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Solar Impulse 2: Test flight carried out in Switzerland

2 June 2014 Last updated at 08:22 BST

A solar-powered plane that will attempt to fly around the world in 2015 has made its first test flight after taking off in Switzerland.

Solar Impulse 2 is a larger, upgraded version of the aircraft that flew across the United States last year.

Project leaders Bertrand Piccard and Andre Borschberg say they want to push the boundaries for alternative energy.

Mr Piccard explained the carbon-fibre aircraft had a wingspan wider than a Boeing 747 jet, but weighed only 2.3 tonnes.

Footage courtesy of Solar Impulse.