Solar Impulse plane lands in Phoenix


Watch the solar plane touch down in the dark in Phoenix, Arizona

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A plane powered only by the Sun has completed the first leg of a journey that aims to cross the US.

Solar Impulse, as the vehicle is known, took off at dawn from San Francisco, California, on Friday and landed in Phoenix, Arizona, some 18 hours later.

The craft will stop over in Dallas, St Louis, Washington DC and New York in the coming weeks.

The plane has the same wingspan as an Airbus A340 but it weighs just 1.6 tonnes.

It has already made a day-and-night flight lasting more than 26 hours, and the team aims to eventually circumnavigate the globe in 2015.

The plane took off from Moffett Field on the edge of San Francisco Bay at 06:12 local time (13:12 GMT) on Friday, and landed at Phoenix's Sky Harbor Airport at 00:30 local time (07:30 GMT) on Saturday.

This meant Solar Impulse spent several hours flying in darkness, relying solely on the energy stored in an array of lithium-ion batteries to drive its propellers.

In daylight hours, these are charged by nearly 12,000 solar cells that cover the craft's wings and stabiliser.

The Solar Impulse HB-SIA

Solar impulse plane infographic
  • Wingspan - 63m (208ft)
  • Weight - 1,600kg (3,500lb)
  • Covered with 11,628 solar cells
  • Carries 400kg (900lb) of lithium-ion batteries
  • Maximum cruising altitude of 8,500m (28,000ft)

The HB-SIA craft was piloted by Bertrand Piccard, a co-founder of the effort, who is perhaps best known for being the first person to circumnavigate the globe in a hot-air balloon, in 1999.

The trans-America bid is the first attempt of its kind - flying in the hours of daylight and in darkness - with a zero-fuel aircraft.

Together with co-founder and entrepreneur Andre Borschberg, the pair of Swiss pilots have racked up a number of world records and milestones in recent years.

The first night flight of a solar-powered craft in 2010 was followed by a first inter-continental flight in 2012.

The two pilots will share the job of flying the plane between each of the stops of the tour.

"We've been preparing for this flight since last summer, so we are all very excited," Mr Borschberg told BBC News.

The current aircraft HB-SIA is effectively the prototype for the craft that will eventually be used for a round-the-world trip. The HB-SIB should be completed by the end of 2013.

"You should see this like being in 1915 when the pioneers were trying to do these first cross-country flights - still unable to cross the ocean, but an important step for the development of aviation," Mr Borschberg said.

The launch on Friday served as the start of the pair's Clean Generation Initiative, an effort to encourage policy-makers and businesses to develop and adopt sustainable energy technologies.

"We want to show that with clean technologies, a passionate team and a far-reaching pioneering vision, one can achieve the impossible," Dr Piccard said at the announcement of the mission in March.

Landing Solar Impulse co-founder, pilot and CEO Andre Borschberg (L) greets pilot Bertrand Piccard at Sky Harbor International Airport in Phoenix

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  • rate this

    Comment number 93.

    41. Mike
    4TH MAY 2013 - 18:41
    I'm sure the pentagon is already figuring out a way to strap missiles to it and bomb people.
    Yes I can see the day when there are thousand of these in the air bombing the bejeezus out of someone. It will be romantically referred to the Charge of the Light Brigade.

  • rate this

    Comment number 92.

    What I don't understand is why they have built a conventional aircraft. They are continually consuming energy just to provide enough forward momentum to give lift and keep it airborne. Why not use a helium airship and cover that in solar cells to drive electric propulsion. You might have a craft that actually has practical application. Sorry, I'm an engineer; always looking for the efficient.

  • rate this

    Comment number 91.

    It's how mankind progresses, a little new science at a time. It has enabled the Arts "celebrities" to tweet their breakfast details on their electronic devices to their "followers", so Science does go backwards sometimes to go forwards.

  • rate this

    Comment number 90.

    Certainly a very impressive piece of engineering, but I can't help wondering about the overall energy cost once you take into account all the energy needed to initially create the solar cells, composites, and batteries. Sure, let's go green where it makes sense. However, "fuel-less" aviation isn't the most practical demonstration.

