar panels for every passenger to generate the required electricity, but only during the day.

    The plane from TFA seems to have 200m2 of solar panels with 12% efficiency. It can get away with it because it is much lighter and flights much slower.

    Conclusion : The orders of magnitude just don't match, even with 100% efficiency => Commercial flights as we know them & photovoltaics are incompatible.

  3. Re:Probably not by Chibi+Merrow · · Score: 5, Interesting

    Um, maybe not. Huge wing span and slow? Perfect target. Not a useful payload. Hugh amounts of electronics needed by a drone and....the military doesn't care about the costs of fuel or operation. Land it. Fuel it up. Send it out again. This is not a military technology.

    Disclaimer: I work with the FAA on UAS system integration into the NAS, so my opinions are a bit coloured by my experiences.

    I don't think you're imaginative enough about the types of missions our military wants to fly. Yes, a slow moving large UAS is not useful for low altitude fast turnaround tactical type missions, but that's what a Raven is for.

    Something like this, though, would be invaluable for long duration surveillance type missions, like monitoring borders in Iraq and Afghanistan for weapons smuggling. Stick something like this at high altitudes to do autonomous surveillance and deploy more agile solutions on an as-needed basis to check out potential targets the high altitude UAS detects. The plans for UAS systems are very layered approaches, with room for little soldier-deployable RC craft, short ranged attack/reconnaissance craft, and high altitude, long-range, long duration surveillance craft.

    You might think that the military will just "land and refuel" a UAS when necessary because money is no object, but that implies the existence of established airbases in the theater the UAS will be operating in, or long travel times to and from its mission which further reduce their loiter time. So, no, it's not as simple as "money is no object".

    Honestly, the period that UASes are most at risk is on landing and take-off, both from hostile ground fire and just simple things like wind gusts dashing them against the ground or knocking them over. Having a UAS system that rarely has to land and take off would immensely improve their reliability and life expectancy.

    So in summary, yeah, I think the military would be very interested in this type of technology.

    --
    Maxim: People cannot follow directions.
    Increases in truth directly with the length of time spent explaining them
  4. How much juice was left? by tomhath · · Score: 3, Interesting

    What they proved is that they can make it through the night with fully charged batteries. What they didn't say in the article is whether the batteries would be charged back up by tonight if they had stayed aloft.

    Still an impressive feat, but I'll be even more impressed when they can show that it fully recharges while in flight.