solar plane June 13, 2005 10:15 PM
Duo harness sun for global flight
By Richard Ingham in Le Bourget, France
June 14, 2005
From: Agence France-Presse
EUROPEAN adventurers who made the first non-stop round-the-world flight by balloon now hope to take off in a long-range, solar-powered plane that can fly by night.
Bertrand Piccard, of Switzerland, and Britain's Brian Jones, who took the balloon Breitling Orbiter 3 on its global flight in 1999, announced overnight that their latest brainchild, Solar Impulse, had secured its first major funding and technical help.
At its launch some 18 months ago, Solar Impulse was a dream, "now we have a real project", Mr Piccard told journalists at the Paris Air Show.
He helped pull back a blue silk cover to reveal a scale model of the strange plane which, if other sponsors are found, should make its first flight in 2008 and, in 2010, go on a round-the-world mission.
Mr Piccard said it would promote a new era of aviation, in which planes would be clean, drawing on the almost infinite energy of the Sun rather than on the dirty, finite reserves of fossil fuels.
"Sustainable development will not be achieved by stopping the mobility of the people," he said.
The frail-looking, grey-painted craft looks similar to a military pilotless drone.
Its lanky wings measure some 80 metres across, equal in wingspan to that of the giant A380 Airbus, which also made its maiden public appearance at the French air show.
In contrast, though, Solar Impulse will weigh just two tonnes, the size of a large car, compared with the A380's 560 tonnes. It will also carry just a single passenger.
The power will come from 250 square metres of solar panels on the wings' upper surface. They will turn two engines, providing 40 horsepower of thrust - enough for a top speed of about 100km/h.
Batteries weighing 400 kilos will take up surplus electricity generated during the day and at night time, the plane will draw on that to help keep the engines going.
The battery reserves will not be enough by themselves. During the day, the aircraft will climb to around 10,000 metres and gradually glide down to 3000 metres at night time.
Solar Impulse's chief executive Andre Borschberg said a quarter of the estimated $US40 million ($52.15 million) cost of developing the aircraft was now assured.
The Belgian plastics and pharmaceutical giant Solvay, the first of the project's four "main partners", will provide expertise for the plane's light, but strong, composite body.
Other partners in lesser roles include the French planemaker Dassault Aviation. Its aircraft designers will provide advice on aerodynamics.
The French firm Altran Technologies, a specialist in solar-energy management and avionics, and the European Space Agency (ESA) are also involved.
ESA is making ground-breaking scientific discoveries available through its technology transfer program for European firms.
If Solar Impulse lives up to the Piccard-Jones vision, it could provide a technological leap forward for solar-powered aircraft.
The biggest problems are the relatively low efficiency of solar panels and the weight of batteries needed to store power.
Investment in research may yield big gains in these areas and also smarter ways of husbanding the panels' precious power.
Mr Borschberg said the round-the-world trip would unfold over five legs, each of which would last "three to five days".
Sixty specialists have already been working on the scheme over the past 15 months.
Their computer simulations showed Solar Impulse should fly from west to east, between 10 and 30 degrees north of the Equator, to take advantage of prevailing winds and expected sunshine.
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