  • rate this

    Comment number 89.

    A century ago the Wright brothers first flew a plane that had no payload capacity. They also introduced the principle of three-axis control. This lead to today's world-wide flying.

    This solar plane has no payload capacity but is demonstrating the application of solar & battery technology.

    Whilst this may not be as world-changing as the Wright's invention it is a significant technological step.

  • rate this

    Comment number 88.

    Good, this form of transport will save the planet from global warming. Snigger.

  • rate this

    Comment number 87.

    So, a very very light aircraft that starts pre-charged with enough power from ground level to get high enough to be up above cloud cover and get perpetual sunlight it could "orbit" the earth forever, using the daytime to collect enough power to see it through the nights? VERY Impressive engineering, but if it can't carry a payload, does it have applications other than surveillance?

  • rate this

    Comment number 86.

    Good stuff and progress towards more efficient use of energy and materials.

    If they fly above the UK and need a "hot air" boost then find a bloke called Nigel Farage and his team of "intelligentsia" for a boost ;-)

    This kind of cooperative project is something that anathema to them.

    Keep the project going guys it's potential is "sky high" (sorry)

  • rate this

    Comment number 85.

    Ian Macleod
    4th May 2013 - 16:42

    @1mrgoggle, they are Swiss not American. I wonder if they will ever be able to scale it up to carry passengers, that would be fantastic.

    No!!, ...but they could build a solar powered airship which would have about the same speed as this plane but a much higher lifting capability.

  • rate this

    Comment number 84.

    Omega will be hoping this story is attracting more interest in Amrica.

  • rate this

    Comment number 83.

    The Swiss voted to exit nuclear power by 2034 when the last of its reactors will shut down.

    Existing buildings must now undergo partial/complete renovations to assure energy efficiency. All new builds after 2020 will be self-sufficient in energy production.

    Kudos to the Swiss.

  • rate this

    Comment number 82.

    Hello World,
    I have a question.
    This is all amazing and everything else but the numbers don't add up....if the flight was 18 hours long (from San Fran to Phoenix) that would average 40mp/h ....was this not a direct flight? please elaborate....


  • rate this

    Comment number 81.

    A useless waste of time, money, and energy. There's nothing new or special about this, no technological innovation here. Just grandstanding for egoism.

  • rate this

    Comment number 80.

    I would like to know the design characteristics of the solar panels. EG: Weight, thickness, torsional strength etc. In laymans terms. Also. What is the cruising airspeed and how well does it handle wind shear. It looks a rather fair weather machine to me. But hey, I would certainly have a blast with the adventure and excitement.

  • rate this

    Comment number 79.

    I am more impressed with the smallest flying robot from Harvard and the atom sized movie from IBM both of which came out this week as well.

    This airplane is an interesting engineering accomplishment, but nothing especially innovative about using commercial PVs to charge lithium batteries to run electric lawnmower motors with propellers attached to them. It has been done before.

  • rate this

    Comment number 78.

    This is not a US project. It is Swiss. They are just flying over the US. Please give credit where credit is due. The Swiss deserve kudos for a job well done. On a side note, now I can watch all of the negative US comments turn into glowing praise for the same project.

  • rate this

    Comment number 77.

    As with many news stories these days one needs to check the facts - for those thinking this is an american project - it is in fact nearly 100% Swiss.

  • rate this

    Comment number 76.

    Nice to look at but this will never have a viable commercial application. You cannot carry hundreds of people or tonnes of cargo with a thing like this. It's just another stunt to make the cover of National Geograhic. It may have military applications, probably already does, the US is always seeking more efficient ways of killing people. Killer drones on solar power for months all over the world.

  • Comment number 75.

    This comment was removed because the moderators found it broke the house rules. Explain.

  • rate this

    Comment number 74.

    This achievement is as much about battery as solar cell technology. Both have advanced exponentially over the past few years and the potential for practical application is enormous. Worth checking out the patent applications and how China now features so large in these and associated areas. This is a US achievement but I suspect many commercial developments will arise elsewhere.


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